[Music]
hello and welcome to technically speaking a podcast where scientists and engineers come together to chat about a common interest share knowledge and satisfy some curiosity i'm ellie and in this episode i'm joined by laura emma and priyanka to talk about radiation and how it's used in medicine as well as other areas of science laura you've worked with radiation tell us about it so i used to work in the nuclear industry and then ended up working at a radiation science or laboratory called
the dalton cumbrian facility which is run by the university of manchester i was working around a lot of radiation chemists i went to a conference with them and then ended up being a trustee of the miller trust for radiation chemistry so it's very nice to be acknowledged in that way i don't really think of myself as a radiation chemist though although i know lots of random things about radiation chemistry wonderful emma your experience is quite different why don't you tell us what
you've been up to well i'm a biochemistry student so i would say that my focus is less of physics and more of the stuff that happens in a body my interest is cancer treatment and basically radiation and its use in therapy is a big part of that amazing i'm looking forward to learning more about that later and priyanka you're also a biochemistry student but you've got a slightly different focus tell us about that yes of course so uh yes i am a biochemistry student so very similar
modules here i've done a dissertation in my second year on using nanoparticles in radiotherapy and how we can use nanoparticles with proton therapy to kind of deliver the most efficient form of radiotherapy possible amazing right so i am already confused because i know nothing about radiation and to me radiation is scary so i think we maybe we need some definitions to start off so laura do you want to clarify what we're talking about please i shall try yeah most people that have been through the
uk education system probably at some point were told something about alpha beta and gamma radiation it's basically different forms of things that cause an ionization so effectively causing electrons to be knocked off an atom and this can do things like break chemical bonds or lead to the production of different types of chemicals depending on what's happening with it and those different types of radiation act in very slightly different ways so an alpha particle is obviously something
that's a little bit heavy it's got some mass it doesn't penetrate very far beta radiation is essentially electrons they can do slightly different things to alpha particles and gamma and x-rays basically like light but with higher energy so they can be quite penetrating they all lead to these ionization events i see so what's the difference between someone having radiation treatment in medicine and the radiation produced by you know like um chernobyl or like nuclear radiation or atomic weapon
radiation oh as far as a physicist is concerned they'd probably say not a damn thing [Laughter] but in medicine it's more controlled it's more confined um it's administered very carefully the dose is carefully thought out the area of the body that it's applied to is thought out as well and i guess one of the main differences certainly with an atomic weapon is you get something called fallout so you get radioactive particles in the air that then can seep into the ground and be absorbed by
biological structures like trees and people and obviously you don't get that in medicine again because it's quite controlled and it's not something that's released into the environment in the nuclear industry it's also really well controlled as well and in the radiation labs that i've worked in again it's incredibly well controlled so although it's the same physical phenomenon it's managed differently to make it safer than just letting radiation go out there in the wild and
do its thing probably also worth pointing out that there are lots of radioactive isotopes in the world naturally anyway and in your own body and in the food you eat the difference is the concentration that it's there in so when it's more concentrated there's more radiation that can do more ionizations so i've learned that we are now all slightly radioactive incredible yeah and when someone says something is radioactive what they mean is it's above a certain level where it can be detected
above what's naturally out there wow okay i'm interested so i'm even more interested in how this radiation therapy works so emma and priyanka why don't you explain the medical terms and how it works within the human body so basically radiation therapy the way it works is that we have a dose of laser or like radiation that we kind of administer onto the patients before doing that we kind of map out the structure of the tumor or like the area at which we want to target this radiation according to
that we decide on the dose on the strength of the of the radiation as well as the kind of radiation we use because as we know that there are multiple kinds that we can use based on their potency based on um how strong we want them to be and based on the depth of the tumor itself after we administer that dose we have to take into account that there are cells that are affected by the radiation upon entry and the exit kind of surrounding the tumor itself so what we aim to do is
