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Can particle beams be used to treat cancer? · Daniel and Kelly’s Extraordinary Universe

0:08
Speaker 1: Particle physicists love playing with big, expensive toys. The large
0:13
Speaker 1: Hadron collider in Switzerland costs more than ten billion dollars,
0:17
Speaker 1: and hey, what is it good for? Well, you know,
0:20
Speaker 1: understanding the nature of the universe and revealing the fundamental
0:24
Speaker 1: properties of matter, energy, space, and time. It's a pretty
0:27
Speaker 1: good deal if you ask me. But it's not just that.
0:31
Speaker 1: Basic research has also created lots of technology that improves
0:34
Speaker 1: our lives, including all of the electronics you're currently using
0:38
Speaker 1: to listen to me on this podcast. But particle physics
0:41
Speaker 1: has more directly saved lives as well. Usually we think
0:45
Speaker 1: of particles as dangerous of radiation as a cause of cancer,
0:50
Speaker 1: but what if particle physicists could do something useful for
0:53
Speaker 1: Once Today on the pod, we'll be asking what if
0:56
Speaker 1: particle beams could be used to treat cancer. Welcome to
1:01
Speaker 1: Daniel and Kelly's Extraordinary Practical Universe.
1:18
Speaker 2: Hello.
1:18
Speaker 3: I'm Kelly Winersmith. I study parasites and space and I'm
1:21
Speaker 3: excited to be talking about newer ish treatments for cancer today.
1:25
Speaker 4: Hi.
1:25
Speaker 1: I'm Daniel. I'm a particle physicist and I didn't get
1:29
Speaker 1: into it to save anybody's life, but I'm happy if
1:31
Speaker 1: it does.
1:32
Speaker 3: Yeah, today we're talking about a practical application of your work. Amazing, amazing,
1:38
Speaker 3: And so I know that for some kinds of mathematicians,
1:42
Speaker 3: if it turns out that their basic research has applications,
1:46
Speaker 3: they're like almost bummed out because it makes it less pure.
1:51
Speaker 3: How does the particle physics community feel about this amazing
1:55
Speaker 3: application of their work?
1:56
Speaker 1: The broader community, I think is positive because they're always
1:59
Speaker 1: looking for way to sell fundamental science to politicians and
2:03
Speaker 1: to the general public that don't understand that, like any
2:05
Speaker 1: investment in basic science is a good idea because it's
2:09
Speaker 1: going to yield something in the long term, and they're
2:10
Speaker 1: looking for something in the short term to use as
2:13
Speaker 1: an example. For me personally, it's a bit more mixed.
2:17
Speaker 1: I got into particle physics because it has almost no
2:20
Speaker 1: immediate applications because, as you know, my parents worked in
2:23
Speaker 1: the weapons program, and I was like, it's a little
2:26
Speaker 1: morally complicated to be building weapons of mass destruction pointed
2:29
Speaker 1: at civilian populations, which is basically what they were doing,
2:33
Speaker 1: and so I was glad that there were no immediate applications.
2:37
Speaker 1: So the idea that you're now building particle beams and
2:39
Speaker 1: pointing them at people. I'm glad that that's a positive thing.
2:43
Speaker 1: So I can imagine how there might be other uses
2:46
Speaker 1: for high intensity particle beams pointed at people's headsikes. So yeah,
2:50
Speaker 1: I think I would just prefer if the applications were
2:52
Speaker 1: more downstream so I didn't have to think about it.
2:54
Speaker 3: Oh you feel like at some point they're downstream enough
2:57
Speaker 3: that you don't have to worry. What if somebody tomorrow
3:00
Speaker 3: I did say, Okay, this particle beam stuff results in
3:03
Speaker 3: weapons of mass destruction, but it's twenty steps away. Does
3:07
Speaker 3: that absolve you?
3:09
Speaker 1: As long as it's like, you know, twenty generations and
3:11
Speaker 1: I'm dead when they build the torment nexus from all
3:15
Speaker 1: of my particle physics work, then I think it's not
3:17
Speaker 1: really my fault. What can I do about it?
3:19
Speaker 4: All?
3:19
Speaker 3: Right? Fair enough? Yeah, I guess you can't see the
3:21
Speaker 3: implications generations down the line in some cases.
3:24
Speaker 1: But I do, in general think it's a really interesting
3:26
Speaker 1: philosophical and moral quanity, because the only way to prevent
3:29
Speaker 1: people from using ideas to build things to torture people
3:34
Speaker 1: is to have no ideas and to make no advances.
3:36
Speaker 1: And I think that's ridiculous, and so I think we
3:39
Speaker 1: have to take leaps forward into the future and understand
3:41
Speaker 1: the universe, knowing that it's going to change society. We
3:44
Speaker 1: just hope for the better.
3:45
Speaker 3: Yeah, I totally agree, and so trying to think about
3:48
Speaker 3: how we unroll these new technologies without having too many
3:51
Speaker 3: negative implications, I soonish got me thinking about this topic
3:54
Speaker 3: a lot, and I feel like we need to be
3:56
Speaker 3: having a lot more conversations about how these technologies could
4:00
Speaker 3: be used. But on the plus side, we don't have
4:02
Speaker 3: to dig into too much of that today because this
4:05
Speaker 3: is an unmitigated good.
4:07
Speaker 1: Yes, exactly, all of those taxpayer dollars spent on building
4:12
Speaker 1: particle colliders have resulted in saving people's lives by curing
4:16
Speaker 1: their cancers, and so today on the podcast we'd be
4:19
Speaker 1: talking about exactly that topic. How exactly can you use
4:23
Speaker 1: Daniel's ridiculously abstract research with his ten thousand friends to
4:27
Speaker 1: cure cancer.
4:28
Speaker 3: I love that you have so many friends, Daniel. That's fantastic.
4:31
Speaker 3: You're very likable, though I'm not surprised.
4:33
Speaker 1: Well, I'm rounding them all up to friends. I'm sure
4:35
Speaker 1: there's some haters in that community.
4:37
Speaker 3: Oh, I say, yeah, I've got that too.
4:39
Speaker 1: So I went out there and asked our audience if
4:41
Speaker 1: they had an idea for how particle beams could be
4:44
Speaker 1: used to treat cancer, and we're very delighted to have
4:47
Speaker 1: their extemporing the speculation here on the podcast for you
4:51
Speaker 1: to enjoy. If you would like to contribute for future episodes,
4:54
Speaker 1: please don't be shy, write to us two questions at
4:56
Speaker 1: danieland Kelly dot org. Here's what people had to say.
5:01
Speaker 1: Particle beams are shot into the cancer at high speeds
5:05
Speaker 1: and just shake it up from the inside out until
5:08
Speaker 1: there's nothing left. Directed with magnets would focus on the cancer,
5:14
Speaker 1: target the specific cancer cells.
5:17
Speaker 2: Radiation treatments which basically kill the cancerous cells.
5:22
Speaker 1: Through very finely targeted obliteration. Using a high energy particle beam,
5:27
Speaker 1: you can destroy the cells in a very targeted way.
5:30
Speaker 1: It just deteriorates the cell growth.
5:33
Speaker 3: Particle beams disrupting the DAYNI of the particular cancer cells.
5:38
Speaker 1: Zapping a location a cancer with political beam.
5:45
Speaker 2: The beams heat the cancer and stops it from metastasizing.
5:49
Speaker 4: So picking up on context clues here, it's got beam
5:51
Speaker 4: in the name, and I'm pretty sure the main way
5:54
Speaker 4: cancer is treated is by destroying cancer cells. So my
5:57
Speaker 4: answer is via destruction of some kind from all different directions,
6:01
Speaker 4: so that those beams all intersect in the exact shape
6:05
Speaker 4: of the tumor, fry the area.
6:08
Speaker 1: The particles in the beam are specifically targeted at the
6:13
Speaker 1: areas in which the cancer is.
6:16
Speaker 2: My energy protos immitted from a cyco latron go through
6:19
Speaker 2: a lens that is shaped like the patient's tumor, so
6:25
Speaker 2: that it goes no deeper than the.
6:27
Speaker 1: Tumor, focused on the cancer cells directly, so that they'll
6:32
Speaker 1: form a constructive interference.
6:35
Speaker 3: Concentrated focused therapeutic particle beams directed at solid tumors reduce
6:39
Speaker 3: their viability. The particles damage the Maligan cells DNA.
6:43
Speaker 2: The high energy in the gamma range damages their DNA,
6:45
Speaker 2: so they can't replicate themselves anymore.
6:47
Speaker 1: I would think, by killing everything in their way, and
6:50
Speaker 1: thereby also killing the cancer.
