Elucidating the mechanisms of lifestyle interventions in mitigating radiotherapy adverse effects: a scoping review.

The aim of this work was to review the literature on the mechanisms by which lifestyle interventions attenuate radiation therapy-induced side effects. A scoping review based on the Joanna Briggs Institute methodological framework was undertaken. MEDLINE, CINAHL and CENTRAL were searched up until 13 March 2024. Studies assessing the potential mechanistic effects of lifestyle interventions on outcomes in adult (>18 years of age) cancer patients undergoing radiotherapy, including any cancer type or intervention timing (before, during, after radiotherapy), were included. Data were extracted regarding study design, intervention characteristics and included outcome measures. Nine studies were included in the review. Study populations included patients with a range of cancers, including head and neck, prostate, breast, lung, lower gastrointestinal, rectal, pelvic and leukaemia. Lifestyle interventions consisted primarily of nutritional supplements, diets or traditional Chinese medicinal ingredients. Exercise programmes were also included. Those that were available involved either resistance training alone or in combination with aerobic exercise. The most common side effects included site-specific toxicity, with some interventions noting improvements to symptoms, alongside alterations to inflammatory cytokine and lymphocyte concentrations. Radiation-induced weight loss and frailty were noted, which may be prevented with interventions that target skeletal muscle metabolism. With more research to fully elucidate the potential mechanisms and consistent evidence of efficacy, lifestyle interventions may present promising non-pharmacological therapeutic options to alleviate some of the side effects of radiotherapy.