RADIATION TREATMENT -- long version, December 19, 2010
The radiation mask-making on Friday, December 17, 2010, was not nearly as high tech as
I had imagined. They first did a special CT scan with external reference points and
markers to localize the remaining tissue and create a computer model. In order to have
my head (and thus remaining tumor tissue) in the same place each day, they make a mask
that into which I fit. The mask begins like the flat piece of plastic on the left of the photo. It
is warmed and then molded on the face, my final product being what you see on the right.
After that, they do another scan to match up the mask and model. Thus, my brain will fit
the computer model every time I put on the mask. This allows precise and repeatable
localization. That’s it. Too simple. The first day will be a “dry run” without radiation to be
sure all is well.
In the meantime, the high technology is in the radiation plan and treatment. Called
stereotactic radiosurgery or stereotactic radiotherapy, the process is a highly precise form
of radiation therapy used to treat, inter alia, brain tumors (or, as in my case, the pieces of
the tumor not removed) by delivering precisely-targeted radiation at much higher doses
than traditional radiation therapy while sparing healthy tissue organs nearby. (That is
good thing when dealing with the brain!) The process apparently relies on several
• Radiation damages rapidly dividing cells (like tumors). To minimize damage to
normal tissue, the radiation is divided into 30 small doses.
• Radiation travels in a straight line and irradiates everything in its path. To
minimize collateral damage to skin, normal brain, and other tissue, the orientation of
the beam is changed so that the central area (tumor bed) is always in the beam, but
the other areas are periodically spared.
• The radiation oncologist MD works with the physicist and designs the
treatment program considering all of these variables.
• The mask is to immobilize and carefully position the head—the low tech part.
• Gamma radiation fries the tumor.
• All the while, they have to miss the plates in my head and avoid radiating
anything that is overly sensitive.
There is, of course, an entire team here working together. It is headed by the
neurosurgeon who did the surgery: Steve Tatter, MD. Also on the team is the medical
(chemo) oncologist, Glenn Lesser, MD, and the radiation oncologist, Michael Chan, MD.
Some of the members of Chan’s radiation team include:
• The radiation oncologist (Chan) and his head resident who oversee the
radiation treatment team and oversee the treatment. They outline the targets to be
treated, decide on the appropriate radiation dose, approve the treatment plan, and
interpret the results of the radiosurgical procedures.
• The medical radiation physicist uses special software to devise a treatment
plan and calculates the exposures and beam configuration to treat the targets to the
• The neuroradiologist who interprets the brain imaging that identifies the
targets to be treated as well as the response to treatment.
My appointment with Dr. Tatter, the neurosurgeon, is on Monday, December 20, 2010, for
a surgical follow-up. I will get my stitches removed at that visit. Sometime that week, I
should get a call from Dr. Lesser, the medical oncologist, after he receives the results from
the MGMT analysis (an enzyme in the tumor). Whether or not the tumor has this enzyme is
what guides clinical trial enrollment. I can enroll in the clinical trial either way, but the
treatment I would get (2x per week vs. 5x per week) is dictated by my tumor’s MGMT
status. The clinical trial is of a drug called of cilengetide, which would be a second
chemotherapeutic in addition to the standard temozolomide (brand name Temodar).
Once the results from the MGMT analysis are complete, The Team (all of the above MDs)
will meet, and the schedule for the radiation, chemo and clinical trial enrollment will be
made. Likely all will begin the first week of January, in order to allow sufficient time for the
surgical incision to heal before radiation. The radiation will last six full weeks, and the
chemo will be concurrent. After the radiation is complete, Lorrie and I will return to New
Jersey, but what I will be able to do and where I will be able to go will depend on what
happens in January and February.