Low dose-rate (LDR) brachytherapy to the prostate involves transperineal insertion of multiple (50-150) radioactive seeds.
- Iodine-125 (t1/2: 59.4 days), or
- Palladium-103 (t1/2: 17 days)
These are inserted into the gland, especially the peripheral zone where cancers usually arise, with concentration at the site of tumor based on biopsy or MRI. Side effects of incontinence, erectile dysfunction, diarrhea and urinary obstruction are usually short term, but bladder neck stricture can occur over the long term and cause difficulties in micturition, leading to a large residual bladder volume, as in this case.