6:53
Speaker 3: These are super fantastic answers. It sounds like a lot
6:56
Speaker 3: of people have heard of this before and so sort
7:00
Speaker 3: of on the periphery of their knowledge. At least, I
7:04
Speaker 3: hadn't heard about this until there was a case of
7:07
Speaker 3: cancer in my family where we were thinking about this
7:09
Speaker 3: as a treatment. Everything turned out okay. My sense is
7:12
Speaker 3: that this isn't in the public consciousness aside from people
7:15
Speaker 3: who have to think about this sort of treatment. But
7:18
Speaker 3: maybe I'm wrong, because it does seem like almost everybody
7:20
Speaker 3: had an answer that was like kind of on target.
7:23
Speaker 1: I think I knew roughly how this works, you know.
7:26
Speaker 1: I knew that when you get cancer, your options are
7:29
Speaker 1: like chemotherapy drinking poison basically, or radiation shooting particles at it,
7:35
Speaker 1: or surgery trying to cut it out. In all cases,
7:38
Speaker 1: they're like versions of localized suicide, like let's try to
7:41
Speaker 1: kill this part of my body before it kills the
7:43
Speaker 1: rest of me. Yeah, But until a couple of friends
7:46
Speaker 1: had weird growths in their brains recently and it really
7:48
Speaker 1: had to make this decision, radiation or surgery never really
7:53
Speaker 1: dug into the details the physics of like how does
7:56
Speaker 1: a particle beam hurt a tumor how do you aim it,
7:59
Speaker 1: how do you make sure you get to the right spot,
8:01
Speaker 1: what kind of particle should you use? So I thought
8:04
Speaker 1: it'd be really valuable for people to have some sort
8:05
Speaker 1: of understanding of this, so that in the moment when
8:08
Speaker 1: they're faced with these decisions, maybe they have some understanding
8:11
Speaker 1: of these options and what's really going on and the risks,
8:14
Speaker 1: and so when the doctor says this is going to
8:16
Speaker 1: swell your brain or this is going to do that,
8:18
Speaker 1: or this is going to damage the other tissue, it
8:20
Speaker 1: makes sense to you and helps you make those decisions.
8:23
Speaker 3: So radiation is different than the particle beams.
8:27
Speaker 1: It's the same.
8:27
Speaker 3: Yes, it is the same.
8:28
Speaker 1: By radiation, I just mean shooting particles and we'll get
8:31
Speaker 1: into that in a minute. But yeah, radiation particle beams.
8:34
Speaker 1: To me, it's the same deal.
8:35
Speaker 3: Excellent, all right, So let's start with, you know, probably
8:38
Speaker 3: the most interesting part the biology.
8:41
Speaker 1: That's why this is another fun topic because I was like, ooh,
8:44
Speaker 1: physics curing biological issues.
8:47
Speaker 3: Yeah yeah, although I think at the top of my
8:49
Speaker 3: list of fun is not cancer, but what cures for
8:53
Speaker 3: cancer is pretty awesome. So go ahead, let's hear the
8:56
Speaker 3: physicist explanation for what is cancer?
9:00
Speaker 1: Wait, I'm explaining it. I was hoping that. Well, I'm
9:04
Speaker 1: going to give it a start and you chime in
9:06
Speaker 1: with your informed details.
9:08
Speaker 3: Okay.
9:08
Speaker 1: My understanding is it's a whole collection of things, like
9:11
Speaker 1: they have something in common, but you can't really say
9:14
Speaker 1: cancer is like one thing in general. It's cells growing
9:18
Speaker 1: out of control, but the causes for that can be manyfold, right.
9:21
Speaker 3: Yeah, I have a friend who studies cancer, and he
9:24
Speaker 3: was telling me that even just one kind of cancer
9:27
Speaker 3: can be caused by so many different mutations that that
9:30
Speaker 3: makes it pretty difficult to treat because often you want
9:33
Speaker 3: to know exactly what kind of mutation it is that
9:35
Speaker 3: causes it. And so now we genotype people's cancers to
9:38
Speaker 3: try to figure out exactly which of the many mutations
9:41
Speaker 3: is causing it to target our treatment. So, yes, it's
9:43
Speaker 3: a lot of stuff that can cause cancer, but don't
9:46
Speaker 3: let that keep you from sleeping at night.
9:50
Speaker 1: But in general, it's when something goes wrong with the
9:52
Speaker 1: cell's growth function. Right, So cells are constantly replicating, called
9:56
Speaker 1: this mitosis, and the nucleus like splits the DNA and
9:59
Speaker 1: copy itself, and there's a whole bunch of genes that
10:02
Speaker 1: control that copying, but errors can creep in, of course,
10:06
Speaker 1: and then cells keep doing this duplicating themselves, copying themselves
10:09
Speaker 1: for a while, and then they stop. And this apoptosis
10:12
Speaker 1: is when it sells like I'm done, disassembles itself and
10:15
Speaker 1: gets like reabsorbed into the body. And this huge variation.
10:19
Speaker 1: Like some cells only live for like very short periods,
10:22
Speaker 1: like a day. Bone cells can live for like thirty years.
10:25
Speaker 1: Neurons can live forever. So you have this whole mechanism
10:28
Speaker 1: where cells are splitting and making copies of themselves and
10:31
Speaker 1: eventually retiring. In order to get cancer, a bunch of
10:34
Speaker 1: things have to go wrong in just the right way.
10:36
Speaker 1: So it's kind of amazing that cancer happens as often
10:39
Speaker 1: as it does because it requires like multiple mutations, multiple
10:43
Speaker 1: wye for this whole process to go wrong.
10:45
Speaker 3: Yeah, I'm gonna go ahead and give you a pod
10:47
Speaker 3: in biology, congratulations.
10:52
Speaker 1: So the first thing that has to go wrong is
10:54
Speaker 1: that the gene that controls how often you're going to replicate, right,
10:58
Speaker 1: these oncogene the genes that control replication have to go crazy.
11:02
Speaker 1: So maybe there's like a mutation, or maybe you just
11:05
Speaker 1: got a bad gene from your parent or something, and
11:08
Speaker 1: this gene that controls how often your splinting can go crazy,
11:11
Speaker 1: so you just get like uncontrolled replication instead of like
11:15
Speaker 1: doing it at a reasonable rate.
11:16
Speaker 3: Yeah, it could be because you got a gene from
11:18
Speaker 3: your parents. It could be because you were exposed to
11:20
Speaker 3: something that caused a bad change in your genetic code,
11:23
Speaker 3: you know. For example, that's what happens with skin cancer
11:26
Speaker 3: is you acquire a lot of mutations from the sun,
11:29
Speaker 3: which I know well and where your sunscreen. Kids.
11:32
Speaker 1: Fascinatingly, that's an example of radiation causing cancer right there.
11:37
Speaker 1: What's happening are like ultraviolet photons are penetrating into your
11:41
Speaker 1: body and causing damage to your DNA, which triggers cancer.
11:45
Speaker 1: So for a lot of people they connect radiation with
11:47
Speaker 1: the cause of cancer instead of the cure of cancer.
11:50
Speaker 1: And actually radiation can end up on both sides of
11:53
Speaker 1: that equation.
11:54
Speaker 3: Yeah. Yeah, but I think instead of fascinatingly, I would
11:56
Speaker 3: have said something like suckily or tragically. Yeah. I have
12:01
Speaker 3: a big scar on my forehead, which my daughter will
12:03
Speaker 3: sometimes be like, oh it's hard to look at, mom,
12:06
Speaker 3: and I'm like, kiss my butt, kid, But you don't
12:09
Speaker 3: have to live with it anyway.
12:11
Speaker 1: Is that a scar from a cancer removal?
12:13
Speaker 2: Yeah?
12:14
Speaker 1: Yeah, glad they caught it.
12:15
Speaker 3: Yeah, me too.
12:16
Speaker 1: So we were talking about how cancer cells grow uncontrollably,
12:20
Speaker 1: but that's not enough to be a cancer cell, right
12:22
Speaker 1: Just because you change the gene it controls replication doesn't
12:25
Speaker 1: make you already cancer. It's because the cell can just die, right,
12:29
Speaker 1: So in order to have cancer, you need to have
12:31
Speaker 1: uncontrolled replication, and you need to break this apoptosis. This
12:35
Speaker 1: thing that tells the cell to turn itself off because
12:37
Speaker 1: you're done, buddy, needs to also break and so you
12:40
Speaker 1: have to have uncontrolled replication and the cell has to
12:43
Speaker 1: be immortal. This is what I meant earlier when I said, like,
12:46
Speaker 1: you require multiple mistakes in the cell, from like happy
12:50
Speaker 1: cell that's growing nicely and playing kindly with everybody, to
12:53
Speaker 1: cancer cell that's going to grow uncontrollably, making more of
12:57
Speaker 1: itself and refusing to die off.
