Let’s hope that with the involvement of more centers, the situation will improve. It will take time in any case. I still think that protons are promising.

I suppose the truth is that I am angry with Loma Linda. Whether their excuse for not publishing a stream of really well documented data is laziness or whatever, as the only PBRT center in the US for a decade after the old Harvard PBRT system shut down, they had a moral obligation to document and publish their data in a well organized manner. They published one paper of (IMHO) very dubious quality, which you link to, and I think they should be ashamed of this.

The result is still that we really don’t have good, well-structured data on PBRT in treatment of prostate cancer, and we certainly have wasted the best part of 15 years as a consequence.

Patients received 74-75 grays (technically, grays or gray equivalents) to their prostates, as protons or protons + photons. 3.5 years ago, I got their standard dose, which had become 79.2 grays. I declined to join an experimental group getting more.

LL patients currently get 79 to 81 grays, in 44 treatment sessions, the dose being determined on an individualized basis, probably affected by the riskiness of their disease. Other centers have other formulas, and, for example, I heard that the Florida center also prescribes doses individually. An experimental group at LL is currently getting 60 grays in 20 sessions, i.e., hypofractionation.

I deplore publicity for PBT that relies on anecdotal evidence. You may be right in your suspicions, Mr. Sitemaster (we all need to be a bit skeptical), but I am inclined to a more generous assessment of LL. The failure to publish more data may be due to inertia and the “moving target” character of this therapy. (I’m referring to the science, not prostate position changes; that’s another story.)

One can perhaps infer that an honest sense of the advantages of proton beam therapy, based on less radiation outside the target area, has given PBT workers the confidence to change methodology, including, importantly, dose escalation to as much as 81 grays. More grays may kill the cancer more definitively; one can only hope that they do not increase side effects proportionately.

I think that a key word for PBT for prostate cancer is “promising.” As one iota of anecdotal evidence, I have personally done well after receiving PBT by a method that soon may be called crude. It created a high radiation zone around my prostate with less radiation remote from it, but there have been problems precisely planting that high radiation zone where it belongs. One or more U.S. centers are now implementing pencil beam scanning or spot scanning (synonyms), which ought to be an improvement.

One investigator wrote (in a slide presentation), “Protons are good. Whether the current state of the art is good enough is questionable. But can be much better. Achieving [what you see] = [what you get] is essential. And is equivalent to going from faith-based PT to faithful PT.”

Herb

But then that would be so simple and unscientific wouldn’t it?

Given the costs, wouldn’t it be incumbent on the proponents to show significant improvement over the older types of radiation therapy?

As positive on the proton as many prostate cancer patients seem to be, you just hope that it won’t ultimately turn out to be a gizmo poster child for common cancers.