Friday, October 21, 2011

Microwave Cooking

Everyone did their best to make the experience as pleasant as possible.  The receptionists always seemed happy to see me.  The nurses and technicians were friendly and helpful. The specialists were knowledgeable and skilled.  I still go back every other week to see their social worker and therapist, as she helps me sort through the recent changes in my life, and the old wounds it has brought to light.  The radiation oncologist had an honest and casual way about him that really clicked with me.  Even the waiting room was beautiful, with a huge fish tank containing a variety of exotic salt-water fish, including several predators (I'm guessing everyone was too big to be appetizing, though the eel did take a chunk out of the lionfish's tail).  None of that changed what I had to endure.

First they did a CT scan, which they aligned with MRI images from before and after my surgery, to get an accurate current picture of my brain and the disease within.  They molded a sheet of perforated plastic over my head and shoulders, so tight it pressed against my eyelids, and held my lips nearly still.  This mask would become my companion for the next six weeks and I would grow to hate it, even though it did me good.  The idea was to hold my head perfectly still; they would be firing photons at my brain and none of us wanted them to miss.  They stuck me with a pen-like needle, slightly off-center on my chest, on my forehead behind my hair line, and on either temple.  The tiny blue dots left behind are in every way and by every definition, tattoos.  I still have them now, and will have them for the rest of my life. 

The room to which they lead me was marked with radiation warning signs.  A pair of lights, one red and one green, sat above a thick vault door.  A bank of computers lined up along a window to view inside.  Within the room was a huge machine, a narrow black plank before it, a cradle nearest to the machine.  I laid upon that bed, and set my head upon the cradle.  The bed rose, and shifted back, closer to the machine, as they shut out the lights.  Red lines of laserlight emerging from the ceiling and walls streaked my face.  These they aligned with my new tattoos.  Then came the mask.  They would settle it over my face, often asking me to tilt my chin up, or down, or move up slightly.  Then they would clamp it down tight, so tight I could feel my pulse in my face, and that it would leave a grid-like mark behind that would take a few minutes to fade.  They placed a cushion under my knees, and handed me a foam ring on which I could hook my hands and relax my arms.   

To say it was like getting an X-ray would be an understatement.  The machine and bed would rotate, and instead of the one or two quick shots of an X-ray, I received five, 10-second blasts, accompanied by a loud buzzing sound.  They called each blast a "field."  I kept my eyes closed most of the time - it was hard to open them - and during each field I saw a blur of bright violet light, as if someone was shining something in my eyes.  I would also smell an intense, unpleasant odor, like a cross between chlorine and metal.

I immediately knew there wasn't really a smell.  It took me about seven treatments before I realized the light wasn't real either.  They told me it wasn't that uncommon, for patients to hallucinate during treatment.  My olfactory and optical nerves were being directly stimulated by the radiation.  In time, the smell would fade and I didn't much mind the light.  Oddly enough, I found I could prevent the smell by holding my breath.  Since there was nothing to actually smell in the first place, I can only conclude that my mind's assumptions overrode the stimulation: I cannot smell while holding my breath, therefore I was not smelling anything no matter what my nerves signaled.  Holding my breath was far from an ideal solution, as the mask was so tight on my nose I had trouble breathing, and after they took it off it my nose was so tender I felt as though I'd been slugged.  Eventually they cut the nose out for me.  The masks's nose.  Not mine.

The treatments lasted about fifteen minutes each, from mask on to mask off.  The technician told me if I ever needed to stop I could just raise my hand and she'd be there in two minutes.  That's how long it took to get the door open. 

The radiation machine is surprisingly sensitive.  Looking up at it, it looked like a pane of glass with striations of metal within, which could open and close and usually formed a sort of crescent shape.  These arms would vibrate during a field, and I was told that if they couldn't vibrate quickly enough, or if there was any sort of power variance, the field would end immediately.  Another safety precaution.

I find it fascinating how radiation treatment actually works.  I'm going to go a bit sciency here and this is all off the top of my head and from my best understanding, so forgive me if I mess up any details.

Healthy, normal cells are actually highly resistant to radiation.  It takes quite a lot to cause any real damage.  The problem is cell reproduction.  During mitosis, the DNA lacks its usual protection and is susceptible to radiation damage.  Now, because cancer cells reproduce much more often than healthy cells, they are in this vulnerable state more often.  They are also often less "stable" than healthy cells.  While radiation can (and does) damage healthy tissue, it damages diseased tissue much more easily and often.

From what I understand, the radiation itself attacks the DNA strand both directly and indirectly.  The photon's wavelength matches the width of DNA, making it easier to strike directly.  They also interact with the water molecules surrounding the DNA to create a burst of free radicals, which can also damage the DNA.  That means that during radiation treatment, drinking things that are high in anti-oxidants can actually be detrimental. 

So the idea is to damage the DNA so that the cell can no longer divide.  Sometimes this takes a few generations as DNA damage adds up.  They irradiate everything within 2cm of known cancer tissue, in an attempt to kill any remaining cancer cells that were inoperable or invisible, as they tend to roam away from the primary tumor.  My total dose was 5,400 sieverts (I believe that's the unit of measure they use), over 30 treatments.  My doctor said that they usually give between 4,500 Sv and 5,400 Sv, finding that any less than that was ineffectual and any more than that caused too much damage to healthy tissue.  The internet says a typical treatment is 45-54 Gy (gray).  I don't know if one grays equals 100 sieverts, or if I just searched for radiation therapy terms and thought that "sievert" sounded like the word he said.  My doctor told me most people just call them "rads," but that that's not really accurate.

The big question is, if this can damage cancerous DNA then can't it also damage healthy DNA?  It can.  It can even create new cancers (called secondaries), or accelerate existing ones.  Even when it doesn't, there are other side effects I'll describe next time.  It's all about risk versus reward. 

Until my MRI on the 26th, I won't have much of an idea which won out in my case.

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