12:59
Speaker 3: Yeah, feeding itself, managing to get more blood vessels to
13:02
Speaker 3: be made to feed those cells and stuff, and then
13:05
Speaker 3: it starts choking off other things. And yeah, thinking about
13:08
Speaker 3: all the different ways our bodies can break down, it's
13:10
Speaker 3: amazing they ever do anything right. But Kelly's catastrophizing today.
13:16
Speaker 1: That is a terrifying rabbit hole to dig into. And
13:19
Speaker 1: I've done that sometimes, especially you know, when under the
13:22
Speaker 1: influence of various substances, and I'm like, wow, I am
13:25
Speaker 1: this pulsing, throbbing meat machine, And it's incredible that it
13:29
Speaker 1: just keeps working and for most people, just works for
13:33
Speaker 1: decades without lots of issues. It's amazing that it survives
13:37
Speaker 1: this long. On the other hand, of course, if it didn't,
13:39
Speaker 1: we wouldn't be here, and so obviously evolution has done
13:42
Speaker 1: its job.
13:43
Speaker 3: That's right, Well, we all made the wake up list today,
13:46
Speaker 3: so hurrah for all of us.
13:47
Speaker 1: Correct, what's the wake up list the people who didn't
13:50
Speaker 1: die in their sleep? That's dark? Well, oh my gosh.
13:56
Speaker 3: Yeah, that is what it means. So anyway, Well.
13:59
Speaker 1: Do you wake up every morning and you're like, ah,
14:01
Speaker 1: I was on today's wake up list?
14:03
Speaker 3: No, but I do wake up in the mornings and think,
14:05
Speaker 3: you know, you don't know how many days you've got,
14:07
Speaker 3: so you should try to make sure you're doing doing
14:09
Speaker 3: good by you and your family and your kids.
14:11
Speaker 1: But yeah, anyway, all right, So cancer is uncontrolled, constant growth.
14:16
Speaker 1: It builds these blood vessels, It SAPs the resources, and
14:20
Speaker 1: you might think, why do I care if I have
14:22
Speaker 1: a little blob of cells that are growing out of control. Well,
14:25
Speaker 1: you know, they're growing out of control, so they get
14:26
Speaker 1: bigger and bigger, right, And if it's like that's in
14:28
Speaker 1: your brain, it's going to press on important stuff like
14:31
Speaker 1: the things that control your balance or your memory or
14:35
Speaker 1: your speech patterns, and that's going to be an issue.
14:38
Speaker 1: Or if it's in your pancreas or if it's in
14:40
Speaker 1: your liver, right, it can impede the function of the
14:42
Speaker 1: normal cells. And also it can spread, right, that's the
14:46
Speaker 1: real danger. If you have cancer and it's just in
14:48
Speaker 1: one spot and you're like, Okay, I got to get
14:49
Speaker 1: this blob out, then they can just do surgery and
14:52
Speaker 1: cut it out, or they can do radiation like we're
14:54
Speaker 1: going to talk about. But the time that cancer really
14:56
Speaker 1: becomes deadly is when it spreads to the rest of
14:58
Speaker 1: your body. And this is what means pastasis. Is usually
15:02
Speaker 1: it spreads into the bloodstream and then the blood carries
15:05
Speaker 1: it all around the body and it lodges somewhere and
15:07
Speaker 1: then it keeps doing its cancer thing. And now instead
15:10
Speaker 1: of having one blob that's growing out of control that
15:12
Speaker 1: you can maybe deal with, you have lots of them,
15:15
Speaker 1: uncountable number, and they're also spreading, and so very quickly
15:18
Speaker 1: it goes out of control. So often it's crucial to
15:21
Speaker 1: catch cancer early before it metastasizes.
15:24
Speaker 3: Future casting here, I'm not going to be sleeping well
15:27
Speaker 3: tonight we're.
15:29
Speaker 1: Just doing a lot of ironic foreshadowing because we're going
15:31
Speaker 1: to get to the bit where we're carrying it. We
15:33
Speaker 1: just need to set it up, all right, So all right, great,
15:36
Speaker 1: But this is not a small issue, right. Cancer is
15:38
Speaker 1: a real killer. Yeah, three percent of people in the
15:41
Speaker 1: United States are cancer survivors. It's a huge number. Cancer
15:46
Speaker 1: hits about one hundred million people a year, and there's
15:49
Speaker 1: like ten million deaths a year. So like, this is
15:53
Speaker 1: a real issue. You know, a huge fraction of our
15:55
Speaker 1: healthcare budget is focused on cancer, as it should be.
15:58
Speaker 1: This is what motivated like Joe Biden's cancer moonshot, Like, hey,
16:02
Speaker 1: can we crack this thing? But as you were saying earlier,
16:05
Speaker 1: one of the big struggles with dealing with cancer is
16:08
Speaker 1: that it's not just cancer. It's cancers. Is like more
16:12
Speaker 1: than one hundred different types of cancer, and they come
16:15
Speaker 1: in all kinds of varieties. Like a huge fraction of
16:17
Speaker 1: them are just caused by tobacco use, Like twenty percent
16:20
Speaker 1: of all cancer is like from smoking or some kind
16:24
Speaker 1: of like snorting, their sniffing, their sucking on those leaves.
16:27
Speaker 1: But there's another chunk like twenty percent that are due
16:30
Speaker 1: to infection like some virus comes in and injects its
16:34
Speaker 1: DNA into your cells, and now those cells are cancerous
16:37
Speaker 1: because they've changed your cells in exactly the right way
16:39
Speaker 1: to trigger that cancer.
16:41
Speaker 3: Jerks, jerks.
16:42
Speaker 1: But the good news is, like we know how to
16:43
Speaker 1: deal with viruses, so now we have like vaccines against cancer.
16:47
Speaker 3: That's amazing, right, yes, incredibly cool.
16:51
Speaker 1: Like cervical cancer caused by the human papilloma virus, Like
16:54
Speaker 1: we have really treated that and really the rates of
16:57
Speaker 1: that cancer have dropped tremendously, so they're real here. Even
17:01
Speaker 1: though it's lots of different kinds of cancers which require
17:04
Speaker 1: lots of different kinds of approaches, people are working hard
17:07
Speaker 1: on this and really making progress. So you know, go
17:09
Speaker 1: big pharma, go mds, Like, thank you to all those
17:12
Speaker 1: folks working on the front line and saving those lives.
17:15
Speaker 3: Amen. And also, you know, to focus a little bit
17:17
Speaker 3: more on silver lining. You know, the reason so many
17:20
Speaker 3: of us are getting cancer and having cardiovascular problems these
17:23
Speaker 3: days is because a lot of us are living to
17:25
Speaker 3: be old enough for this kind of stuff to become
17:27
Speaker 3: a problem. You know, before there's a pretty good chance
17:30
Speaker 3: you wouldn't survive to be five, But now a lot
17:32
Speaker 3: of us, you know, live a lot longer.
17:34
Speaker 1: And cancer doesn't just strike humans. You know. One of
17:37
Speaker 1: the main reasons that rats die, for example, is that
17:39
Speaker 1: they live long enough if they're well fed, yeah, to
17:42
Speaker 1: get cancer. We had pet rats and after a couple
17:44
Speaker 1: of years, they each got these big tumors that were
17:47
Speaker 1: like dragging these things around, like these big blobs hanging
17:51
Speaker 1: off their bellies. And Katrina has a good friend who
17:54
Speaker 1: does cancer studies on rats, and she knows how to
17:58
Speaker 1: operate to remove tumors, and so she offered to operate
18:01
Speaker 1: on our rats. And I was like, yeah, I don't
18:04
Speaker 1: know if we need to bring our rats into your
18:06
Speaker 1: like special expensive facilities. Like at some point, you know,
18:10
Speaker 1: you're just fighting a losing battle. You cut these tumors out,
18:12
Speaker 1: you know there are more coming. But it was sad.
18:15
Speaker 1: You know. Rats are wonderful little critters. Yeah, and they
18:18
Speaker 1: don't live very long, and we bonded with them. But
18:20
Speaker 1: on the flip side, that's when we decided we needed
18:22
Speaker 1: a longer living critter. And now we have a dog.
18:25
Speaker 3: Oh that's fantastic.
18:26
Speaker 1: Yeah, but you're right, the bigger picture is as we
18:30
Speaker 1: live longer, as we tackle these things, we just discover
18:32
Speaker 1: new things that were going to kill us. Right, the
18:34
Speaker 1: front just moves and we have a new battle to fight.
