Purpose: To evaluate 5-year prostate-specific antigen (PSA) relapse-free survival of transperineal permanent seed implantation (TPSI) in 118 patients with "low-risk" prostate cancer, that means stage cT1c-T2a, Gleason Score < 7, and initial PSA value < 10 ng/ml.
Patients and methods: From 04/1999 to 06/2002, a total of 118 patients underwent a mono-TPSI, using ultrasound-based preplanning and intraoperative verification by both ultrasound and conventional fluoroscopy as well as postoperative CT planning. Patients were monitored during the 1st year in 3-month intervals, and in 6-monthly intervals from then onward. Biochemical failure was defined according to ASTRO criteria with three consecutive PSA rises observed from a posttreatment nadir PSA value. The median follow-up was 48.9 months (range: 37.0-80.2 months). 114 patients were eligible, four patients were lost to follow-up.
Results: For the entire group, PSA relapse-free survival at 5 years was 94.7%, with six patients (5.3%) having a PSA relapse between 8 and 20 months after implantation. In the bNED patients (no biochemical evidence of disease), PSA values were < 0.2 ng/ml in 82.5% (94/114 patients), < 0.5 ng/ml in 13.2% (15/114 patients), < 1.0 ng/ml in 2.6% (3/114 patients), and < 1.5 ng/ml in 1.7% (2/114 patients). In summary, PSA values < 0.2 ng/ml, < 0.5 ng/ml and < 1.0 ng/ml occurred in 82.5%, 95.7% and 98.3%, respectively. Out of the six patients with recurrent disease, three had a local tumor recurrence only, and three developed distant metastases.
Conclusion: In low-risk prostate cancer patients, TPSI with intraoperative ultrasound-based treatment planning and fluoroscopy leads to excellent local tumor control and PSA relapse-free survival.