Comparative evaluation of radiation treatments for clinically localized prostate cancer: an updated systematic review

Radiation therapy is one of many treatment options for patients with prostate cancer.

To update findings on the clinical and biochemical outcomes of radiation therapies for localized prostate cancer.

MEDLINE (2007 through March 2011) and the Cochrane Central Register of Controlled Trials (2007 through March 2011).

Published English-language comparative studies involving adults with localized prostate cancer who either had first-line radiation therapy or received no initial treatment.

6 researchers extracted information on study design, potential bias, sample characteristics, interventions, and outcomes and rated the strength of overall evidence. Data for each study were extracted by 1 reviewer and confirmed by another.

75 studies (10 randomized, controlled trials [RCTs] and 65 nonrandomized studies) met the inclusion criteria. No RCTs compared radiation therapy with no treatment or no initial treatment. Among the 10 RCTs, 2 compared combinations of radiation therapies, 7 compared doses and fraction sizes of external-beam radiation therapy (EBRT), and 1 compared forms of low-dose rate radiation therapy. Heterogeneous outcomes were analyzed. Overall, moderate-strength evidence consistently showed that a higher EBRT dose was associated with increased rates of long-term biochemical control compared with lower EBRT dose. The body of evidence was rated as insufficient for all other comparisons.

Studies inconsistently defined and reported outcomes. Much of the available evidence comes from observational studies with treatment selection biases.

A lack of high-quality comparative evidence precludes conclusions about the efficacy of radiation treatments compared with no treatments for localized prostate cancer.

Agency for Healthcare Research and Quality.