Typically, radiation is considered for tumors that are Grade 3. Radiation sounds scary and in some ways it is. While the targeting technologies have improved a lot in the past 20 years, we are talking about radiating someone’s brain.
The fact is that while the radiologist will target the tumor or the bed around the tumor cavity, they will be sending radiation through some healthy brain as well. This is why there can be effects on the patient’s cognitive function after radiation, and while these effects are often considered “minor,” they can still impact a person’s life.
There are two different kinds of radiation therapy: Photon (the traditional kind) and Proton (the newer kind). The difference is simple to grasp. Photon beams keep going past the treatment area and proton beams stop at the treatment area. In both cases, healthy brain will be exposed to radiation as the beams go to the target area (entry dose), but with proton the healthy brain beyond the target will not be exposed to radiation. So with Proton, there is no “exit dose.”
So, everyone is using proton therapy, right? Well, no. The why is money. First, proton facilities are very expensive to build and they take up a fair amount space compared to photon. So, while the number of proton centers is growing rapidly, the number is probably under 40 in the US today—versus hundreds of photon facilities. And, second, because these centers are so expensive to build, they are more expensive to use. As a result, many insurance companies deny approval to use proton.
It is important to note, that Oligo patients have become more vocal in fighting insurance company denials of proton therapy, so if you are turned down, appeal the decision.
Final note: Whether proton or photon, it is important to be treated at a place that has a strong brain cancer program. This is even more important for proton therapy as many proton centers are relatively new and may not have “dialed in” the different targeting technologies (including Intensity Modulation Proton Therapy—IMPT—and pencil beam).