18:37
Speaker 3: That's right, and it's time to take a break. And
18:39
Speaker 3: when we get back, we're going to talk about why
18:41
Speaker 3: sharks don't get cancer, and we're back. That was a
19:05
Speaker 3: trick setup, because even though you hear over and over
19:07
Speaker 3: again the sharks don't get cancer, sharks do get cancer.
19:11
Speaker 1: Gotcha, what, Kelly, are you dispelling another pop sign? Myth? Yeah?
19:16
Speaker 3: Sorry?
19:16
Speaker 1: So why was it so commonly said that sharks don't
19:19
Speaker 1: get cancer? Was that just purely invented or is it,
19:21
Speaker 1: like a crab study, a misunderstanding of real science.
19:25
Speaker 2: I don't know.
19:25
Speaker 3: It could be both. I mean, I imagine that a
19:27
Speaker 3: lot of times when animals in the wild get cancer,
19:29
Speaker 3: it debilitates them to the point where something else gets them,
19:33
Speaker 3: you know, a predator eats them, for example. And so
19:36
Speaker 3: it just could be that we didn't encounter many sharks
19:39
Speaker 3: that had tumors, or people who did noted it but
19:42
Speaker 3: didn't you know, publish on it or something. And so
19:44
Speaker 3: I don't know, somehow this misconception entered its way into
19:48
Speaker 3: the twitter sphere or the exosphere whatever. We call it now,
19:51
Speaker 3: but anyway, yes, sharks get cancer.
19:55
Speaker 1: The exosphere is actually a science word already. It's like
19:59
Speaker 1: when you don't have an atmosphere, you have particles that
20:02
Speaker 1: are just flying around, not interacting with each other. Like
20:04
Speaker 1: the moon has no atmosphere, but it does have an exosphere,
20:07
Speaker 1: even though there's nobody on the moon posting on X.
20:10
Speaker 3: But that's spelled exo, right, yeah, so this would be
20:13
Speaker 3: like the xh O sphere or something.
20:17
Speaker 1: You can't have two words that sound exactly the same.
20:20
Speaker 1: Oh my god.
20:20
Speaker 3: I mean, you know, the English language is the worst
20:23
Speaker 3: in terms of us spelling of stuff.
20:24
Speaker 1: So the particle beams can't cure the problem of the
20:27
Speaker 1: English language, but maybe they can help with cancer. So
20:30
Speaker 1: let's lower our sights and think about that instead.
20:32
Speaker 3: So let's overview some of the ways that we can
20:34
Speaker 3: deal with cancer.
20:35
Speaker 1: So, if you have cancer, your options are often surgery.
20:38
Speaker 1: Like if it's localized, it hasn't spread, and it's not
20:41
Speaker 1: next to something else really really delicate, then off you
20:44
Speaker 1: can cut it out, Like if you have skin cancer,
20:47
Speaker 1: they can just clip that thing off because you don't
20:49
Speaker 1: need to go inside the body, it's not next to
20:51
Speaker 1: anything else dangerous. And it's probably hopefully hasn't spread yet,
20:55
Speaker 1: and so they can just cut it off. Whereas if
20:58
Speaker 1: you have, for example, something growing inside your brain, surgery
21:01
Speaker 1: is more complicated because they've got to go into your
21:02
Speaker 1: brain and maybe it's touching something else really delicate, and
21:06
Speaker 1: it's hard for the surgeon to cut out the whole
21:09
Speaker 1: thing without touching that delicate nerve and maybe impacting your
21:13
Speaker 1: brain function. Right, that was the great fear for my
21:16
Speaker 1: two friends who recently had brain surgery because of growth.
21:19
Speaker 3: You had two friends who had brain surgery. Are they
21:21
Speaker 3: both doing okay?
21:22
Speaker 1: Both of them are fine, Both of them are scientists,
21:24
Speaker 1: and both of them were back to work amazingly just
21:26
Speaker 1: like a month after brain surgery. So it's incredible what
21:30
Speaker 1: modern medicine can do. Ten hour surgery got to cut
21:33
Speaker 1: out these lumps, and yeah, they're back to work and
21:36
Speaker 1: making the same terrible dad jokes ever email that they
21:39
Speaker 1: were before surgery. So I can't even blame it on
21:41
Speaker 1: the cancer.
21:43
Speaker 3: My daughter is really into puppeteering, and her hero Adam
21:46
Speaker 3: Krutinger passed away from a brain tumor recently, and so
21:50
Speaker 3: these are difficult things to tackle.
21:52
Speaker 1: Yeah, it's scary, but you know, there's a lot of
21:54
Speaker 1: people working hard and dedicating their lives to making this better.
21:57
Speaker 1: So surgery is a great option if it's still localize
22:00
Speaker 1: and it's not close to anything else that you're risking.
22:04
Speaker 1: Another option, of course, is chemotherapy, and we kind of
22:06
Speaker 1: a whole episode on that if you like. But essentially
22:09
Speaker 1: you're just drinking poison, yeah, and you're hoping the poison
22:12
Speaker 1: kills the cancer, or the poison is designed by clever
22:14
Speaker 1: chemists to kill the cancer faster than it kills you,
22:19
Speaker 1: and so it's a race of attrition there.
22:20
Speaker 3: Yeah. As I understand it, cancer cells tend to replicate
22:23
Speaker 3: faster than other things, and so it's targeting very quickly
22:27
Speaker 3: replicating cells. And that's partly why you lose your hair,
22:31
Speaker 3: because you've got like very fast replication happening in those
22:34
Speaker 3: follicles and they kind of get shut down for a
22:36
Speaker 3: little while, so your hair falls out. And actually, we
22:38
Speaker 3: should get someone who knows what they're talking about, because
22:41
Speaker 3: I'm just vaguely remembering these facts and they could be wrong,
22:45
Speaker 3: but you're.
22:46
Speaker 1: Right in each case. What we're trying to do is
22:49
Speaker 1: highlight a particularly sensitivity to cancer and then take advantage
22:53
Speaker 1: of that in our attack, and the same thing is
22:55
Speaker 1: going to be true for radiotherapy, which is particle therapy,
22:58
Speaker 1: and we're shooting beams at the cancer. The idea is
23:02
Speaker 1: that these cancer cells have a mutation in the place
23:06
Speaker 1: where they're doing their DNA replication right when they're replicating,
23:09
Speaker 1: instead of doing a normal rate, they're doing an uncontrolled rate.
23:13
Speaker 1: And so these cells are actually pretty bad at repairing damage. Right,
23:18
Speaker 1: They're already damaged, and they're worse than normal cells at
23:21
Speaker 1: repairing damage. And so if you attack them and try
23:24
Speaker 1: to break up their DNA, they are more sensitive to
23:27
Speaker 1: those kind of attacks than normal cells.
23:30
Speaker 3: Ah okay, but so you told us that they're also
23:33
Speaker 3: resistant to apoptosis, so resistant to breaking apart. Is the
23:37
Speaker 3: idea just that if you mess up the DNA enough,
23:40
Speaker 3: they just kind of like die and wither away.
23:42
Speaker 1: Yeah, okay, hmm exactly. I asked Katrina about this actually,
23:45
Speaker 1: and she said, another way to look at a crazy
23:48
Speaker 1: cancer cell is that it's less resilient. It has all
23:50
Speaker 1: these broken repair mechanisms that makes it easier to take down.
23:54
Speaker 1: And so if you can shatter its DNA or attack
23:57
Speaker 1: its DNA, it's less likely to be able to to survive,
24:01
Speaker 1: so they're more fragile in that sense, they're more susceptible
24:04
Speaker 1: to radiation than the normal cell.
24:06
Speaker 3: Okay, but chemotherapy often acts throughout your body, and it
24:09
Speaker 3: would be really nice to be able to target so
24:11
Speaker 3: you don't get negative impacts spread throughout the body. And
24:14
Speaker 3: so particle therapy, I'm guessing, can give us that.
24:17
Speaker 1: Yes, exactly. Particle therapy is not just like broadly shooting
24:22
Speaker 1: radiation at your whole body. We're shooting particles in a
24:24
Speaker 1: very narrow beam, so we can aim where it goes.
24:27
Speaker 1: If you have a tumor in your brain, we're not
24:30
Speaker 1: shooting particle beams into your toes, and we can get
24:33
Speaker 1: very very precise with it. And you can think about
24:35
Speaker 1: it in three dimensions as well, because imagine you have
24:38
Speaker 1: a tumor in your brain somewhere right the goal is
24:40
Speaker 1: to have the particles hit the tumor and nothing else
24:43
Speaker 1: that would be ideal. Right now, we can't do that perfectly.
