Combinatorial radiation therapy for prostate cancer with seminal vesicle invasion

Abstract

Background. It seems advisable to investigate the feasibility of radiation therapy combined with hormone therapy to treat locally advanced prostate cancer. Combination of two ways to deliver ionizing radiation doses enables us to elevate a total tumor dose and to reduce radiation exposure to critical organs. However, the feasibility of combinatorial radiation therapy (CRT) in prostate cancer patients with seminal vesicle invasion remains insufficiently investigated. The number of studies focusing on this problem is still extremely small.Objective of this study is to evaluate the efficacy and toxicity of radiation therapy combined with hormone therapy for prostate cancer with seminal vesicle invasion.Materials and methods. From April 2016 to April 2020, 52 patients with prostate cancer (cT3bN0) received CRT at the clinic of the A.F. Tsyb Medical Radiological Research Center. The median patient follow-up was 29.7 months (from 11.9 to 58.4 months). The mean age of patients was 65.7 years. The initial mean level of PSA was 28.7 ng/ml. Fifty (96.2 %) patients were given radiation therapy together with hormone therapy.Results. The tolerability of CRT appeared satisfactory. Grade I acute radiation-induced reactions of the urinary tract occurred in 13 (25 %) patients; grade II ones - in 2 (3.8 %) patients. Grade I acute radiation-induced reactions of the gastrointestinal tract occurred in 11 (21.5 %) patients; grade II ones - in 1 (1.9 %) patient. Grade I late complications of the urinary tract were noted in 4 (7.7 %) patients; grade II ones - in 2 (3.8 %) patients. Grade I late complications of the gastrointestinal tract were noted in 2 (3.8 %) patients; grade II ones - in 3 (5.8 %) patients.The three-year cancer-specific survival rate was 97 %; the overall survival rate was 83 %. Eight (15.4 %) patients showed prostate cancer progression. Five (9.6 %) patients experienced cancer recurrence in the form of distant bone metastases. In 1 (1.9 %) patient, disease recurrence was associated with involvement of regional lymphatic collectors and distant inguinal lymph node metastases. Local recurrence was noted in 1 (1.9 %) patient. One (1.9 %) patient developed loco-regional recurrence with distant metastasis to bones. The three-year recurrence-free survival rate was 75.6 %.Conclusion. Our study demonstrates that CRT is highly effective in prostate cancer (cT3bN0) treatment while having an acceptable level of complications.