Although brachytherapy has not been considered a highly effective form of treatment for high-risk prostate cancer, it was shown to reduce prostate cancer–specific mortality (PCSM) compared with external beam radiation therapy (EBRT) alone in a recent large analysis.
Brachytherapy, which involves the precise placement of radiation sources directly at the tumor site, is typically used to treat low- and intermediate-risk prostate cancers. Its use is less common and more controversial in high-risk cases, partially due to early retrospective studies that found this modality to be associated with lower cure rates relative to EBRT, according to a statement issued by Thomas Jefferson University (TJU) in Philadelphia, Pennsylvania. The statement described the findings of the analysis, which were published in the International Journal of Radiation Oncology, Biology, Physics, and noted that poor brachytherapy technique might have contributed to these early unfavorable results.
Timothy N. Showalter, MD, an assistant professor in the department of radiation oncology at TJU Hospital in Philadelphia, and colleagues identified 12,745 men included in the Surveillance, Epidemiology and End Results (SEER) database who had been diagnosed from 1988 through 2002 with high-grade prostate cancer of poorly differentiated grade. The men had undergone EBRT alone (73.5%), brachytherapy alone (7.1%), or EBRT plus brachytherapy (19.4%). Median follow-up for all patients was 6.4 years.
The researchers found that the use of brachytherapy or EBRT plus brachytherapy increased from 5.1% in the 1988-1992 period to 31.4% in 1998-2002. Younger age, later year of diagnosis, urban residence, and earlier T-stage of tumor were significant predictors of use of brachytherapy or EBRT plus brachytherapy.
On multivariate analysis, treatment with either brachytherapy or EBRT plus brachytherapy was associated with significant reduction in PCSM compared with EBRT alone.
“This study contradicts traditional policies of using brachytherapy in just low- and intermediate-risk patients by suggesting there may instead be an improvement in prostate cancer survival for high-risk patients,” affirmed Showalter in the TJU statement.