Saturday, September 22, 2012

Battle of the hippocampus, part II

What oncologists do best is diagnose and treat cancer. While I generally trust their specialized skill set, they are not omniscient about the brain. Especially when higher brain functions are being put at risk, it wouldn't hurt to have a good memorologist available when you need one.

The plan to start radiation therapy this past week was postponed when I learned that my oncologist intends to spare my left hippocampus from radiation exposure but not my right. I only discovered this when I quizzed the therapist on Wednesday during a rehearsal of my treatment protocol. She told me that Dr. S had concluded that the structure was too close to the tumor bed (perimeter of where my brain tumor was) to risk not irradiating the whole right side.
Chalk this up to poor communications. It was my understanding that both hippocampi (that's plural) would be spared, so this bit of news came as an unwelcome surprise. I called off my appointments until I could get a second opinion on the matter.

The hippocampi is that bit of brain space where memories are made, so to speak (see previous post). No one undergoing whole-brain radiation should ignore the potential damage this procedure can do to short-term memory and concentration. Oncologists, in my opinion, take too lightly the preservation of the hippocampi, erring instead on doing everything they can to stop cancer from recurring. While I appreciate their instincts, you need to count the costs before proceeding when brain function is involved.
I now concede that my radiation oncologist was correct in her original plan. It was explained to me yesterday by my neurosurgeon that while the right hippocampus is a safe distance from the tumor bed itself, the cavity created where clotted blood was evacuated from behind the tumor extends much closer to it. This is where microscopic cancer undoubtedly remains after surgery and that needs a good zapping to be cleaned up. It's therefore unavoidable, I've reluctantly concluded, that the right hippocampus be exposed to the same radiation dose as the rest of the brain.

Given my sensitivity to this subject, I wish my oncologist had told me in advance what she had planned and why. My distress and the cancellation of appointments could have been totally avoided. She should not have assumed that I wouldn't have an interest in how and exactly where my brain was being irradiated. It is, after all, my brain.

Fortunately, of the two hippocampi, the left side is dominant and can take over some of the function of the right. Again, I had to learn this from my neurosurgeon, who seven weeks ago resected my brain tumor. He did his work masterfully. I’m hoping that I'll do as well by the radiation oncology group here in Corvallis. They’ll get their chance starting Monday when they take aim at my brain with one of their big guns.


Carl Pelz said...

Thankfully, you are an inquisitive and effective learner as well as one who takes proactive ownership of his health (in this case, your brain). You're also modeling good behaviors for the rest of us! It would be good know your upcoming schedule of RT treatments.

Peter Ogle said...

If everything goes to plan, I'll have 20 treatments--every weekday for the next four weeks.