IMRT shows rapid uptake but fails to outperform CRT
medwireNews: Intensity-modulated radiotherapy (IMRT) is equivalent to conventional conformal radiotherapy (CRT) in terms of morbidity and cancer control outcomes in the treatment of prostate cancer after radical prostatectomy (RP), shows a study published in JAMA Internal Medicine.
The clinical equivalence of the two techniques, together with the greater cost of IMRT, raises questions about the value of the newer approach and highlights the need for formal cost-effectiveness analysis, say Ronald Chen (University of North Carolina Hospitals, Chapel Hill) and fellow authors.
Chen's team used the national Surveillance, Epidemiology, and End Results-Medicare-linked database to identify patients who received radiotherapy within 3 years of undergoing RP for prostate cancer.
Between 2002 and 2007, 457 men received IMRT and 557 received CRT. "Use of IMRT increased from zero in 2000 to 82.1% in 2009," note Chen et al.
The team then compared various outcomes between the two treatment groups, using propensity scoring to minimize confounding by baseline differences.
Rates of gastrointestinal and urinary complications were similar in the two groups, as were rates of erectile dysfunction, report Chen et al. The frequency of subsequent cancer therapies - indicating recurrence - was also similar between groups, while sensitivity analyses indicated equivalent magnitude and precision of therapeutic effect both immediately after surgery and after 2 years of follow up.
The researchers say that their study reveals the rapid adoption of IMRT in favor of CRT "despite a relative lack of comparative effectiveness data." The reason for the rapid increase "may be related to expectations by physicians and patients of a reduction in treatment morbidity from IMRT or in part because of higher reimbursement for the use of IMRT," they suggest.
This study, however, "shows that these expectations may not be based in clinical reality," they write, adding: "We found no significant difference in the present study in any outcome between the 2 techniques for postprostatectomy radiotherapy."
Noting that IMRT is more expensive than CRT, the team concludes that the potential clinical benefit of IMRT compared with CRT in this setting is unclear.
They write: "Our results provide new and important information to patients, physicians, and other decision makers on the currently available evidence regarding the outcomes of different postprostatectomy radiation techniques."
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By Joanna Lyford, Senior medwireNews Reporter