Patient- versus physician-reported outcomes in prostate cancer patients receiving hypofractionated radiotherapy within a randomized controlled trial

Purpose The risk of developing acute radiotherapy(RT)-induced side effects may increase with hypofractionated RT. To detect treatment-related side effects, patient-reported outcomes (PROs) might be more reliable than physician-reported outcomes. Therefore, we tried to evaluate the rate of agreement between urinary and gastrointestinal (GI) side effects and the prevalence of side effects reported by patients and by physicians. Methods Data from a randomized controlled trial (RCT) comparing two hypofractionated RT schedules were used. Urinary (nocturia, incontinence, frequency, dysuria, and urgency) and GI (obstruction, diarrhea, vomiting, nausea, bloating, hemorragia, and incontinence) symptoms measured by the EORTC QLQ-C30 and PR-25 were used for PROs. The same symptoms were scored by the physician using the Common Terminology Criteria Adverse Events v4.0. Outcomes were reported at baseline, end of treatment, month 1, and month 3. PROs and physician-reported outcomes were converted in two categories (0 = no symptoms; 1 = symptoms of any severity) and were correlated using the kappa (kappa) correlation statistics. Values below 0.40 were considered low agreement. In addition, the prevalence of symptoms was calculated. Results Data from 160 patients were used. The mean value for Cohen's kappa was 0.31 (ranging between 0.04 and 0.55) and 0.23 (ranging between 0.04 and 0.47) for urinary and GI symptoms, respectively. Except for three symptoms at baseline, all symptoms reported by patients were higher than those reported by physicians. Conclusion There is low agreement between symptoms reported by patients and physicians, with high rates of underreporting by the physician.