The clinician's guide to radiotherapy complications.

Abstract

Radiotherapy is one of the oldest cancer treatment modalities, used for over 100 years. As its efficacy has been steadily increasing due to the introduction of novel treatment methods, adverse events (AEs) still pose a major obstacle limiting the therapeutic benefits in some patients and negatively impacting treatment outcomes. In light of the technological progress, the focus has been shifted from improving the efficacy to safeguarding patients from the most severe AEs through improvements of safety and accuracy of radiation delivery. Currently, with radiation therapy being an effective treatment associated with frequent therapeutic success and leading to increased and prolonged survival, the problem of treatment‑related AEs is growing as there are numerous survivors whose health and quality of life may be adversely affected. Due to the limited access to radiation oncologists, patients presenting with AEs are often referred to other professionals for advice, and as survivorship prolongs, the AEs may aggravate current patient comorbidities or reveal undiagnosed diseases. Thus, it is important that doctors other than oncologists be familiar with the fundamentals of radiation therapy-related AEs and their management. In this review, we present the most common and severe AEs of radiotherapy associated with damage to the nervous, respiratory, cardiovascular, gastrointestinal, and urogenital systems. We also describe the pathogenesis of these AEs, and provide guidelines for prevention, risk assessment, diagnosis, and treatment. Novel findings and future perspectives in this field are also elucidated, including examples of ongoing clinical trials aimed not only at improving treatment outcomes but also at reducing the risk of radiotherapy complications in cancer treatment survivors.