• More comparative effectiveness goodness

    In this week’s JAMA Internal Medicine, “Comparative Effectiveness of Intensity-Modulated Radiotherapy and Conventional Conformal Radiotherapy in the Treatment of Prostate Cancer After Radical Prostatectomy“:

    Importance  Comparative effectiveness research of prostate cancer therapies is needed because of the development and rapid clinical adoption of newer and costlier treatments without proven clinical benefit. Radiotherapy is indicated after prostatectomy in select patients who have adverse pathologic features and in those with recurrent disease.

    Objectives  To examine the patterns of use of intensity-modulated radiotherapy (IMRT), a newer, more expensive technology that may reduce radiation dose to adjacent organs compared with the older conformal radiotherapy (CRT) in the postprostatectomy setting, and to compare disease control and morbidity outcomes of these treatments.

    Design and Setting  Data from the Surveillance, Epidemiology, and End Results–Medicare–linked database were used to identify patients with a diagnosis of prostate cancer who had received radiotherapy within 3 years after prostatectomy.

    Participants  Patients who received IMRT or CRT.

    Main Outcomes and Measures  The outcomes of 457 IMRT and 557 CRT patients who received radiotherapy between 2002 and 2007 were compared using their claims through 2009. We used propensity score methods to balance baseline characteristics and estimate adjusted incidence rate ratios (RRs) and their 95% CIs for measured outcomes.

    Some patients benefit from radiation therapy after a prostatectomy. But the original method, conformal radiotherapy (CRT) required a fairly large amount of radiation. Intensity-modulated radiotherapy was supposed to fix this. It cost a lot more, though. Nonetheless, it went from being non-existent in 2000 to more than 82% of radiation therapy in 2009.

    Is it better though? Does it reduce morbidity and mortality? Wouldn’t it be nice to know?

    That’s what this study did. It used existing data to look at what happened to patients who received each type of therapy for three years after their prostatectomies. What did they find? There were basically no difference in the adjusted number of events between IMRT and CRT for each 100 person years with respect to the diagnosis of gastrointestinal events (9.4 vs. 9.9), urinary incontinence (11.8 vs. 12.0), or erectile dysfunction (11.7 vs. 13.8). There was also no significant difference in treatment for recurrent disease.

    So why are we paying so much more for IMRT? Why is it being used in more than 80% of cases?

    @aaronecarroll

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    • I’m a radiation oncologist, and I can give a little insight on why it is used.

      IMRT allows the radiation to be “bent” and curve around critical structures, specifically the rectum and the bladder, in an effort to reduce toxicity, while allowing escalation of dose. In “intact” prostate cancer (where the prostate has not been removed), IMRT allowed the dose to be escalated to the point where the treatment is equivalent to surgical removal of the prostate. This is necessary, because at curative doses for intact prostate cancer (75.6 to 81 Gy), without IMRT, the risk for late complications (specifically rectal bleeding) increases substantially. There has not been a randomized control trial, but historical controls (and studies like the one you have cited) have indicated that this is the case – that late rectal bleeding and other GI morbidities have been reduced, while biochemical control has increased, and I don’t think most oncologists question the benefit (although many people question the high reimbursement, but that’s a different discussion).

      Now, in the case of “adjuvant” radiation after surgical removal of the prostate, the dose that people treat to (60-70 Gy) is lower than in intact cancer. The thought was that in patients who had surgery, the tolerance to critical structures such as the bladder neck and rectum may be compromised, and toxicity could occur at lower doses than seen in intact cases. However, I don’t think this has been borne out. The adjuvant RT trials (where they compared RT vs no RT in patients with high risk disease) did show a difference in acute toxicity, however there was no difference in late toxicity. So, if radiation itself compared to nothing didn’t lead to increases in toxicity, it makes sense that “fancier” radiation would also not show a benefit, and the study results don’t surprise me.

      However, there is a dosimetric benefit (we can show that the dose to the rectum, bladder, and penile bulb is lower with IMRT), and that’s what leads people to continue to use it, along with the higher reimbursement. If I was treating myself, I’d use IMRT. I don’t think the higher cost is justified, and frankly, if the reimbursement was decreased to the same level that 3D treatment gets reimbursed, I’d still offer it to patients. It’s theoretically better, the plans look better, and there is far less integral dose. As for why it’s reimbursed so high, again, different discussion.

      Simul, M.D.

      • Thanks for this. But I still don’t get why you don’t see different rated of adverse reactions if this is the case.

