**2. Epidemiology**

CINV involves about 60–80% of patients with cancer increasing the risk of patients' discomfort and chemotherapy's discontinuation [1]. The prevention of CINV is mainly important in reducing morbidity and total healthcare costs, as well as increasing the quality of care in patients receiving emetogenic chemotherapy. Patients experiencing CINV may refuse treatment, request or require dose reductions or seek alternative therapy options. Acute CINV may be prevented in 50% to 90% of patients using effective preventive strategies [2]. In a large European observational study, 1000 patients who had received guideline antiemetic treatment had significantly better CINV control than those who did not receive guideline treatment. The complete control rates were 60% versus 51%, respectively; however, the overall adherence to guidelines was just 29% [3].

Radiotherapy-induced nausea and vomiting (RINV) is one of the most common side effects during radiation, from which about 50% to 80% of the patients undergoing radiotherapy will suffer [4].
