As I learn more it seems that the Proton therapy is not as precisely accurate as the Tomotherapy. What the result of this is, I have no idea.
Cindy's description sure helps.
Well the result of more accurate photon delivery via the Tomotherapy should be a lessening of the unwanted side effects of radiation in the first place. You must understand that with photons the beam starts to scatter and lose its energy as soon as it contacts the skin. This requires the dosage to be escalated as the prostate is about
as deep in your body as it is possible for an organ to be. So in order for the prostate to receive an effective dose of radiation (effective meaning, kill the cancer) the level has to be pretty high as only 60% or so of the actual dose reaches the prostate. The rest irradiates the surrounding tissue and some exits the body entirely. The current theory is to deliver small managable doses of photons to the area to be treated as it is the total accumulated dose that provides the cure. It is also why photon and protons are delivered over time, say 40-45 treatments. If you were to deliver the total radiation dose equaling 76-79 Gy (gray) you would die outright of rad poisoning. 10-20 Gy administered full body at once is usually a fatal dose.
With Protons over 90% of the energy is delivered to the tumor site, in the case of the prostate it is delivered 3 dimensionally also called conformal treatment using a lens called a bolus that is made specifically for YOUR prostate by the treating team. Scatter is non-existant and no radiation passes through the body and unwanted radiated tissue is kept to a minimum. In fact one of the possible benefits of Protons is that a typical treatment regimen will include the margins of the prostate where cells that have already escaped may be lurking. Accuracy is generally within 1 millimeter in any case.
Actually I think a truer statement would be that Tomotherapy treatment is trying to mimic the delivery system of Protons in order to increase the accuracy of the treatment and minimize side effects, rather than the other way round.
You should feel confident in choosing either modality for treatment. I personally, am choosing Protons.
It is tough to have to choose, isn't it? It is not like the Dr. will help with this decision and you never can be entirely sure that what you choose will be the best for you and present a cure, which is what we all seek. Take care and please if you have any more doubts, questions or whatever feel free to ask.