Prediction of Genitourinary Tract Morbidity after Brachytherapy for Prostate Adenocarcinoma

Objective: To investigate whether preoperative genitourinary variables in patients undergoing brachytherapy for localized prostate adenocarcinoma could predict postoperative genitourinary tract morbidity. Patients and Methods: We retrospectively reviewed medical records of 105 men who received either iodine 125 or palladium 103 radioactive seed implants with or without external beam radiotherapy or hormone blockade from January 1, 1998, through December 31, 2000, at the Mayo Clinic in Jacksonville, Fla. Patients with one or more of the following were classified as having a high risk of postoperative genitourinary tract morbidity: American Urological Association symptom scores greater than 15, maximum urinary flow rate less than 10 mL/s, postvoid residual urinary volume greater than 100 mL, or prostate volume greater than 40 cm³. Of the 105 men, 59 (56%) were classified as high risk and 46 (44%) as low risk. Mean follow-up after brachytherapy was 23.6 months. Modified Radiation Therapy Oncology Group scores were used to assess postoperative genitourinary tract morbidity. The term significant genitourinary tract morbidity was applied to patients with a Radiation Therapy Oncology Group grade of 3 or 4 after at least 6 months of follow-up. Results: Significant morbidity occurred in 37% of high-risk vs 15% of low-risk patients (P=.006). In high-risk patients, transurethral resection or incision of the prostate was required in 5 patients, urethral dilation in 4, direct-vision internal urethrotomy in 1, and placement of a suprapubic catheter in 1. In low-risk patients, transurethral incision of the prostate was required in only 1 patient. Urinary flow rate was a significant individual predictor of postoperative morbidity (P=.03). Conclusions: A combination of urinary flow rate, prostate volume, postvoid residual urinary volume, and American Urological Association symptom score can help identify patients with underlying voiding dysfimction. Urinary flow rate was a statistically significant predictor of genitourinary tract morbidity after brachytherapy for localized prostate adenocarcinoma. Patients and physicians should consider these factors before a patient decides to undergo brachytherapy.