Quality-of-life and toxicity in cancer patients treated with multiple courses of radiation therapy.

Background: Treatment of metastatic cancer patients with multiple repeat courses of radiotherapy has become more frequent due to their improved overall survival. However, very little is known about their long-term outcome. This analysis reports on the quality-of-life, hematologic toxicity, patient-reported experiences and satisfaction, and psychological distress of cancer patients treated with multiple repeat radiotherapy. Methods: All patients treated with ≥5 courses of radiotherapy between 2011 and 2019 at the Department of Radiation Oncology, University Hospital Zurich (USZ) were screened for this study. A course of radiotherapy was defined as all treatment sessions to one anatomical site under one medical indication. All patients completed two questionnaires: EORTC QLQ-C30 questionnaire for quality-of-life and a questionnaire evaluating psychological distress and patient-reported experiences. Hematologic toxicities were assessed via a recent blood sample. Results: Of n = 33 patients treated with ≥5 radiotherapy courses and being alive, 20 (60.6%) participated in this study. The most common primary tumor was non-small cell lung cancer (n = 14, 42.4%). The most common sites of irradiation were brain (n = 78, 37.1%) and bone metastases (n = 59, 28.1%). All participating patients reported that they had experienced a subjective benefit from multiple repeat radiotherapy and denied increased side effects in later radiotherapy courses. Yet, 45% (n = 9) of the patients reported an increase of psychological distress with increasing numbers of radiotherapy treatments. While global health status was stable, patients having received multiple repeat radiotherapy reported increased fatigue (p = <0.006). Blood analysis showed significantly reduced hemoglobin and lymphocyte levels compared to the healthy population (p = <0.03). Discussion and conclusion: Patient-reported experiences and satisfaction of long-term cancer patients treated with multiple repeat radiotherapy are positive. However, increased levels of fatigue and significantly reduced hemoglobin and lymphocyte levels were observed. These data indicate the need to further investigate the effects of multiple courses of radiotherapy in chronic cancer patients.