balance out how many cells are damaged in the process what we're trying to do is ensure that the least number of cells are damaged on the entry and exit pathways because of which we have all these different sorts of right like radiation available amazing so if i or someone who had cancer one of the like treatments available would be using this like really targeted sort of laser approach of radiation to kill the cancer to kill those cancer cells effectively and you're trying to minimize the other
cells that get damaged within that process exactly so the way radiation kind of works is that it targets actively dividing cells so cells that are kind of resting they don't really get affected as much which is why it's such an attractive target for cancer cells because as we know tumor cells they just continuously divide there is no stopping them that's why it's kind of like a magnet attracting all the radiation to it but as we know that some form of radiation isn't as precise as we would
like which is why we have so many side effects which is why some of the side effects can even show up like weeks or something after a doze or like a radiotherapy uh routine that we have sorry a course so if i had radiotherapy there's a chance that i could end up with some extra abilities i'm thinking spider-man gets bitten by a radioactive spider so not only will i hopefully be cured from the cancer i'll also you know get some extra benefit i wish that's how it works
because then we'd have like a whole bunch of superhumans here but i don't think that's how it is at this point it's not gotten to that level yet but i'm sure that there is someone out there some professor doofenshmirtz who's like trying to create that in their labs i have heard of studies where they use radiation to create some sort of like seeds for rice that are resistant to drought for example but i've never quite understood how they they must modify the
genetics in some way using the radiation i've never understood how and seed is obviously a lot less complicated than the human body so be interesting to understand if you could have that same effect on a much larger organism i doubt it i think humans are too complicated and the human body's got some really good repair mechanisms for that sort of thing yeah i maybe would um say how radiation works in the actual cell when when the radiation hits a group of cells radiation ionizes water which
creates radicals which are molecules which are highly reactive and these create double-stranded nicks in our dna every single cell has a repair machinery inside to make sure that these breaks are repaired but since these radicals are so reactive sometimes the cell doesn't know how to repair the the cut so what we get is basically a large portion of the dna is then deleted and if like a detrimental part of dna is deleted the cell is unable to function and basically dies
if we were to compare radiation therapy to for example chemotherapy i wouldn't say either is better than the other because the main aim of the doctor is really to assess the cancer for example if we have a cancer like melanoma which is skin cancer and it's spread all over the body we can't just radiate the entire body because that would kill the person because the radiation will be all over their body damaging not only cancer cells but also healthy cells so doctors needs to focus whether the
cancer is local such as like a tumor and the lymph nodes for example or systematic i would say all over the or malignant so you're saying that the radiation works best in this form if it's sort of in one very specific area so you can focus it all to target that specific tumor yeah i would say it it works the best because it minimizes the damage to to healthy cells chemotherapy as well as well as radiotherapy it affects um rapidly dividing cells which are also healthy cells such as our hair
and that's why we sometimes see cancer patients losing their hair because it's affecting everything not only on not only cancer cells oh this is super super interesting and some cells may actually be resistant to radiation if if the cancer is locally located very deep in the body such as renal cells in the kidney if the doctors choose a high dose it may not have the same effect because it's so deep and it's just does more damage than good basically in that instance where you're talking about
using a high dose x-rays i think is quite a common radiation therapy but x-rays kind of lose energy as they proceed through a body or matter or whatever it is they'd be ionizing the healthy material or the healthy cells before they get to the tumor and then they'll be less effective when they get to the tumor because they have less energy yeah and i would say the big problem with radiation therapy currently is it's very hard to um let doctors learn all this stuff about
radiation therapy because they need to estimate the proper dose that needs to be delivered they need to locate the tumor which at this point is very invasive because sometimes they need to do it surgically or like the person has to do a ct scan to locate the tumor and it's quite invasive but the current um focus and in radiotherapy is using ai to help doctors with the accuracy of the treatment basically what they're trying to do is using deep learning of ai try to compile
