May 05, 2009 - 11:59 am
I was under the impression that once you received radiation on a certain part of your body, that area could never be radiated again. Apparently, with IMRT, that isn't true. Just as the IMRT allows the technicians to lessen the radiation as the machine moves over bones and uninvolved vital organs, should I need radiated again in the pelvic region in the future for any reason, they would use my records from this treatment protocol to design a modulated radiation pattern that takes into account previously radiated tissue. I am praying NOT to ever have a recurrance that calls for additional treatment, but it is good to know that IMRT allows for this tool to be still available.
I also asked about how having fluid in the bladder or not having had a bowel movement before a radiation treatment might affect 'what is where' inside me, since IMRT is so precise. I was told that adjustments for those tiny internal changes are made daily as they look at daily Xrays against the original 'simulation' positioning CT-scan. For my treatments I was told it didn't matter if my bladder was empty or full. Even so, every day before my radiation, I carefully mimic what I did the morning of my simulation CT-scan; drinking coffee and urinating before I leave for the hospital; and then drinking a 12-once glass of cranberry juice on the way for my treatment and not peeing again until after my radiation is over. The oncologist said this consistency wasn't important, but I read of a current Clinical Trial on IMRT pelvic radiation where they are testing whether the bowel or vagina move enough to matter if people have a full or empty bladder. (The Clinical Trial participants have 3 CT-scans a WEEK, and drink 3 glasses of fluid at a consistent time right before each treatment, with the Trial hoping to learn if it matters with IMRT if the bowel or vagina move a few millimeters.) Regardless, it seems to make sense to be as consistent with your simulation CT-scan as possible, right?
I was also told that I probably wouldn't begin to have an upset stomach or diahrea before the 3rd week of this.