Aprepitant and Granisetron for the Prophylaxis of Radiotherapy-Induced Nausea and Vomiting after Moderately Emetogenic Radiotherapy for Bone Metastases: A Prospective Pilot Study

Purpose: We evaluated the novel combination of aprepitant and granisetron for the prophylaxis of radiotherapy-induced nausea and vomiting (RINV) among patients receiving moderately-emetogenic radiotherapy for thoracolumbar bone metastases. Methods: In this single-centre two-arm nonrandomized prospective pilot study, patients undergoing single-fraction radiotherapy (8 Gy) received aprepitant 125 mg and granisetron 2 mg on the day of radiotherapy and aprepitant 80 mg on each of the first 2 days after the day of radiotherapy. Patients undergoing multiple-fraction radiotherapy (20 Gy in 5 fractions) received aprepitant 125 mg on day 1 of radiotherapy, aprepitant 80 mg on days 3 and 5 of radiotherapy, and granisetron 2 mg on every day of radiotherapy. Symptoms and total medication intake were recorded daily during the acute phase (day 1 of radiotherapy until the first day after the last day of radiotherapy), and the delayed phase (days 2–10 after the last day of radiotherapy). Control of vomiting, retching, and nausea was defined as no symptoms and no use of rescue medication. Results: Control rates for single-fraction patients (n = 13) were 100% for acute nausea, 62% for delayed nausea, 100% for acute vomiting and retching, and 85% for delayed vomiting and retching. Control rates for multiple-fraction patients (n = 6) were 67% for acute nausea, 83% for delayed nausea, 67% for acute vomiting and retching, and 83% for delayed vomiting and retching. No grade 3 or 4 toxicities attributable to the study intervention were observed. Conclusions: The combination of aprepitant and granisetron was safe and efficacious for the prophylaxis of RINV after both single- and multiple-fraction moderately emetogenic radiotherapy for thoracolumbar bone metastases. Our results require confirmation in a larger population.