I’m working on page 44 of my cancer comic, and I’m trying to explain how radiation therapy works, in very generalized terms. Obviously I’m simplifying and stylizing some of the cellular level stuff, but can the more scientific of y’all check the overall factual nature of the page?
I’m going to ask the techs tomorrow, but appreciate your knowledge
Thanks in advance.
It looks good! IDK if you want to get into this kind of detail, but X-rays kill cancer cells in 2 ways. One is the immediate death that you described (note: some healthy cells that cannot be repaired die too (called "apoptosis") but are quickly replaced by new healthy cells). The other is a delayed death of cancer cells. Their DNA is damaged and the cell goes into a dormant state. When it eventually tries to replicate, it can't and dies. This is called "mitotic catastrophe" and can be delayed for years.
Great detail! Thanks! Yeah, I kinda understood about healthy cells, but I guess I assumed they were replaced as part of natural processes.
I call the damaged cancer cells "zombies" - they are dead but they don't know it yet. It is a source of frustration to radiation patients because until they truly die and vanish, they leak PSA into the serum. It took me 3 ½ years to reach PSA nadir. Radiation can be frustrating for those who want to see quick results.
Not enough room to say, but I think the radiation is focussed on the cancerous lesion as closely as possible, to minimize hitting surrounding healthy cells. And that some cancer cells can repair their DNA. My prostate received 30 IMRT in 2021, but a PSMA-PET scan in 2023 showed some cancer remaining in the gland, and a second scan 8 months later showed it had grown larger than the original lesion.
Love your comic, JP. Your fascination with the linear accelerator matches mine (but I'm an engineer, so what do you expect?). On my last visit with my RO, I asked to see the thing so I could prepare myself for the 28 rendezvous that lay ahead. I've also studied the complicated components and their interplay that form the electron beam. Beam focusing is tricky, to say the least, especially on organs that like to move around during the treatment. Best wishes for your continued treatment. BTW, my RO told me that cancer cells are more sensitive to radiation than healthy ones and that's why it works. It's sort of like a 'last man standing' scenario. She didn't invite any more questions on the subject. 
just a nit - wrt the statement “…generates X-rays … in the form of photons” ..
Feel free to ignore me; but this is a bit redundant - all X-rays are photons, this is the only particle that manifests as x-rays.
But not all photons are x-rays; what distinguishes X-rays from various other photons is the energy level: X-rays are very high-energy photons. The high levels of energy create “ionizing radiation”, i.e. it ionizes otherwise neutral atoms (i.e. it kicks electrons out of their orbits, leaving behind charged atoms = ions).
I haven’t dug much deeper with ionizing radiation, but it’s my guess that the ionization at a molecular level releases heat energy and free electrons, both of which contribute to what ultimately causes the DNA damage at the cellular level … I’m thinking that charged ions disrupt the normal biological activities at cellular level, leading to breaks in the DNA chain. When the cell eventually tries to reproduce, it fails since the damaged DNA doesn’t replicate properly.
Total disclaimer on that last paragraph - it’s mostly speculation on my part.
I was making the point that they’re photons, as opposed to protons. The techs during my session seemed to like that I made that point. People choosing treatments have lots of terms thrown at them, and I wanted to introduce the idea of photon therapy vs proton therapy, so they’d know which I was talking about.
In color, maybe?
Good Luck, Good Health and Good Humor.
j-o-h-n
I wonder if you could try to add in the reason for why the machine rotates around you. It focuses the beam at your tumor from a large number of angles so that all of the beams intersect in the tumor and give it the most radiation, while giving less radiation to the surrounding tissue because it only gets it from one (or possibly two) angles.
Dang - I'm impressed with you artsy folks. I struggle with a round head on top of a stick figure.
On another note, I found a T-shirt with PEW PEW PEW on it (Star Wars at it's finest). I wore it to the some of my EBRT appointments laying in the plank with the Big Ass Machine Techs cracked (I should have found a Flintstone t-shirt with BAM BAM on it and let those young Radiation techs take their best guess what it stood for)
I did NOT wear the t-shirt when I saw the R.O. ; she didn't convey a personality with a sense of humor 
Keep up the art work !!
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