One option of treatment of early prostate cancer is to implant the prostate with radioactive “seeds” (commonly referred to as “interstitial brachytherapy”). These seeds are made of either radioactive iodine or palladium and, once implanted, remain in the prostate permanently but their radioactivity decreases exponentially over time. They are inserted into the prostate via needles that enter through the skin between the scrotum and the anal opening under ultrasound guidance. Careful and precise maps are used to ensure that the seeds are placed in the proper locations in the prostate. Over the course of several months, the seeds give off radiation to the immediate surrounding area, killing the prostate cancer cells.
To be eligible for such an approach, patients have to fulfill certain criteria, e.g., T1-T2a disease, a prostate of moderate size, a PSA below 10 ng/ml, a low Gleason score and little in the way of urinary symptoms. The procedure is done under general or spinal anesthesia and rarely requires hospitalization. It may be used, also, after an external radiation therapy course to provide a “boost” dose to the prostate when indicated. Provided that patients who are appropriate candidates are properly selected, results of treatment of early cancer are equivalent to radical prostatectomy (surgery) or external radiation therapy. However, the possible adverse effects are qualitatively different between the three modalities. With radioactive seeds, there may be a lower likelihood of erectile dysfunction or urinary incontinence in comparison with surgery and of rectal problems in comparison with external radiation. The risk of urinary obstructive problems may be, however, slightly higher.