PBRT vs. IMRT — patients can now enroll at more sites


The “New” Prostate Cancer InfoLink has consistently encouraged newly diagnosed patients who are thinking about radiation therapy as treatment for low- and intermediate-risk, localized prostate cancer to consider enrolling in the ongoing, randomized, Phase III clinical trial known as the PARTIQoL trial.

This trial has been carefully designed to compare the outcomes of men treated with either proton beam radiation therapy (PBRT) or modern, intensity-modulated (photon beam) radiation therapy (IMRT). The goal is to determine whether or not there are real benefits to treating such men with PBRT as compared to IMRT in terms of their overall outcome (elimination of the cancer; avoidance of side effects; and improved quality of life).

In our view this is a very important trial indeed. It has long been claimed by the advocates for PBRT that PBRT is indeed safer for patients than IMRT and leaves them with a higher quality of life … but we need to complete this trial as soon as possible to bring clarity to this issue once and for all.

Four new centers are now enrolling patients into this trial — in Chicago, Houston, central New Jersey, and St. Louis (in addition to the original two centers in Boston and Philadelphia). So a total of six centers are enrolling patients, and another three centers are expected to start enrolling patients in the near future. (We will update you on that information as soon as these three additional centers come on line.)

Here is the full list of centers currently enrolling patients:

  • Northwestern Medicine Central DuPage Hospital in Chicago, IL (contact: William Hartsell, MD; tel: 630-821-6492; e-mail: william.hartsell@chicagocancer.org)
  • Massachusetts General Hospital in Boston, MA (contact: Jason Efstathiou, MD, DPhil; tel: 617-726-5866; e-mail: jefstathiou@partners.org)
  • The University of Texas M. D. Anderson Cancer Center in Houston, TX (contact: T. J. Pugh, MD; tel: 713-563-3619; e-mail: tpugh@mdanderson.org)
  • ProCure New Jersey / CentraState Medical Center in Somerset and Freehold, NJ (contact: Oren Cahlon, MD; tel: 732-357-3600; e-mail: ocahlon@prapa.com)
  • The University of Pennsylvania in Philadelphia, PA (contact: Justin Bekelman, MD; tel: 215-662-7266; e-mail: bekelman@uphs.upenn.edu)
  • Washington University in St. Louis, MO (contact: Jeff Michalski, MD; tel: 314-362-8566; e-mail: jmichalski@radonc.wustl.edu)

The “New” Prostate Cancer InfoLink particularly asks patient advocates and prostate cancer support group leaders to bring this trial to the attention of any newly diagnosed patient who lives in an area near to the six available recruiting centers.

We really do need to know whether PBRT can offer better overall outcomes than IMRT to patients electing radiation therapy for localized prostate cancer, if that is in fact the case. And if PBRT really can’t provide better overall outcomes, then we need to know that too. It seems highly unlikely that the majority of patients interested in radiation therapy as their first-line form of treatment have anything to lose from enrolling in this trial because no current evidence can tell us with accuracy which of these two forms of localized radiation therapy is better than the other.

2 Responses

  1. Glad to see this trial, but some concerns.

    I wish they were focusing only on intermediate-risk patients or were stratifying so that low-risk patients would be randomized in equal numbers to the IMRT and PBRT arms of the study. Hopefully, as this trial is fairly large at 400 patients, each arm will get an equal number of low-risk patients and thereby avoid the risk that results would be confounded by disproportionate assignment of low-risk patients. (Low-risk is somewhat liberally defined as a PSA of up to 19.x – that is, less than 20, along with stage up to T2b and GS <=6.)

    I’m wondering if the description at the link got this line of the eligibility part of the trial description right: “Gleason score ≤ 6 if PSA < 20 or Gleason score 3 + 4 = 7 or 4 + 3 = 7 if PSA < 20” That is redundant as they could have simply stated “Gleason less than 8 and PSA less than 20” for all comers.

    Imaging for daily targeting (as contrasted to initial planning) and patient positioning technologies are not specified or restricted, and these technologies are clearly very important. I have fairly good confidence that this will not be a confounding issue because I get the sense the centers selected know what they are doing. Any thoughts on that?

    I'm curious how the truly low-risk (GS <= 6, PSA <= 10, Stage <= T2a) will be advised about the option of active surveillance before enrollment. M. D. Anderson) has a well-known active surveillance program, but I'm not aware of prominent programs at any of the other centers, and two of them are associated with Dr. William Catalona, who vehemently opposed active surveillance for years; I'm not sure of his present position. Those two centers are the University of Washington at St. Louis and Northwestern University. Has anyone gone through the trial briefing process who could comment on this?

  2. Dear Jim:

    You wrote that ” (Low-risk is somewhat liberally defined as a PSA of up to 19.x – that is, less than 20, along with stage up to T2b and GS <=6.)"

    Actually your statement is incorrect. The criteria specified in the inclusion criteria, and as written above, is an extremely accurate statement of the inclusive definition of all low- and intermediate-risk patients. The low-risk patients would still need to have a PSA of 10 or less; the intermediate-risk patients could have a PSA as high as 20. However, this in no way implies that a low-risk patient could have a PSA higher than 10 ng/ml.

    On the other hand, I think you may be right about the rather confusing statement that “Gleason score ≤ 6 if PSA < 20 or Gleason score 3 + 4 = 7 or 4 + 3 = 7 if PSA < 20”. I'm tempted to think that maybe that should have read as "Gleason score ≤ 6 if PSA < 10 or Gleason score 3 + 4 = 7 or 4 + 3 = 7 if PSA < 20”.

    Dr. Catalona hasn’t has anything to do with Washington University for the best part of 20 years now … and my understanding is that they weren’t exactly on the best of terms with each other when he left.

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