Relative value of 3D-CRT, IMRT, and PBRT in prostate cancer published in JAMA

In February we reported on a presentation by Sheets et al. at the Genitourinary Cancer Symposium. The presentation addressed the comparative effectiveness and safety of  3D conformal, intensity-modulated, and proton beam forms of radiation therapy (3D-CRT, IMRT, and PBRT, respectively).

The full, peer-reviewed data from this study have now been published in the Journal of the American Medical Association (JAMA). The data published by Sheets et al. continue to suggest that:

  • IMRT was the most widely used form of radiation therapy in the management of prostate cancer in 2008.
  • Prostate cancer patients treated with IMRT as compared to 3D-CRT were
    • Less likely to have gastrointestinal morbidities post-radiation
    • Less likely to have fractures of the hip post-radiation
    • More likely to have erectile dysfunction post-radiation
    • Less likely to need additional cancer therapy
  • Prostate cancer patents treated with PBRT as compared to IMRT were
    • More likely to have gastrointestinal morbidity post-radiation

A commentary on this article on the Reuters web site carries third-party views on this article from a number of different specialists. As yet, however, we have seen no refutation of or other commentary about these data from any member of the PBRT community.

3 Responses

  1. Mike:

    I recently cited this page on the Inspire blog and received the following response (I should add that the poster may have a bias since he received proton beam therapy at UFPTI):

    “This so-called ‘study’ was DOA. It compared apples and oranges, using over 6,000 men from various places across the US for the photon studies, and 600+ men from one center for proton. They knew nothing about the state of the men pre-treatment (Gleason, PSA, etc.), nor did they know in fact whether the so-called side effects had anything to do with their treatment. They relied exclusively on statistics from Medicare, assuming that if a man had a colonoscopy after being treated than he must be having gastro-intestinal side effects from his radiation. Absurd. This study has since then been debunked by various experts who bring actual facts to the table. At UFPTI, for example, their 5-year stats are unbelievably good. …”

    Unfortunately, I am unable to review more than just the abstract at JAMA; have you looked at the whole paper and can you comment? The subject of proton beam vs. IMRT comes up frequently in advocacy circles, and I have cited this paper more than once in the past few months.

    I have asked the poster to provide citations for the debunkers; of course, we are always circumspect of sources that have a self-interest, especially an economic interest!

  2. Rick:

    The relative value of proton beam radiation therapy to other forms of radiation therapy is never going to be resolved until the radiation oncology community stops squabbling within its own ranks, puts the good of patients first, and actually carries out a large, meaningful, prospective study (preferably randomized) that compares (at a minimum) the current “best standard” form of PBRT to the current “best standard” form of IMRT in men with (ideally) intermediate- and high-risk localized disease (and low-risk disease among men 0f less than 65 years).

    Frankly, all other studies are merely hypothesis-generating. Having said that, I remain appalled that Loma Linda has utterly failed to provide any really compelling data from their nearly 20-year experience. The short-term data from the newer centers has not (as far as I can see) offered us any suggestion that PBRT is any “better” (in terms of outcomes or side effects) than the modern, highly tragted forms of IMRT.

    I have not seen the full text of the JAMA article. However, it is hardly surprising that anyone from the PBRT community (patient or professional) accepts the data presented in that paper. It is a purely retrospective review; it is based on an analysis of Medicare claims; and it is, therefore, not “compelling.” On the other hand, it’s what we’ve got. Just saying that it isn’t true is even less compelling. By no means is it DOA.

  3. Thanks for your observations, Mike. While I would wholeheartedly agree with you, it may be hard to convince someone that has spent $50,000 on treatment that PBRT is not superior, never mind the Institute that provides it!

    The “debunk” citation subsequently provided refers to letters to the editor published in JAMA on 8/12.

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