Background: The role of adjuvant radiotherapy (RT) following radical prostatectomy (RP) remains controversial. The aim of this study was to evaluate the benefit of adjuvant radiotherapy through PSA-level measurements.
Patients and methods: From January 1995 to September 1997, 31 patients with a prostate cancer were treated by bilateral pelvic lymph node sampling and radical prostatectomy. The tumour stage of all patients was pT3, pN0, M0. Seven weeks after surgery, radiotherapy was administered to the tumour bed using a 3D-conformal treatment technique. A total dose of 60 Gy was delivered in 6 weeks and 30 fractions. PSA values were measured before surgery, before radiation therapy and every three months after treatment.
Results: A cut-off level for PSA values of 0.3 ng/ml was defined. Twenty-four out of 31 patients had no measurable PSA before radiotherapy while 3 out of 31 patients had PSA-levels around the cut-off level. Four out of 31 patients, still had PSA-levels above the cut-off level seven weeks after surgery. The actual disease-free survival after 5 years was 87%. In 4 out of 31 patients, a relapse was observed after 18 to 40 months. In all 4 cases, postoperative PSA-levels had not reached the cut-off level of 0.3 ng/ml.
Conclusion: Despite postoperative radiotherapy, measurable PSA-levels 6 weeks after radical prostatectomy are risk factors for a PSA failure. Whether higher radiation doses can control these cases remains unclear.