Questions and Answers

Since I'm not with the guys experiencing radiation therapy first hand, I, like all of you, am filled with questions. Some I've been able to ask. I send others with Orion to ask. And The Google answers others - the National Cancer institute has a good page and I've taken a bunch of info from it - http://www.cancer.gov/cancertopics/factsheet/Therapy/radiation

Why radiation?
Way back in January when Orion got his diagnosis and the treatment protocol, I asked Dr. Hochberg - Ten or twenty years from now, will you say chemo was necessary but we didn't need radiation? He said an emphatic no. Reading I've done since shows a greater incidence of recurrence of the cancer when chemo is the only treatment.

What's being radiated if the cancer is gone?
Well, we no longer can see the cancer with an MRI, but an MRI doesn't show cellular data. Even one cell left behind can grow quickly to the size of the original cancer. So the radiation is directed to the exact shape of the original tumor, expanded somewhat beyond because since we can't see the individual cells, we don't know where the edges are exactly. And since the markers were in the spinal fluid, we need to make sure there's no cancer left in the spine either.

The spine is so long that it's done in 5 sections. How do the technicians make sure there's no overlap (doubling the radioactive dose) or gaps (no dose)?
The technicians make marks all over Orion so they can line up the rays. He says they move the dividing lines a little each day, so if there's overlap or gap, this shift will make up for it.

Why 30 little zaps instead of one big one?
There are two main reasons for once-daily treatment:
- To minimize the damage to normal tissue.
- To increase the likelihood that cancer cells are exposed to radiation at the points in the cell cycle when they are most vulnerable to DNA damage
Studies are now being done to see if even more fractionalization is better - twice or more a day. Some future patient will benefit from what's learned.

Does radiation kill just cancer cells?
No (sadly). The amount of radiation that normal tissue can safely receive is known for all parts of the body. Doctors use this information to help them decide where to aim radiation during treatment and how much to give. Orion is getting 1.8Gy per day per spinal section and half that per day for each of the 2 brain treatments.

Should we worry about cognitive damage?
Well I worry about this. But studies I've read show that with pediatric brain cancers, older is better. I guess when your brain is pretty well formed so it can handle being beaten up. One chart I looked at showed that by age 12, cognitive damage was minimal.

If you are wondering about any other aspects of radiation treatment, tell me and I'll see what I can find out.