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?