2nd dose of radiation.

Good news, my red blood cell count did not drop last night, which probably means the internal bleeding has stopped. Also, my platelet count was 13 this morning, which is the highest it has been in a month, and anything over 10 is acceptable. They gave me another dose of platelets this evening because a normal count is up around 200 to 400, so they are planning on continuing to give me platelets until the count is above 50.

I had my second dose of irradiation today. I learned more about the machine. Doug asked me what it used as a source for the gamma radiation. It turns out that it is a linear accelerator, so it does not use a source at all. A linear accelerator takes electrons and accelerates them to very high speeds. Even my non-sciency friends may have heard about the linear accelerator at CERN where they recently discovered the Higgs Boson. This is a bit smaller, but the same idea. The electrons then hit a metal target, which changes them to photons. The photons are filtered to wavelengths that are wanted. When people talk about gamma radiation, they are talking about the wavelength. Gamma radiation are photons, just as visible light is, but because the wavelength is different, they have different energies. After it passes the filters, there are number of reflectors, called leaves, which shape the beam and bounce it toward the target organ. The leaves can move to change the shape of the beam dynamically, as the whole thing rotates around the person. This focuses the correct amount of radiation in the target organ while keeping the amount of radiation in the nearby organs low enough so as not to damage them. Because my spleen is pretty large and there is not much in the way from the front and the back, they just do two half-doses and do not do a dose from the side, where they might hit my kidneys.

My dose (per treatment) is one grey (Gy) and I have 9 treatments scheduled, but we may not do all the treatments depending on how my spleen responds. 1 Gy equals 100 rad, and rad stands for radiation absorbed dose. This is a pretty large dose, in that you would not want this much radiation if you were not getting treatment - it is about the radiation in 5 million bananas, or 20 times the safe limit for a radiation worker. However, as a treatment dose, it is about as low as you can have, with typical treatment doses going up to 60-80 Gy.

I have felt pretty good all day, and no nausea from the radiation. Also, I got lemon meringue pie for dessert, so life is just fine.