      • “In any case, it’s theoretically better, it’s getting easier to use and plan and deliver the treatment. I don’t see the need for the higher reimbursement, but I’d want it done for myself. Say a new surgical technique reduces blood loss by a few cc’s. It won’t make the outcomes better, no improvement in surgical mortality or length of hospitalization, but it’s a better procedure. This is just a better technique – agree it shouldn’t reimburse higher, but it’s dosimetrically better. It used to take much higher labor and technical support to treat, but now it is very easy to do.”

        I disagree for several reasons:

        1. Newer treatments inevitably have been studied less, and proceduralists have less experience with them. The results are therefore less predictable. Take laparoscopy, for example. Many older surgeons still use it infrequently, so for all but the most common operations (laparascopic cholecystectomy, appendectomy, for example) you’re better off choosing a surgeon who has more extensive experience with the certain procedure (laparoscopic roux-en-Y in bariatric surgery, for example).

        2. What we want for ourselves as physicians, being educated, well-insured, and financially secure, generally, is not necessarily the same as we should suggest for our patients, who may not have a similar perspective. The marginal cost would usually means little to us, so we’d just as soon receive less radiation.

        3. You don’t know that something is better until you study it. In the majority of cases, new techniques are poorly studied before extensive use. And in even fewer is good comparative effectiveness research done before practitioners start changing their technique.

    • Some studies do show this, these are just two institutional reports:
      http://www.sciencedirect.com/science/article/pii/S0360301600014747
      http://www.sciencedirect.com/science/article/pii/S0167814008003939

      But, the rate of toxicity is low to begin with:
      http://www.sciencedirect.com/science/article/pii/S0360301607002416

      And so showing a benefit might be difficult. Also, the study above doesn’t account for 1) image guidance techniques (which is a daily CT, which in studies indicates better biochemical control because the daily hit rate is higher) 2) centers that use rectal balloons or other immobilization devices and most importantly 3) doses (places using IMRT go to higher doses – 66-70 vs 60 – and maybe this is why the toxicities equalize).

      In any case, it’s theoretically better, it’s getting easier to use and plan and deliver the treatment. I don’t see the need for the higher reimbursement, but I’d want it done for myself. Say a new surgical technique reduces blood loss by a few cc’s. It won’t make the outcomes better, no improvement in surgical mortality or length of hospitalization, but it’s a better procedure. This is just a better technique – agree it shouldn’t reimburse higher, but it’s dosimetrically better. It used to take much higher labor and technical support to treat, but now it is very easy to do.

      • Simul,
        I state below collegially.

        When I see declarations like, “its theoretically better,” I also think of below in the same manner:

        * routinely using HRT (WHI)
        * suppressing VPBs post-MI (CAST)
        * doing internal carotid artery bypasses (EC-IC study)
        * using alpha blockers to prevent stroke (ALLHAT)
        * giving estrogen to men with CAD (CDP)
        * giving high-dose GIK infusions in the CCU (CREATE)
        * using perioperative beta blockers (POISE)
        *COURAGE and stable angina
        *OAT–post MI PCI
        *Vertebroplasty
        *Knee surgery for DJD

        You get the idea. What glitters is often not gold.

        Brad

      • Dr. Parikh, I want to see if I understand the basics of what you said. If we look at the problem as a tennis ball that is the good tissue the radiation must pass through and a walnut in the center as the cancer, then is the development of radiation therapy as follows.

        Early on radiation was fixed coming from one site or a few where the beam was concentrated on the walnut, but similarly concentrated on the good tissue causing high damage.

        Next step: The beams move via computer so that they are concentrated on the walnut, but by going in different directions through the good tissue in lower doses they do less damage.

        IMRT by bending the radiation is able to concentrate on the walnut further and diffuse the damage around the tennis ball to a greater extent causing less damage to the surrounding structures.

        I think in your statements you have answered most of my questions, but I want to be sure.

        Questions: If the above, a simplistic representation is so, early on was the maximum radiation dose determined by the damage caused to good tissue or to the tumor?

        Are high dose radiation pellets plus a lesser dose of external radiation doing basically the same thing as IMRT by mostly working from the inside out?

        How much more radiation can be provided with IMRT to the target than normal radiation? Is the dose increased? Does this leave room for radiation treatment should there be a recurrence in a limited area?

    • I suspect, based on anecdotes not evidence, that the reimbursement pattern here is pretty common. Initially a new treatment is very difficult to do, only a few specialists have the training to perform it, and the reimbursement rate is set to a high level. Over time, experience, practice, and introduction of new technology makes the procedure much easier and quicker, but the reimbursement rates stay high out of inertia. I think cataract surgery would be a good example of this. As this became a more-or-less routine procedure, reimbursement rates eventually came down, but it took a long time.

      It is interesting to compare this with procedures that are not covered by health insurance. My impression is that costs for Lasik came down much more quickly than those for cataract surgery.