When I wrote last time, I was about to start steriotatic radiation therapy (SRT) at NIH to stop a tumor in (on) my brain. The treatments were uneventful: every morning for six weeks I went in first thing in the morning for my close encounters with MeV photons. The team of medical physicists and technicians followed a detailed procedure to ensure that the gamma-ray beams would be aimed at my tumor to millimeter accuracy. First they attached a metal ring ("halo") to my head. The halo was then bolted to the bed of the SRT machine. My head was immobilized within the halo by a mouthpiece attached to the front of the halo and Velcro straps looped over the top of my head; consequently I couldn't move my head or talk for the approximately half hour of the treatment. The placement of the halo relative to my head was checked by bolting a plexiglass helmut to the halo. A wood dowel with rulings was poked through holes in the helmut to measure the distance between the helmut and my head; the measurements were the same every morning to a fraction of a millimeter. The treatment consisted of five 'shots' during which the gamma-ray emitting gantry was rotated over an arc relative to my head; thus my head was irradiated by a series of thin fan beams that converged at the tumor. The dosage elsewhere was much lower, and thus, for example, I suffered no noticeable hair loss from the radiation. Since the bed on which I lay was moved before each shot, the medical team had to ensure that my head was in precisely the right spot. Consequently a frame with ruled rods (a 'cage') was bolted onto the halo before each shot, the lights were turned down and alignment lasers (green light) were turned on. The point where the halo was bolted to the bed was then moved slightly up or down or sideways until the alignment lasers hit the cage at precisely the right points. After the cage was removed, the team scurried out of the treatment room, a heavy door was closed (to protect them from stray radiation) and only then was the beam turned on.

I mention all these details for two reasons. First, the methodology was fascinating, at least to a physicist, and the attention to detail was reassuring, especially to a physicist with a healthy respect for radiation. As you can imagine, one of the physicists showed me how they planned my treatments, mapping the diagnostic CAT scans and MRIs to the SRT device. Another of the medical physicists showed me the bits and pieces of discarded devices that he has collected over the years (accelerators, collimators, filters, etc.). The other reason I describe the procedure is to give a sense how my morning stop at NIH turned into a ritual, a ritual based on a set of logical steps that became routine. Since I felt nothing in my head before, during or after being irradiated (actually, at the beginning of the first shot every morning I would see a brief flash of light in one eye resulting from some scatter onto my retina), the purpose of the routine often seemed remote.

To amplify the effects of the radiation, every night for six weeks I took Temodar, the chemo drug I took three years ago. Temodar causes nausea, and therefore I took an anti-nausea drug; both drugs slow down the GI tract, so I took a drug for that. Thus I had no noticeable side-effects from having my brain irradiated, but for six weeks I was 'aware' of the primitive functions of my GI tract. This use of Temodar has become standard since I was first treated with this drug: there are now slick brochures explaining how you, the patient, will be treated with this drug first to amplify the radiation and then as a chemo drug.

During this period that my brain was being irradiated, regions of my left leg were becoming progressively numb. There has never been a total loss of sensation, and definitely no loss of function. I had already felt this numbness at the time the brain tumor was discovered, but there had been no noticeable change in the scans below my neck, and the brain tumor obviously was the first concern. The plan was to wait a month after the radiation for the next MRIs, but as a result of the increasing numbness, I had a PET scan and an MRI of the spine. The only noticeable change in my spine was a region of swelling of the spinal cord. What does this swelling look like in an MRI? Normally the spinal cord appears as a thick solid line; over a few inches of my middle back the line is a little less solid and the edges are slightly less well-defined. Dr. Fine suspects the swelling results from tumor cells infiltrating into that part of the spinal cord; another doctor suggested that it might be a reaction to the radiation I had four years ago.

Regardless of whether this swelling is causing the new numbness, or whether the swelling results from tumor cells, the brain tumor and the growth of the neck tumor that was removed in August indicate that there are still active tumor cells in my central nervous system that need to be treated. Therefore Dr. Fine put me back on Temodar as a chemo drug-once a month I take the drug for 5 nights in a row at a much higher dosage than when I took Temodar to amplify the effects of the radiation. I have finished one cycle; I will have new scans just before the beginning of the 3rd cycle.

Other than the side-effects of the Temodar-by the end of the week I take the drug my GI tract is messed up and I am tired both from the Temodar and from the insomnia it (or all the other drugs) induces-the major symptom of my condition is the numbness in my left leg. For example, while walking I feel as if my shoe is full of sand.

Psychologically I am of course aware that the episodes requiring medical intervention are becoming more frequent, and that containment of the ependymoma has moved into a more active phase. Nonetheless, I get into work, except when I have medical appointments, or Jewish holidays, or family events…