Prophylaxis of radiation-induced nausea and vomiting: a systematic review and meta-analysis of randomized controlled trials

Background: The aim of this article was to systematically review the efficacy and safety of various antiemetics in prophylaxis of radiation-induced nausea and vomiting (RINV). Methods: A literature search of Ovid MEDLINE, EMBASE and Cochrane CENTRAL was performed to identify randomized controlled trials (RCTs) that evaluated the efficacy of prophylaxis for RINV in patients receiving radiotherapy to abdomen/pelvis, including total body irradiation (TBI). Primary endpoints were complete control of nausea and complete control of vomiting during acute and delayed phases. Secondary endpoints included use of rescue medication, quality of life (QoL) and incidence of adverse events. Results: Seventeen RCTs were identified. Among patients receiving radiotherapy to abdomen/pelvis, our meta-analysis showed that prophylaxis with a 5-hydroxytryptamine-3 receptor antagonist (5HT3 RA) was significantly more efficacious than placebo and dopamine receptor antagonists in both complete control of vomiting [OR 0.49; 95% confidence interval (CI): 0.33-0.72 and OR 0.17; 95% CI: 0.05-0.58 respectively] and complete control of nausea (OR 0.43; 95% CI: 0.26-0.70 and OR 0.46; 95% CI: 0.24-0.88 respectively). 5HT3 RAs were also more efficacious than rescue therapy and dopamine receptor antagonists plus dexamethasone. The addition of dexamethasone to 5HT3 RA compared to 5HT3 RA alone provides a modest improvement in prophylaxis of RINV. Among patients receiving TBI, 5HT3 RA was more effective than other agents (placebo, combination of metoclopramide, dexamethasone and lorazepam). Conclusions: 5HT3 RAs are more effective than other antiemetics for prophylaxis of RINV in patients receiving radiotherapy to abdomen/pelvis and TBI. Future RCTs should investigate the efficacy of newer agents such as substance P neurokinin 1 receptor antagonists in addition to 5HT3 RAs in prophylaxis of RINV during both acute and delayed phases.