Temporary seed implants versus permanent seed implants for prostate cancer
Dear OncoLink "Ask The Experts,"
Do you know of any stats that show the relative effectiveness of high dose radiation (HDR) temporary seed implants versus the more traditional permanent seed implants? Is there any advantage that you know of in the HDR method?
Richard Whittington, MD, Associate Professor of Radiation Oncology at the University of Pennsylvania School of Medicine, responds:
The low dose rate is more effective against less aggressive tumors, and some think the high dose rate may be more effective against more aggressive tumors, although these tumors are more likely to spread and are usually treated with hormones as well as radiation. There is a real question whether high dose conventional external beam radiation with hormones is more or less effective or safer than high dose rate brachytherapy with hormones.
Very few centers do the high dose rate and they do it primarily for high-risk prostate cancer. Low dose rate (I-125 or Pd-103) is usually reserved for low risk cancers. The groups at the University of Wisconsin, Virginia Mason Hospital, and William Beaumont Hospital have reported their results with high dose rate therapy and it looks good in high-risk patients for local control, although these patients are also more likely to have trouble with distant metastases, and this risk is not affected.