Proton therapy for prostate cancer: The initial Loma Linda University experience

Purpose: We analyzed results of conformal proton radiation therapy for localized prostate cancer, with emphasis on biochemical freedom from relapse. Methods and Materials: Analyses were performed for 1255 patients treated between October 1991 and December 1997. Outcomes were measured on primarily in terms of biochemical relapse and toxicity. Results: The overall biochemical disease-free survival rate was 73%, and was 90% in patients with initial PSA less than or equal to4.0; it was 87% in patients with posttreatment PSA nadirs less than or equal to0.50. Rates dropped with rises in initial and nadir PSA values. Long-term survival outcomes were comparable with those reported for other modalities intended for cure. Conclusions: Conformal proton radiation therapy at the reported dose levels yielded disease-free survival rates comparable with other forms of local therapy, and with minimal morbidity. Dose-escalation strategies are being implemented to further improve long-term results. (C) 2004 Elsevier Inc.