Purpose: To report long-term outcomes in terms of health-related quality of life (HRQoL) and survival of a dose-escalating radiotherapy protocol and to validate a new disease-specific HRQoL instrument.
Patients and methods: 189 consecutive men with prostate cancer were analyzed; 127 patients had T1-2 (1% T1, 66% T2) and 62 patients (33%) T3 tumors. The pelvic lymphatics were treated to a dose of 50 Gy by external-beam irradiation. The prostate dose was limited to 40 Gy using compensators. The prostate was treated to the total nominal dose of 70 Gy using high-dose-rate (HDR) brachytherapy. The fraction dose was 15 Gy in the McNeal zone (planning target volume [PTV] 1), while 8-9 Gy were applied in the entire prostate (PTV 2). The HRQoL of the 145 long-term survivors was assessed using the EORTC QLQ-C30 and a new prostate-specific instrument (PSM-G 1.0). The reliability of the instruments used and HRQoL scale scores were calculated. Uni-/multivariate analyses of variance were performed.
Results: At a mean follow-up of 6.5 years 86.3% of the patients were disease-free, and 78% were biochemically controlled. The mean Cronbach's alpha-values were 0.81 for the QLQ-C30, and 0.74 for the prostate-specific module. Univariate analyses of variance by T-stage, grading, prostata-specific antigen (PSA) status after therapy and adjuvant androgen suppression (AS) revealed that PSA elevation after irradiation and AS were associated with significantly diminished HRQoL. In multivariate analyses AS significantly lowered the HRQoL without survival benefit.
Conclusion: The described radiotherapy regimen represents a curative and well-tolerated treatment for localized prostate cancer. The HRQoL assessment with both instruments used was reliable. Adjuvant AS and PSA elevation were associated with diminished HRQoL.