MASCC Antiemetic Recommendations in Radiotherapy

New recommendations regarding the use of antiemetics in radiotherapy given in the Multinational Association of Supportive Care in Cancer (MASCC) International Consensus Conference 2004 in Italy have recently been published by Maranzano et al.

Although not as intense in severity and frequency as nausea/vomiting in chemotherapy, radiotherapy-induced emesis (RIE) is an event not to be neglected. Nausea and/or vomiting is a common adverse effect experienced by as many as 40% of patients undergoing radiotherapy, potentially affecting the quality of life and even the efficacy of tumour control of a significant proportion of cancer patients. Panel participants comprised of 23 oncology professionals from 5 continents and 9 international oncological associations were selected by the MASCC for the guideline development process on prevention of emesis induced by chemotherapy and radiotherapy, with pertinent information published literature as of March 2004 carefully reviewed. Both the MASCC level of scientific confidence and level of consensus, and the American Society of Clinical Oncology (ASCO) type of evidence and grade for recommendation were adopted. With the irradiated area being the only risk factor considered for the incidence and severity of RIE, 4 emetic risk level categories (high, moderate, low and minimal) are used in the new guidelines. Total body irradiation is classified at high risk (possibility more than 90%), upper abdomen irradiation at moderate (possibility 60-90%), lower thorax, pelvis, cranium (radiosurgery) and craniospinal at low (possibility 30-59%), head and neck, extremities, cranium and breast at minimal risk (possibility less than 30%). The recommendation for the use of antiemetic in the high risk category is prophylaxis with a 5-HT3 antagonist before each fraction and for at least 24 hours after, with or without dexamethasone added to the 5-HT3 antagonists. For moderate risk level of RIE, patients should receive a prophylaxis with a 5-HT3 receptor antagonist before each fraction for the entire duration of the cycle. Prophylaxis or rescue treatment with a 5-HT3 antagonist is used for low risk level patients, with the rescue being continued prophylactically for each remaining radiation treatment day. Only rescue treatment with a dopamine or a 5-HT3 receptor antagonist is needed for minimal risk patients. “The MASCC Perugia Consensus Conference 2004 represented an important attempt to unify recommendations given by different organizations and develop a valid tool for the prophylaxis and treatment of radiotherapy-induced emesis,” Maranzano et al. concluded.(Source: Radiother Oncol 76(3):227-233 Sep 2005.)