24:47
Speaker 1: We have to shoot it through some normal tissue to
24:49
Speaker 1: get it to the tumor. So we have a few
24:52
Speaker 1: ways to avoid damaging the normal cells along the way,
24:56
Speaker 1: and we're going to talk about one of them being
24:58
Speaker 1: particle choice, but the other one very simple, which is
25:01
Speaker 1: that you just shoot from a few different angles and
25:03
Speaker 1: those beams intersect at the tumor, so the beams aren't
25:07
Speaker 1: going to hit some normal cells, but the normal cells
25:09
Speaker 1: all just get like one beam, but the tumor gets
25:11
Speaker 1: like four beams. Or the generalization of this is that
25:14
Speaker 1: you have a single beam that sweeps around you, and
25:17
Speaker 1: as it rotates, it's consistently on the tumor, but the
25:21
Speaker 1: normal cells are only getting it part of the time.
25:23
Speaker 1: So the tumor gets it constantly and it spreads out
25:27
Speaker 1: the beam across a bunch of other normal cells, so
25:29
Speaker 1: they thee is to deposit more energy to do more
25:31
Speaker 1: damage on the tumor cells than on the normal cells.
25:35
Speaker 1: And so the way you do that is by shooting
25:36
Speaker 1: from multiple angles or by scanning around, so the beam
25:40
Speaker 1: stays constantly on the tumor but is spread around on
25:43
Speaker 1: the normal cells. Does that make sense?
25:45
Speaker 3: That does? Yeah. So I've talked to a few friends
25:46
Speaker 3: who have had cancer and the treatment that they got
25:50
Speaker 3: saved their lives but increased their future risk of getting
25:54
Speaker 3: cancer because it damaged the DNA of some of their
25:56
Speaker 3: other cells. Do we know for this treatment when you
25:59
Speaker 3: get I don't think I would love the idea of
26:01
Speaker 3: having particles go through all of my brain, even if
26:04
Speaker 3: I knew they were still focused on one spot. But
26:06
Speaker 3: you know, it still sounds better than the alternative of
26:08
Speaker 3: letting the tumor grow. But do we know with this
26:11
Speaker 3: method forty years down the road, does it increase your
26:13
Speaker 3: probability of getting a tumor somewhere else?
26:16
Speaker 1: It definitely increases your probability of getting a tumor in
26:19
Speaker 1: that otherwise normal tissue, because you're shooting beams through it,
26:22
Speaker 1: and you're depositing energy and you're damaging DNA, and so yeah,
26:25
Speaker 1: you're setting yourself up for cancer in those cells. But
26:28
Speaker 1: people are trying to make this more and more accurate
26:31
Speaker 1: by controlling the dose, by doing really thin scans, by
26:35
Speaker 1: making sure that the dose is like the minimal necessary.
26:38
Speaker 1: People used to have really high doses to make sure
26:41
Speaker 1: they got the tumor, and now they can scale that
26:44
Speaker 1: down and have better models for calculating the dose. They
26:46
Speaker 1: just used to assume, like the human body is water.
26:48
Speaker 1: Now they're like, okay, well there's other tissues in there,
26:50
Speaker 1: and we need to take that into account. Think about
26:52
Speaker 1: the scattering, you know, and now they think more about
26:55
Speaker 1: the angles, what is it going to go through. As
26:57
Speaker 1: time goes on, we get better and better at this,
27:00
Speaker 1: and also crucially, we're choosing the particles we shoot because
27:04
Speaker 1: that can determine where the energy lands.
27:06
Speaker 3: Okay, so let's talk about what our options are for particles.
27:09
Speaker 1: Yeah, so number one is photons. Right, We all get
27:13
Speaker 1: radiation when we go to the doctor for a broken bone.
27:16
Speaker 1: They use X rays to take a picture of your insides.
27:20
Speaker 1: And X rays pass through the body, but they're absorbed
27:23
Speaker 1: differently by bones and by soft tissue, and that's why
27:26
Speaker 1: you can see through the body. Right, And this is
27:28
Speaker 1: a whole fascinating topic here about transparency, like why can
27:32
Speaker 1: visible light not go through the body but X rays can.
27:35
Speaker 1: The answer is that for photons, how far they go
27:38
Speaker 1: through and where they deposit their energy or if they
27:40
Speaker 1: do deposit their energy, depends on the wavelength of light. Today,
27:45
Speaker 1: we're just going to talk about that interchangeably. Right, Radiation
27:47
Speaker 1: is made of particles. One example is a photon. We'll
27:50
Speaker 1: also talk about electrons and protons, but we'll start with
27:53
Speaker 1: photons mostly X rays.
27:54
Speaker 3: I feel like I'm still not really understanding how X
27:56
Speaker 3: rays work. Can you give me some more detail.
27:59
Speaker 1: Let's think about what happens when a photon hits your body, right,
28:03
Speaker 1: And let's say, for example, it's a normal visual light photon,
28:06
Speaker 1: like a red photon that's just flying around. Well, what
28:10
Speaker 1: happens when it hits your body is it finds a
28:12
Speaker 1: bunch of atoms, and those atoms all have energy levels. Right,
28:15
Speaker 1: there are electrons whizzing around those atoms, and they can
28:18
Speaker 1: absorb some photons. If an electron has an energy level
28:22
Speaker 1: that matches the energy of the photon that's coming in,
28:25
Speaker 1: it can eat it. Like if the electron is an
28:27
Speaker 1: energy level five and it needs a certain amount of
28:29
Speaker 1: energy to go up to six or to seven, and
28:31
Speaker 1: a photon comes along with just that much energy, boom,
28:34
Speaker 1: it can gobble it up. So this is atomic absorption
28:37
Speaker 1: and also atomic emission. Like we talked about recently in
28:40
Speaker 1: our episodes about what color is the sun, that same atom,
28:43
Speaker 1: if the electron is in the higher energy level, it
28:46
Speaker 1: can release that energy shooting off that photon. So atoms
28:49
Speaker 1: can absorb photons of specific energy levels. Right. This is
28:53
Speaker 1: why red paint is red, right, because it absorbs everything.
28:56
Speaker 1: But the red reflects the red. The red doesn't get
28:59
Speaker 1: absorbed by those materials. This is why glass is transparent
29:03
Speaker 1: because there are no atoms in the glass that can
29:06
Speaker 1: drink light in the visible spectrum, right, so it just
29:08
Speaker 1: passes through. So for very low energy light, like the
29:11
Speaker 1: kind that's in the visible spectrum, whether or not it
29:14
Speaker 1: goes through or whether or not it's absorbed in, deposits
29:17
Speaker 1: its energy. And that's the crucial thing, right for curing
29:19
Speaker 1: cancer or treating cancer, you want to deposit your energy
29:22
Speaker 1: depends precisely on what energy you have. But for treating cancer,
29:26
Speaker 1: we're not normally shooting just like light bulbs at people, right,
29:29
Speaker 1: We're shooting higher energy stuff. And so at higher energy
29:33
Speaker 1: what happens is the photoelectric effect. Instead of the electron
29:36
Speaker 1: just going up an energy level, you kick the electron
29:39
Speaker 1: off of the atom, right, You completely ionize it. So
29:42
Speaker 1: if you have high enough energy like X rays for example,
29:45
Speaker 1: they can kick electrons out of the atom. This is
29:48
Speaker 1: the photoelectric effect that Einstein used to like discover quantum
29:52
Speaker 1: mechanics and all that kind of stuff. And then at
29:54
Speaker 1: even higher energy levels, what happens to a photon is
29:58
Speaker 1: that it pair produces it turns to an electron and
30:01
Speaker 1: a positron because of the nuclear electric field, and so
30:05
Speaker 1: what happens to a photon depends a lot on its
30:07
Speaker 1: energy relative to the matter. And so X rays are
30:11
Speaker 1: a typical thing that we use in radiotherapy, and they
30:14
Speaker 1: do penetrate, right, and so they have high energy, so
30:17
Speaker 1: they can get pretty deep into your body. Like if
30:19
Speaker 1: you just shoot red light at somebody, it's absorbed at
30:21
Speaker 1: the skin, but X rays can penetrate, they can go
30:24
Speaker 1: further in. The downside of X rays for treatment is
30:27
Speaker 1: that they leave a lot of energy in the first
30:29
Speaker 1: few layers, like they deposit energy and then they sort
30:32
Speaker 1: of peter out, and so a lot of the energy
30:34
Speaker 1: is deposited near the top. So if you want to
30:36
Speaker 1: get like deeper in you have like a tumor like
30:38
Speaker 1: three centimeters under the skin, you have to shoot a
30:40
Speaker 1: lot of X rays at it, and the normal cells,
30:43
Speaker 1: the cells you don't want to treat that are between
30:46
Speaker 1: the skin and the tumor are also getting a lot
30:48
Speaker 1: of X ray energy. So that's why for X rays
30:50
Speaker 1: it's crucial to like rotate it around the body.