as much data as possible and help estimate the appropriate dose for the patient but also estimate what type of outcome the treatment would have if it's even required or if it will even be effective so they're using artificial intelligence to work out how much radiation to give someone this is insane yeah i don't understand artificial intelligence is the best of times but i love that there's this application of it that can help people that are suffering from these like
diseases it's wonderful yeah i think it's amazing as well because it's it's so quick and i feel like it can improve the the outcome of so many patients with just a few minutes whereas now the surgeon has to be highly trained with i don't know how many years of practice to sort of figure out where how to how to treat the the disease and maybe in a few years it'll just take like a 10 minute exam to estimate what type of treatment the patient will need so how far away are we from like ai
based treatment is this something you could get tomorrow or five years 10 years what do you reckon we're looking at the latest paper i read on using ai in radiotherapy was only in 2020 it was described described as sort of an emerging therapy target but i would say maybe 10 years i mean definitely within all of our lifetimes then really yeah oh 100 percent 100 so is the idea that the artificial intelligence takes all of the information that's been published in
medical journals about different cancer therapies different types of cancer different patient outcomes different different ways of treating the cancer which i guess we should talk about in a bit more detail and figures out how to match all those things together to give the best treatment for that particular type of cancer in that particular person yeah exactly wow this is so clever you could think like all the data that we could feed it it could learn so much more
and like you could apply it to this but then in theory you could apply it to lots of other diseases as well yeah oh yeah a huge data set to feed it and see what i can make it with my very limited knowledge of ai feed the ai it's what we need to do we just had one at work where they uh fed an ai and like deep learning and it they taught a robot to peel a banana they just like did it over and over and over again and then the the robot learned the like level of touch required
to peel the banana which i just think is so cool but then you think oh they've taught to peel a banana with the soft touch but they wanted to teach it to do like medical procedures to like sew people up and incredible and that banana is the first step interesting link between bananas and radiation is the banana equivalent dose because bananas contain potassium and there's a radioactive isotope of potassium so all bananas have some potassium in it's quite a common way of
um making radiation more understandable so radiation doses are usually talked about in sieverts you can equate that into like the average dose from a banana so how many bananas for that equivalent dose so there's another benefit to eating bananas as well as your five a day it's also like your radiation dosage um i wouldn't quite put it like that it'd still be a little background but that sort of information like how much radiation are you um in contact with on a daily basis is
taken into account when you're working out what happens in the human body when you're exposed to more radiation um it goes back to when we were talking about as well repair mechanisms so the human body is exposed to radiation in emma mentioned radicals all the time radicals are produced in the human body during normal metabolic processes from what i've been told from chemists and the body's got some very good ways of dealing with that so the natural radiation from your banana body knows
what to do with it i find this very mind-blowing i think popular science has like really altered my perception of radiation to be like all radiation is bad you know you're gonna end up in hospital because like you know they got the chernobyl documentaries and all that that sort of thing but actually like if bananas are mildly radioactive and containing these radicals and these isotopes and i eat bananas every week and i'm fine touch wood then like this is it's crazy to me
that it can be both bad and good like simultaneously yeah like you can use use it to cause like cell death of a tumor and also keep the person like essentially healthier than they were before and also it's just it's just in the air it's like the um invasive species from last week like they're all around you and you might not know and this radiation is all around us and you like i didn't necessarily know so i find this really really interesting are there any more like applications of
like radiation and ionizing radiation in there in well not necessarily day to day but you guys know what i can think of a few but it just occurred to me that priyanka mentioned nanoparticles and we haven't really explained how they work in radiation therapy that's a big one that's a big big one so it's really really it's kind of very new research right now but when we talk about radiation therapy we talk about finding the right balance about like the right dosage and the
right strengths and everything right the way nanoparticles work is that they sensitize specific cells they kind of make tumor cells or whatever cells we kind of put them in a lot more sensitive to the radiation which just means that if a specific group of cells are more sensitive we can use a lower dosage of the radiation themselves so that kind of avoids any a lot of the damage that can occur in the healthy cells because it's not strong enough to actually cause significant damage or
