Lifestyle Interventions During Radiotherapy: A Scoping Review of Their Effects on Toxicity and Patient-Centered Outcomes

Background/Objectives: Lifestyle interventions may alleviate treatment-related toxicity and improve patient-centered outcomes during radiotherapy (RT). This scoping review mapped randomized evidence on lifestyle interventions delivered during RT, summarized reported outcomes, and identified evidence gaps. Methods: PubMed and Web of Science were searched for randomized controlled trials (RCTs) published from April 2016 to April 2026. Eligible studies included adults who received exercise, nutritional, psychological, combined, or multimodal lifestyle interventions during their RT treatment. Study characteristics, intervention details, and outcomes were charted and narratively synthesized. Results: Twenty-three RCTs were included. Exercise interventions were evaluated in 12 studies, nutrition in five, psychological in one, combined exercise-and-nutrition in two, combined nutrition-and-psychological in two, and multimodal interventions comprising all three components in one study. Breast, head and neck, and prostate cancers were most frequently represented. QoL, fatigue, and functional capacity were the most commonly assessed outcomes. Exercise interventions were most consistently associated with improvements in fatigue and functional capacity, whereas effects on QoL were less consistent. Nutritional interventions showed favorable findings for nutritional status and treatment-related toxicity. Psychological, combined, and multimodal interventions showed favorable findings for selected QoL, fatigue, nutritional, and psychological outcomes. Key evidence gaps included heterogeneous intervention protocols and outcomes assessment, limited evidence for non-exercise interventions and underrepresentation of several cancer populations. Conclusions: Lifestyle interventions delivered during RT may improve selected patient-centered and treatment-related toxicity outcomes. Exercise comprised the largest body of evidence, whereas other intervention types were less frequently evaluated. Heterogeneity across studies limits conclusions regarding optimal approaches. Further RT-specific studies using standardized intervention programs and comparable outcome measures are required to inform supportive-care delivery.