30:53
Speaker 3: And so when you go to get an X ray
30:55
Speaker 3: and you wear a lead. Oh, that lead is not
30:58
Speaker 3: covering the spot where you're getting the X rays, ring
31:00
Speaker 3: everything else, got it?
31:01
Speaker 1: Okay, yeah, exactly, it's covering your critical bits. Yeah. Because
31:05
Speaker 1: X ray penetration also depends on the atomic nucleus, right.
31:09
Speaker 1: If the atom has high Z a lot of protons
31:11
Speaker 1: and neutrons in the nucleus, then it's likely to absorb
31:15
Speaker 1: the X rays rather than let them through, and so
31:16
Speaker 1: the lead is like a shield for you.
31:18
Speaker 2: Got it.
31:18
Speaker 3: I really messed up my ankle when I was pregnant,
31:22
Speaker 3: and I was so worried to get an X ray. Uh,
31:25
Speaker 3: you know, I didn't want to hurt little Ada. But anyway,
31:27
Speaker 3: she was fine thanks to the lead blanket. Or maybe
31:30
Speaker 3: she's weird because something went wrong, but she's weird in
31:34
Speaker 3: the best way possible.
31:35
Speaker 1: So anyway, Well, they used to take X rays with
31:37
Speaker 1: incredibly bright sources, right, and now they've reduced those X
31:41
Speaker 1: rays far as they can and they can still see
31:43
Speaker 1: inside your body, but with much much lower luminosity. They've
31:46
Speaker 1: improved the detectors they put on the other side, so
31:49
Speaker 1: X rays are much safer than they used to be.
31:52
Speaker 1: If you're going to get an X ray in like
31:53
Speaker 1: the fifties or sixties. Can you're really dangerous, but now
31:57
Speaker 1: it's much much safer. Yeah, the get do not deliver
32:01
Speaker 1: a dangerous amount of radiation. And there are other things
32:03
Speaker 1: we do in our lives, like fly on an airplane,
32:06
Speaker 1: that do increase our radiation dose. But people don't really
32:08
Speaker 1: think about it that way very much.
32:10
Speaker 3: No, I don't, but I'm about to go on a
32:11
Speaker 3: long plane ride. Thanks for ruining it for me.
32:14
Speaker 1: One more thing to worry about.
32:16
Speaker 3: That's right. Oh man, I just sleeps so good tonight. Okay,
32:19
Speaker 3: So how do we make these X ray beams? Daniel?
32:22
Speaker 1: Yeah, exactly. If you want to make a beam of
32:25
Speaker 1: red light, you just like heat of a tungsten filament
32:27
Speaker 1: and it glows in the white and you can have
32:29
Speaker 1: like a prism and filter out the red light. But
32:31
Speaker 1: if you want X ray beams, we don't have stuff
32:34
Speaker 1: that glows in the X ray. You need like super
32:36
Speaker 1: duper crazy hot gas. Like sources of X rays astrophysically
32:40
Speaker 1: come from like gas near black holes and stuff, and
32:43
Speaker 1: so we don't have that here. It's not easy to generate.
32:46
Speaker 1: So instead, what you just do is you just heat
32:48
Speaker 1: up the electrons, right, take a bunch of electrons, speed
32:51
Speaker 1: them up using an electric field. Electrons respond to electric fields,
32:54
Speaker 1: so they're going really really fast. This is a lot
32:57
Speaker 1: like what we do in particle physics, and then bend
33:00
Speaker 1: them with a magnet. Do you have an electron super
33:02
Speaker 1: high velocity going in some direction it encounter as a
33:05
Speaker 1: magnetic field was to do it? Bends? Right, And when
33:08
Speaker 1: an electron bends, the only way you can do it
33:11
Speaker 1: is by emitting a photon. Right. That's how electrons bend,
33:15
Speaker 1: and in a sense, it's interacting with the electromagnetic field,
33:18
Speaker 1: and so photons are a natural way for that to
33:20
Speaker 1: do it. And so when it's going at high speed
33:23
Speaker 1: and bends through a magnet, it tends to emit a
33:24
Speaker 1: high energy photon and that's our source of X rays,
33:28
Speaker 1: which is why you often have like X ray crystallography
33:31
Speaker 1: facilities at places with particle beams, like an Argone National Lab,
33:34
Speaker 1: they have like a world class X ray crystallography set
33:37
Speaker 1: up because they're also good at particles cool.
33:40
Speaker 3: Okay, so this sounds like a really great method for
33:42
Speaker 3: creating X rays and finding where tumors are, But this
33:45
Speaker 3: is not something you'd ever use to treat a tumor.
33:47
Speaker 1: Right, Well, you can use these to treat tumor. They're
33:50
Speaker 1: not great because they, as we said before, they pass
33:53
Speaker 1: through the body and they deliver energy in many layers.
33:55
Speaker 1: But you can use X rays, you can use high
33:57
Speaker 1: energy photons to treat a tumor. So these days we
34:00
Speaker 1: have more advanced techniques than are superior.
34:03
Speaker 3: Yeah, okay, so we were just talking about electrons. Can
34:06
Speaker 3: you skip the phase where you use a magnet to
34:08
Speaker 3: get X rays and just use those electrons directly?
34:11
Speaker 1: You can use electrons and shoot them at people, right,
34:14
Speaker 1: and they will deliver their energy. But electrons are not
34:16
Speaker 1: very penetrating. Right, Your skin mostly stops electrons. At very
34:21
Speaker 1: low energy, the electron will just like ionize atoms and
34:24
Speaker 1: be absorbed. At very high energy, the electrons will emit
34:27
Speaker 1: a bunch of radiation and slow down. It's called bremstrong lung,
34:31
Speaker 1: which is German for like breaking radiation. And so electrons
34:35
Speaker 1: are not very penetrating, mostly because they're very very low mass,
34:38
Speaker 1: and so like any interaction basically stops them because even
34:42
Speaker 1: at high energy, they don't have a lot of momentum
34:44
Speaker 1: because their mass is so low, and so they're not
34:47
Speaker 1: a great choice for penetrating the gold standard. The thing
34:49
Speaker 1: you really want is some kind of radiation which takes
34:52
Speaker 1: a while to stop, which like flies through your body
34:55
Speaker 1: and then deposits its energy all in one go somewhere
34:59
Speaker 1: deep in your body in a way that you can tune.
35:02
Speaker 3: And so we've talked about photons and electrons, and let's
35:05
Speaker 3: let the listeners guess what kind of particle it is
35:08
Speaker 3: that does that, and we'll get back to it after
35:11
Speaker 3: the break. All right, So we've already talked about photons,
35:33
Speaker 3: we've already talked about electrons, but the best method is
35:36
Speaker 3: one we haven't talked about yet. And by process of elimination,
35:39
Speaker 3: I'm gonna guess.
35:40
Speaker 1: It's protons because you only have three particles in your mind,
35:44
Speaker 1: that one.
35:45
Speaker 3: Well, you know, you told new particles are complicated, But yes,
35:50
Speaker 3: I guess those are the first three that come to mind.
35:52
Speaker 1: Well, that's fair because the universe is mostly made of protons, electrons,
35:56
Speaker 1: and photons. So that's a good set to have in
35:58
Speaker 1: your mind. Good choice, Kelly.
36:00
Speaker 3: I also have this outline in front of me that
36:03
Speaker 3: says protons.
36:04
Speaker 1: Next, So that makes you sound smart.
36:06
Speaker 3: That's right. That's my trick.
36:09
Speaker 1: Protons are a great choice for treating cancer, and protons
36:12
Speaker 1: are also one of the favorite toys of particle physicists
36:15
Speaker 1: because we can accelerate them to really high energies and
36:18
Speaker 1: bend them around. They have a lot of mass compared
36:20
Speaker 1: to an electron, so you can get them going really fast,
36:23
Speaker 1: and when they go around curves, they don't emit as
36:25
Speaker 1: much radiation because they're heavier, and protons, because of the
36:29
Speaker 1: way they interact with matter, can penetrate deeply and deposit
36:32
Speaker 1: their energy deep under the skin without harming as much
36:37
Speaker 1: the tissue in between.
36:38
Speaker 3: Oh that's fantastic. Yeah, why does it work that way?