like dna damage and everything in healthy cells it's just enough to to target the tumor cells and kind of cause them to go through all these changes and kind of apoptosis and everything moreover we can actually add the chemotherapeutic drugs that we use onto the nanoparticles we can kind of coat them on the surface which is basically like chemotherapy plus you know increasing the sensitivity of the cell and the cherry on top is the radiation it's like a trifecta of like
killing the evil villain in our body and just kind of targeting the cancer cells directly i mean wow that's all i can say so it's like it's like a triple threat you've translated all of cancer treatment a proper knockout at this point like the tumor cells have no chance against it you know yeah and the best part is my research kind of focused a lot on using proton therapy and nanoparticles the way proton therapy is a bit more accurate than regular radiotherapy is that it uses protons
which deposit their energy at the end of their at the end of their path during the entry dose they don't deposit any energy or it's very insignificant so none of the healthy cells kind of get any of that ionizing radiation that laura was talking about only at the end when they reach uh that limits do they deposit most of their energy about let's say about i'm not really sure about the exact percentage but i would assume about 70 is 80 and on the exit dose there is nothing
it's like zero percent there's nothing at all so the damage that we were concerned about on the entry and exit paths are reduced to the point of just being negligent that combined with nanoparticles chemotherapy all of that stuff just kind of together it's it kind of feels a bit like utopia like it just seems too perfect to be true which is why there are a lot of clinical trials and everything happening right now because nan particles have been used in radio in
conventional radiotherapy but not in proton therapy there's a whole world out there of like possibilities opportunities and everything so it's a very very exciting field right now conventional stuff that would be with gamma rays that are delivered from a source that's external to your body is that right yes i believe gamma rays i think the most common form of radiation is photons they kind of deposit their energy throughout the pathway so that's why it's not as effective in tumor cells
you can really focus proton beams back to particle accelerators again that's where the protons are made there are x-ray generators as well um or a different type of source you can have just a naturally or occurring isotope that will give off gamma rays or x-rays you can also get radiation delivered internally as well can't you so you have like little beads that sort of encapsulates a radioactive isotope and they can be delivered to a site which sounds similar to the
nanoparticles stuff but it's not sensitizing the cell to radiation it contains the radiation in it yeah a radiation can be used also in internally and i would say that we we could use nanoparticles as small delivery roots to deliver radiation successfully with all of these how are you getting it in the first place say i again am the hypothetical example that i'm unwell and i need this radiation therapy even these ais these new ones like where is it coming from is
it like in a homer simpson style box within he's taking it out with like gloves or like is it in a special machine like where how does it how does it exist in the hospital in a way that is like safe for them it to be delivered to me um i would say the one way we could um we could design the nanoparticle is to alter the the characteristics of the actual molecule the the drug is bound to so for example if if the tumor is in the brain we can make the molecule really hydrophobic
so it gets delivered there rather than the bloodstream which has a lot of water oh brains don't have water that's what i got with that well for a drug to go into the brain it has to cross on the blood brain barrier right and it has to be hydrophobic okay and this is very hard if for example the drugs are delivered via my blood so intravenously for example right so brains do have water in them sorry [Laughter] and just just um increase their bio availability or basically just influence how much
drug is delivered to the site that we we want because most drugs are broken down and as they enter if we engineered the delivery molecules in such a way that they would resist this breakdown that's how we ensure that it it goes where it needs when it needs to be basically i just love that we can engineer this on like a teeny tiny level i had no idea that this was even possible and even when priyanka was saying about the the three-step process that you can make the cancer more
susceptible before you even do anything with the radiation this is i mean this is a whole world that i had no idea about so this is absolutely fascinating um yeah you're talking about these teeny tiny molecules but you also asked um how is it delivered and particle accelerators that i worked with that would deliver the proton beams were kind of large like wouldn't really fit in my house easily say so you've got these tiny tiny particles and this massive machine and they both
