While Novallis as a radiotherapy machine is typically used in FSR applications of around 25-30 days, it has the capability of doing one shot. My understanding is that it would require a GK like head frame instead of the softer mask, but I don't know that for certain. GK and CK would typically have a one dose protocol of around 12 GY and that is based on what level studies show is required to have a biological effect. This is not a machine issue, but a protocol based on treatment effectiveness, so I strongly doubt Crystallady got a significantly different dose with Novalis.
I'm very happy that she had a positive experience with the machine , the team, and with her preliminary results. All of the machines are capable of effectively treating AN's but there are differences in accuracy which influence how the respective teams use them. The reason the vast majority of folks get a 25-30 day protocol is because it has lower accuracy than either CK or GK. The lower per treatment dose over a longer period allows for better outcomes and less risk of damage to healthy tissue. GK ( 1 dose only) and CK ( 1-5 dose for AN) deliver a much higher per treatment dose in less days simply because they are more accurate and can do so with less risk than Novalis. In short, there is a reason it is rare to see a one dose protocol with Novalis. Again, I'm thrilled that her treatment has worked so well for her, but in my opinion, if you treated a 100 patients on a one dose protocol with all three machines there would probably be some outcome differences with Novalis compared to the other two. It's a question of odds and probabilities. I can't remember where we "disagreed" as she referenced on her post, but I'm assuming it is on this issue of accuracy. If so, we will agree to disagree
. Based on the studies I've read and probably more important, the opinions of radiation oncologists who have used all three, I think the differences in accuracy are documented and are what they are.
Mark