36:41
Speaker 1: Yeah, it's fascinating. Protons can interact with the electrons and
36:45
Speaker 1: matter right or with the nucleus, and which one they
36:49
Speaker 1: do depends on their velocity. So when they're going really fast,
36:53
Speaker 1: they basically can't see the nucleus and they just interact
36:56
Speaker 1: with the electrons. But it's like glancing collisions. It's too
36:59
Speaker 1: big and heavy to really get slowed down by these electrons.
37:02
Speaker 1: It's like a bulldozer are going through a field of snowmen. Right,
37:05
Speaker 1: It's just like plows right through them hardly, gets hardly
37:08
Speaker 1: gets slowed down. Just reading Calvin and Hobbes and so
37:13
Speaker 1: perfect and so like each snowman that the bulldozer hit
37:16
Speaker 1: slows down a tiny little bit, but it really doesn't
37:18
Speaker 1: deposit a lot of energy. It doesn't get slowed down.
37:21
Speaker 1: But this interaction is dependent on the velocity squared, and
37:24
Speaker 1: so at some point it reaches some threshold where it
37:26
Speaker 1: does get slowed down enough. Now it's going to interact
37:29
Speaker 1: with the atomic nucleus and that is going to rapidly
37:32
Speaker 1: sap it of energy. And so there's like a threshold
37:35
Speaker 1: there above which it can mostly ignore what's going on
37:37
Speaker 1: inside the nucleus and just plow on forward. But when
37:40
Speaker 1: it gets too slow, then all of a sudden, it's
37:43
Speaker 1: a very strong interaction with a nucleus and it deposits
37:46
Speaker 1: a lot of its energy right there. And so that's
37:48
Speaker 1: why it's excellent of course for treatment. And this is
37:50
Speaker 1: called the brag peak.
37:52
Speaker 3: I remember reading about the brag peak because when I
37:55
Speaker 3: was reading about space radiation. One of the problems with
37:59
Speaker 3: trying to understand and how radiation impacts people is that
38:02
Speaker 3: you often study it in rodents yea. And rodents are
38:06
Speaker 3: just smaller than humans. There's less mass that the proton
38:10
Speaker 3: needs to go through and if the particles in some
38:13
Speaker 3: cases are just like shooting through the rats, then you
38:15
Speaker 3: don't really understand the impact of the radiation because the
38:18
Speaker 3: particle didn't stop and release all of its energy inside
38:21
Speaker 3: of the body of the organism. And so there's some
38:24
Speaker 3: concern that, like studying rodents, doesn't tell you exactly what
38:27
Speaker 3: you need to know because humans are just bigger, and
38:30
Speaker 3: we're more likely to stop a particle because it's running
38:32
Speaker 3: into more stuff. Does that make sense?
38:34
Speaker 1: Yeah, that makes perfect sense. Can't you solve that problem
38:36
Speaker 1: just by like, you know, gluing a bunch of rats
38:38
Speaker 1: together into like a huge sphere of rat and then
38:41
Speaker 1: you could have enough rat to stop the protons.
38:43
Speaker 3: Daniel, you missed your calling in biology.
38:46
Speaker 1: I'm sure we could get that past the IRB, right,
38:48
Speaker 1: I don't see any problems with that.
38:50
Speaker 3: That sounds totally ethical. I'm sure that have high quality
38:53
Speaker 3: of life.
38:54
Speaker 1: I wonder if you need to have the mouths, I'll
38:55
Speaker 1: point it out, but then you know what's going on
38:58
Speaker 1: in the inside. Yeah, anyway, this problem not a great idea.
39:00
Speaker 3: This gets.
39:03
Speaker 1: So the brag peak is a great way to understand
39:05
Speaker 1: where the energy is deposited. By these various particles. So
39:09
Speaker 1: if you imagine like we're talking about as a function
39:11
Speaker 1: of the depth, how deep into the tissue. Start out
39:13
Speaker 1: with electrons mostly deposit energy the very surface. Photons deposit
39:18
Speaker 1: a lot of their energy the surface, then it fades gradually,
39:21
Speaker 1: but protons like deposit almost no energy, and then all
39:25
Speaker 1: of a sudden boom, you're like ten centimeters in. They
39:27
Speaker 1: deposit almost all of their energy there. That's the peak
39:29
Speaker 1: that they're referring to when they say the brag peak.
39:32
Speaker 1: And this is excellent, right, because if you could tune this,
39:34
Speaker 1: if you could say, oh, I wanted ten centimeters in
39:37
Speaker 1: or fifteen centimeters in, then you could basically just shoot
39:40
Speaker 1: a beam and have a deposit most of its energy
39:42
Speaker 1: deep within the tissue and spare the normal tissue where
39:45
Speaker 1: the protons are passing through. They're still plowing through those
39:48
Speaker 1: electronic snowmen, but they're not really doing a lot of damage.
39:52
Speaker 3: That's amazing, right, So tell me, in a practical sense,
39:54
Speaker 3: how would you do this?
39:55
Speaker 1: Yeah, so why changing the energy of the protons. You
39:58
Speaker 1: can change the depth, so where it deposit its energy
40:01
Speaker 1: depends on the velocity. Right, So if you start out
40:03
Speaker 1: with a lot of velocity. Then you're going to go
40:05
Speaker 1: much deeper and then all of a sudden deposit your energy.
40:08
Speaker 1: If you're very close to that threshold already, then you're
40:11
Speaker 1: not going to go very far and then cross over
40:13
Speaker 1: that threshold where you're depositing your energy. So you can
40:16
Speaker 1: tune the depth where the protons are depositing their energy,
40:19
Speaker 1: which means doing damage to those cells, breaking up the
40:22
Speaker 1: cancer DNA by tuning the energy of the protons. So
40:26
Speaker 1: you already have like two dimensional pointing just by pointing
40:29
Speaker 1: the beam at something. Right, now you have the third
40:32
Speaker 1: dimension of control. By tuning the energy of the beam,
40:35
Speaker 1: you can go deeper, you can go less deep, and
40:38
Speaker 1: so you can do this three D they call it
40:40
Speaker 1: tensile beam scanning, where you're changing the direction of it
40:44
Speaker 1: and you're changing its energy simultaneously, so you can trace
40:47
Speaker 1: out the three dimensional shape of the tumor. Right, you're
40:51
Speaker 1: probably imagining a tumor as a sphere, and that's what
40:53
Speaker 1: a physicists would do, and that's probably what they did
40:55
Speaker 1: twenty years ago, Like let's assume a spheertical tumor. But
40:59
Speaker 1: what that was clueless physicist accent I don't know.
41:04
Speaker 2: Was it German?
41:05
Speaker 3: That sounded vaguely?
41:07
Speaker 1: It was a rough average of all the accents I've
41:09
Speaker 1: heard it.
41:10
Speaker 3: Cern there you go, okay, perfect all there's.
41:12
Speaker 1: A little Russian in there, a little German, maybe, some Italian,
41:15
Speaker 1: and a smattering of Japanese. No, all right, I'm equally
41:19
Speaker 1: offending the whole world right now. But imagine if you
41:22
Speaker 1: can do a three D scan with like an MRI
41:24
Speaker 1: and you can see exactly where the tumor is, and
41:26
Speaker 1: tumors are never simply shaped, they're like long, and then
41:29
Speaker 1: they got a blob over here. And what you ideally
41:31
Speaker 1: want to do is deposit energy everywhere in the tumor
41:33
Speaker 1: and nowhere else. Well, with a proton beam, you can
41:36
Speaker 1: do that because you can aim the beam and then
41:39
Speaker 1: you can change the energy. You go back and forth
41:41
Speaker 1: and back and forth over the tumor. And then when
41:43
Speaker 1: you change the angle and now you're intersecting a different
41:46
Speaker 1: part of the tumor with a different shape and different depth,
41:48
Speaker 1: Now you change the energy the protons back and forth,
41:50
Speaker 1: back and forth. You can scan in three D. You
41:52
Speaker 1: can like trace out the whole tumor, use the brag
41:55
Speaker 1: peak to deposit energy there and almost nowhere else.
41:59
Speaker 3: That's amazing. So do we We have like complicated models
42:02
Speaker 3: that sort of figured that out ahead of time, and
42:03
Speaker 3: you just press a button and then it automatically gets
42:06
Speaker 3: the whole tumor, or is somebody like going, you know,
42:09
Speaker 3: step by step and like moving the beam around to
42:12
Speaker 3: get every little part of the tumor.
42:13
Speaker 1: It's all computerized, absolutely and controlled, so nobody's like, oops,
42:17
Speaker 1: I slipped and I you know, fried your eyeball or whatever.