have to come together to do something to your body that is beneficial and x-rays can be generated in a similar way from a machine whereas if you have a nanoparticle that's radioactive i guess that is an isotope that is generated probably in a research reactor maybe um but generated in a really controlled way and then carefully stored and handled and shipped because yeah when you say particle accelerators all i think of is cern and it being like five or six kilometers long or whatever
it is oh no not quite that big um but cern cern serves a different purpose they're looking for strange particles not delivering things we know a lot about in a very controlled way this shows my absolute zero knowledge of this topic because like particle accelerators radiation all of these things have so many more uses than i even could fathom existed which i think is is awesome laura did you want to tell us more about different opportunities to use these processes
yes so we've talked about x-rays and obviously they're used to take pictures of the human body to see what's inside it so that's one different application of x-rays but they can also be used to look at materials as well so if you think back to high school physics do you remember doing the double slit diffraction experiment with light where you shine some light through slits and you get a diffraction pattern appearing on a wall on the other side i did it through a prism but that is going back
a long whole time very enough or you can do something similar with x-rays because they're a different wavelength they diffract through the space between atoms so then you get a diffraction pattern that tells you something about that material or that substance and it's actually how the structure of dna was found so by diffracting x-rays through crystalline dna i mean i live in cambridge so this i actually do know about [Laughter] the space between atoms is useful i love
this teeny tiny stuff like normally i do big things or whole organisms at the very least even whole ecosystems but to me to look at it stuff on a molecular level a nanoparticle level is so fascinating do we know any like further things that we could do with it because i feel like this is a whole world i haven't explored like i've heard that you can radiate animals like mosquitoes to make them sterile like i have no idea how that works but i think it's a good idea
i think it's an interesting idea does anyone else know any more about it i tried reading one paper about this that said they basically gave them radiation doses to different amounts and then put them in with some females to look at how they reproduce or whether they reproduced at all they just kind of figured out what dose to give the mosquitoes to sterilize them based on that but exactly how it works how it sterilizes them without doing more to them i'm not sure it did also apparently
make them less competitive with non-radiation sterilized mosquitoes so there would be mosquitoes that were more desirable to the females but i didn't get much out of it beyond that they just kind of found those two observations and didn't go down to what happens to their dna which i was a bit disappointed by because i really like looking or hearing about atoms as well the the reason they're doing this is so that there are fewer mosquitoes in the world to spread diseases like
malaria some they don't need to be so interested in what happens to the atoms they just need to see the end result yeah i guess that makes sense it's just crazy to me that like we're talking about radiating a tumor in a human body which to me is at least you know maybe golf ball sized or smaller but still sizeable but then you can radiate a mosquito which is tiny in the first place even tinier if that makes sense to then make it sterile like these doses are ridiculously small or
they must be i mean i'm not entirely sure which is just super impressive i mean they're not like firing proton beams from a particle accelerator individual mosquitoes this is what i'm imagining that would be interesting though i think they put them in a box and put them inside an irradiator that uses gamma rays for example because gamma rays will pretty much fill that chamber and go all the way through the mosquito and then be absorbed by the surroundings of that chamber
so the gamma rays don't escape that's what i think they do so yeah they just literally apply different doses of gamma radiation to the mosquitoes to look at the effects that's also how food can be preserved so similar to the mosquitoes they can apply this measured dose of radiation and it will kill the bacteria on the outside but won't destroy the sugars or whatever else is inside the food like a strawberry for example so the strawberry stays fresh and tasty and is perfectly
safe to eat gamma rays don't make things radioactive they just break molecular bonds hang on hang on hang on we're firing radiation at strawberries which is killing bacteria but not damaging the strawberries so that i can still eat it yep and i guess again that assuming the strawberry isn't alive once it's been picked so it still cells stop dividing but the bacteria on the surface are dividing going off what emma and priyanka were just saying that bacteria will eventually die because it's going
through the process of cell division i'm i'm guessing here you guys can correct me if i'm wrong i literally yeah yeah just as laura said that uh bacteria are dividing and if we fire radiation on them dna breaks and then they're unable to survive so killing them ethically as well as maybe if you can apply ethics to particular bacteria bacterial rights isn't it the question of are we valuing the life of a bacteria more than a human who could have potentially been like
