Patient-reported Hip Symptoms following Treatment with Proton Therapy for Prostate Cancer

Abstract

Purpose. We investigated patient-reported hip pain, stiffness, and physical function scores following proton therapy (PT) for prostate cancer.Patients and Methods. Between April 2012 and August 2012, men treated ≥18 months earlier with PT for localized prostate cancer were asked to participate in an institutional review board-approved study by answering the Western Ontario and McMaster Index (WOMAC) questionnaire for scoring patient-perceived hip symptoms. The questionnaire was returned by 325 patients treated at our institution; 290 patients completed all 24 questions and are the subject of this study. A higher WOMAC score indicated more problems. Patients had received PT doses ranging from 70-72 Gy (relative biological effectiveness [RBE]) at 2.5 Gy (RBE)/fraction or 78-82 Gy (RBE) at 2 Gy (RBE)/fraction using passively scattered protons. Using a Wilcoxon signed rank test, the post-PT normative scores for hip pain, stiffness, and functional difficulty were compared with the averages from general population-based values.Results. Median patient age was 67 (range, 50–90) years at the time of scoring their hip symptoms. Median follow-up was 36 (range, 18–66) months. The mean scores for hip pain, stiffness, and functional difficulty per the WOMAC questionnaire within the general population (age ≥50 years) were 1.48±0.18, 2.12±2.38, and 1.78±0.45, respectively. WOMAC scores from our 290 patients were significantly lower than those reported in the general public: pain 1.0±1.9 (p<0.0001), stiffness 1.5±2.2 (p<0.0001), and functional difficulty 1.1±1.8 (p<0.0001). In two subgroup analyses, WOMAC scores were not statistically different between patients who received 2.0 versus 2.5 Gy (RBE)/fraction, or 1 versus 2 PT fields per day.Conclusions. Patient-reported hip symptoms following PT for prostate cancer per the WOMAC questionnaire did not exceed the scores of the general population of males >50 years. There were no differences in hip symptoms between fraction size or number(s) of PT fields per day.