42:22
Speaker 1: The disadvantage is that proton beams are harder, right, Like
42:25
Speaker 1: electron beams are easy to make electrons or light that
42:27
Speaker 1: you can accelerate them easily, X ray beams there's lots
42:30
Speaker 1: of ways to make that. Proton beams are complicated, and
42:33
Speaker 1: the magnets that bend them and point them are huge.
42:36
Speaker 1: We're talking like hundreds of tons of magnets usually wow.
42:41
Speaker 1: And so these facilities are much more specialized. Say sound fantastic,
42:44
Speaker 1: and if you get cancer, I hope you have access
42:47
Speaker 1: to one, But there are not that many of these
42:49
Speaker 1: facilities yet in the world because they are big and complicated.
42:53
Speaker 3: Is this also a kind of new treatment for cancer?
42:56
Speaker 3: How long has this been around?
42:57
Speaker 1: It's an idea that's been around since the forties. Like
43:00
Speaker 1: Robert Wilson, the guy who designed Fermilab and did all
43:03
Speaker 1: sorts of crazy architecture and it was a huge important
43:06
Speaker 1: particle physicist predicted this in the nineteen forties in a
43:09
Speaker 1: paper and it was first used in the fifties. It
43:12
Speaker 1: was pretty expensive until around twenty five years ago when
43:16
Speaker 1: people made some improvements in magnet technologies. Now, instead of
43:20
Speaker 1: there being like one center at Fermilab, for example, there
43:23
Speaker 1: are a few dozen centers worldwide, and as of like
43:27
Speaker 1: ten years ago, like one hundred thousand people had received
43:30
Speaker 1: this treatment. So it's still not the overwhelming treatment for cancer,
43:35
Speaker 1: mostly because there aren't that many centers and they're expensive,
43:39
Speaker 1: but it's definitely the best treatment you can get.
43:41
Speaker 3: So we're not medical doctors, so I just I want
43:45
Speaker 3: to clarify a little bit for the best treatment we
43:48
Speaker 3: can get. That probably depends on what kind of tumor
43:50
Speaker 3: you have. Yes, yeah, okay, So.
43:52
Speaker 1: From a particle physicist point of view, thinking about maximizing
43:56
Speaker 1: the control of the energy dose, proton beams are from
44:00
Speaker 1: physics point of view, the best way to optimize the
44:03
Speaker 1: energy dose delivered. But please speak to your doctor about
44:06
Speaker 1: your treatment needs. Don't listen to me.
44:08
Speaker 3: That's right, You're welcome, my heart. We had all the
44:10
Speaker 3: right caveats there.
44:14
Speaker 1: But for a particle physics nerd, it's very similar to
44:16
Speaker 1: what we do with the Large Adron Collider. Like how
44:18
Speaker 1: you make a proton beam, Well, that's what we have
44:20
Speaker 1: with the Large Adriene Collider is a proton beam, and
44:23
Speaker 1: so the steps are very similar. Like you start with hydrogen, right,
44:27
Speaker 1: protons are everywhere. Then the most common thing in the universe,
44:29
Speaker 1: the universe mostly hydrogen, which is a proton and an electron.
44:33
Speaker 1: Take some hydrogen, heat it up, so the electron goes
44:36
Speaker 1: away and you have protons, right, and then you just
44:39
Speaker 1: need to accelerate them, which means put them in an
44:41
Speaker 1: electric field. We used to just use flat electric fields
44:45
Speaker 1: to accelerate particles. Now we use these cool things called
44:47
Speaker 1: RF cavities. These things have oscillating electromagnetic waves, so the
44:51
Speaker 1: particles like surf on them, which is really cool, and
44:54
Speaker 1: get accelerated more easily over shorter distances to higher energies.
44:58
Speaker 1: And then you have magnets to keep them going in
45:00
Speaker 1: a loop. And that's exactly how the Large Hadron Collider
45:03
Speaker 1: works and so these are lower energy than the large
45:06
Speaker 1: hadron collider. You don't need crazy energies in order to
45:09
Speaker 1: deposit a dose in your brain. But it's the same technology.
45:13
Speaker 1: And so because it's more similar to the LAC than
45:15
Speaker 1: to like your standard technology, it is more specialized and
45:19
Speaker 1: it is more rare.
45:20
Speaker 3: All right, So let me tie this back to parasites.
45:22
Speaker 3: All right, So when you have a parasite in your
45:23
Speaker 3: body and then it dies, that can often be worse
45:27
Speaker 3: than having a live parasite in your body, because now
45:29
Speaker 3: there's all this dead tissue in your immune system like
45:31
Speaker 3: responds to it. Does this process have to get done
45:34
Speaker 3: in stages? Because if you've killed too many of your
45:36
Speaker 3: cells all at once, your brain now has all of
45:39
Speaker 3: this dead stuff that it needs to sort of process
45:41
Speaker 3: and deal with. Or do you not know because I
45:44
Speaker 3: were way outside of physics.
45:45
Speaker 1: Now I don't know in great detail, and maybe some
45:49
Speaker 1: cancer doctors can write in and let us all know.
45:52
Speaker 1: But I do know that the immune system will respond
45:54
Speaker 1: to this. And for example, if you get radiation treatment
45:57
Speaker 1: on a tumor, it can make the tumor swell even
46:00
Speaker 1: if it dies, Like the immune response there can make
46:03
Speaker 1: the tumor swell, which can also be dangerous because if
46:06
Speaker 1: it's next to something delicate, you don't want it to swell.
46:09
Speaker 1: And so again talk to your doctor about what the
46:11
Speaker 1: best treatment is for you and all those side effects.
46:14
Speaker 1: But we actually do have some data about what would
46:16
Speaker 1: happen if you shot a super duper high energy particle
46:19
Speaker 1: beam into your head, because it happened once. What Yeah,
46:24
Speaker 1: there was a Russian guy for Ghoski and he basically
46:27
Speaker 1: was looking down the particle beam. He was doing some
46:29
Speaker 1: repairs on the beam and they turned it on. Oops,
46:33
Speaker 1: and so it went right through his head. And amazingly
46:37
Speaker 1: the guy survived.
46:38
Speaker 2: Wow.
46:38
Speaker 1: He ended up with epilepsy and some hearing loss, and
46:41
Speaker 1: some people say his personality changed a little bit, but
46:44
Speaker 1: he lived his life otherwise. So I wouldn't recommend it,
46:48
Speaker 1: but it is possible to survive LEDC level energy proton
46:53
Speaker 1: beam through the brain.
46:54
Speaker 3: Oh my gosh, this happened at the LAC. No.
46:56
Speaker 1: This was definitely not at CERN or the large Hage
46:58
Speaker 1: of Competor. This is in nineteen seventy eight at the
47:02
Speaker 1: Institute for Hinenergy Physics and Provino back behind the Iron Curtain,
47:06
Speaker 1: and it was a nattally Burgoski.
47:08
Speaker 3: Poor guy. Well, I'm glad he made it.
47:10
Speaker 1: We're all glad that he survived, and we're starting that happened.
47:14
Speaker 1: I hope that it doesn't happen to you. But you know,
47:16
Speaker 1: the bigger picture is that particles interacting with matter is complicated.
47:21
Speaker 1: Particles from the sun and from the atmosphere can mutate
47:24
Speaker 1: your DNA and cause cancer, but particle beams can also
47:28
Speaker 1: deposit energy in those cancer cells in a very defined
47:31
Speaker 1: and very calibrated way to help treat your cancer. And
47:35
Speaker 1: so particles are on both sides of the coin of life.
47:38
Speaker 3: That's right. And I'm guessing that most of the folks
47:41
Speaker 3: who are working on these particle related questions did not
47:43
Speaker 3: have in mind that this would end up being a
47:45
Speaker 3: treatment for cancer. So you know, we're gonna go ahead
47:48
Speaker 3: and bang that drum that we've been banging so much lately.
47:51
Speaker 3: Fund basic research. This stuff results in amazing life saving technologies.
47:56
Speaker 1: Yeah, and you don't know if that's studying to like
47:59
Speaker 1: how ducks mate, or how to synthesize this random chemical
48:04
Speaker 1: or whether this parasitoid wasp, But does this or that
48:07
Speaker 1: is going to yield the next great bit of technology.
48:10
Speaker 1: That's going to save your life or a loved one,
48:12
Speaker 1: or transform our lives into some way we can never imagine.
48:16
Speaker 2: Amen.
48:17
Speaker 3: All right, everybody, thanks for listening, and we'll see you
48:20
Speaker 3: on the next show. Daniel and Kelly's Extraordinary Universe is
48:31
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48:34
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48:35
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