infected of some sort of a disease are you saying you want the bacteria to survive so they can go and colonize people's colons or like you know infect people with like salmonella even though salmonella doesn't really happen from strawberries but it's a it's food for thought it certainly is i'm not saying that this radiation won't affect the taste of the strawberry so it's killed the bacteria but it's not affected in any way the flavor of the straw that is what i have
read i've not to my knowledge i've not eaten a strawberry that has been irradiated but i may have and i just don't know when i wouldn't know the difference but it's better way of preserving food in that instance than pasteurizing something for example or heating something to kill the bacteria because that would affect the strawberry a similar way that it works is for example in the doctor's office when they put their surgical equipment under uv rays uv also damages dna i would say in
sort of a similar manner that it kills the bacteria on top and leaves the leaves just the equipment sterile and they're like those autoclave machines right like is that what they're called the things they use in the barbers as well like to sterilize their tools so it's just like a high-dose radiation hit like within a box essentially and then that kills the bacteria and then it's sterile for the next person that needs surgery or a haircut or is this craving a strawberry
i know i'm just gonna have to go to the shop after this but then so is this common practice is irradiating food like in the mainstream if i go to co-op can i buy this sort of thing i'm not too sure what happens in the uk or where it happens but you can definitely read examples of it i've seen an awful lot of research papers from irradiation of condiments like ketchup and mustard i mean i do love mayonnaise so maybe i can get on board with it yeah i don't think they came
from uk researchers but you know if you've got some condiments and you've got a radiation source and some time on your hands and you want to write a paper and get it peer-reviewed why not what else can we do with the radiation because i think also being the pop culture influenced person that i am like isn't the hulk powered by radiation or his exposure to it like causes him to become hulk-like so can we create can we create super monsters and baddies not i'm suggesting
we should the hulk is an avenger after all like is this when you get these like crazy side effects like obviously the hulk is not real but you hear these things like the fish living in chernobyl waters and things like that like grow to eyes like that's the stereotype yeah well i personally hate saying that something is impossible in biochemistry and i was actually thinking about like under what circum circumstances could we create like a radioactive monster like godzilla or something
and i would say if we wanted to do it if we were like an evil scientist we would have to probably make like a few beetroot dishes with lizard embryos irradiate them with radiation and we would have to hope well it's highly improbable and we will have to hope that the repair mechanisms would insert a certain bit of dna maybe we could engineer them to do it that would make the lizard grow i don't know to be as big as empire state building fire and hope that the nbo grows into a full
lizard and maybe that's why it's very improbable but but not impossible for now for now it's the repair mechanism that's responsible for doing that it's not necessarily the radiation it's what the body then does next to respond to it so this this potentially this idea could be unlocked like we could all have the potential to be superhuman if we got exposed to the right level and then repaired and then mutated and then also survived potentially isn't that the basis of the
x-men though that it was like the next evolution in humans that you'd develop all these wild different features kind of going back to our biomimicry episode i was just thinking my quest my quest for built-in box openers inside my hand is one step closer this is amazing do you need to find the right radiation dose that affects the right bit of dna that is affected by some sort of biological repair mechanism in the right way done you can have your tail and your little box got the claw
emma and frankie you've got 10 years to sort this out for me i'm just not working on it right now thanks very much well that sounds like a good place to leave it we've deviated pretty far from the original topic so i think this time we draw the conversation to close we've covered ionizing radiation cancer therapy nanoparticles and pretty much everything in between so if you'd like to carry on this conversation you can find us on twitter and instagram thank you very much for listening
the views expressed in this podcast belong entirely to the person that said them they do not represent any industry or organization if you enjoyed listening to these views it would really help us out if you could rate us leave a review and tell a friend this podcast was sponsored by no one but if you're interested in funding us to continue to have frank discussions about science and engineering please get in touch [Music]