Radiotherapy-induced nausea and vomiting (RINV): antiemetic guidelines.

As many as 40-80% of patients undergoing radiotherapy (RT) will experience nausea and/or vomiting, depending on the site of irradiation. Fractionated RT may involve up to 40 fractions over a 6-8 weeks period, and prolonged symptoms of nausea and vomiting could affect quality of life. Furthermore, uncontrolled nausea and vomiting may result in patients delaying or refusing further radiotherapy. Nausea and vomiting are often underestimated by radiation oncologists. Incidence and severity of nausea and vomiting depend on RT-related factors (single and total dose, fractionation, irradiated volume, radiotherapy techniques) and patient-related factors (gender, general health of the patient, age, concurrent or recent chemotherapy, psychological state, tumor stage). Current antiemetic guidelines prescribe the emetogenicity of radiotherapy regimens and recommend the use of 5-HT(3) antagonists with or without a steroid for prophylaxis in moderately and highly emetogenic treatment (MASCC, ASCO, ASHP, NCCN). The new proposed guidelines summarise the updated data from the literature and take into consideration the existing guidelines. According to the irradiated area (the most frequently studied risk factor), the proposed guidelines are divided into four levels of emetogenic risk: high, moderate, low and minimal. They offer guidance to prescribing physicians for effective antiemetic therapies in RINV.