Radiation-induced emesis: A prospective observational multicenter Italian trial

Purpose: A prospective observational multicenter trial was carried out to a ssess the incidence, pattern, and prognostic factors of radiation-induced e mesis (RTE), and evaluate the use of antiemetic drugs in radiation oncology clinical practice. Methods and Materials: Fifty-one Italian radiation oncology centers took pa rt in this trial. The accrual lasted 2 consecutive weeks, only patients sta rting radiotherapy in this period were enrolled. Exclusion criteria were ag e under 18 years, and concomitant chemotherapy. Evaluation was based on dia ry cards filled in daily by patients during radiotherapy and I week after s topping it. Diary cards recorded the intensity of nausea and any episode of vomiting and retching. Prophylactic and symptomatic antiemetic drug prescr iptions were also registered. Results: Nine hundred thirty-four patients entered the trial, and 914 were evaluable. Irradiated sites were: breast in 211 patients, pelvis in 210 pat ients, head and neck in 136 patients, thorax in 129 patients, brain in 52 p atients, upper abdomen in 42 patients, skin and/or extremities in 37 patien ts, and other sites in 97 patients. Vomiting and nausea occurred in 17.1% a nd 37.3% of patients, respectively, and 38.7% patients had both vomiting an d nausea. At multifactorial analysis, the only patient-related risk factor that was statistically significant was represented by previous experience w ith cancer chemotherapy. Moreover, two radiotherapy (RT)-related factors we re significant risk factors for RIE, the irradiated site and field size. In fact, a statistically significant higher percentage of RIE was registered in upper abdomen RT and RT fields > 400 cm(2). Although nonstatistically si gnificant, patients receiving RT to the thorax and head and neck presented a higher incidence of RIE. Only a minority (14%) of patients receiving RT w ere given an antiemetic drug, and the prescriptions were more often symptom atic than prophylactic (9% vs. 5%, respectively). Different compounds and a wide range of doses and schedules were used; however, there is some eviden ce from our data that in spite of antiemetic prophylaxis, 46% of patients h ad vomiting, and 58% had nausea. The majority (93%) of the prophylactic gro up received oral 5-hydroxytriptamine receptor (5-HT3) antagonist (8 mg/day, 7 days/week). In the symptomatic group, 54% and 41% patients received 5-HT 3 antagonists and metoclopramide, respectively. At multivariate analysis, n o patient- or PT-related risk factor for RIE was found to influence signifi cantly the prophylactic or symptomatic use of antiemetics. Conclusion: Our study provided useful data on epidemiology and characterist ics of RIE. Previous chemotherapy, field size, and irradiated site (upper a bdomen) were the only significant prognostic factors of RIE. A remarkable i ncidence of RIE was found in patients submitted to thoracic and head and ne ck RT. With this background of knowledge, it will be possible to better pla n further studies on this important problem. Moreover, the low rate of anti emetics use and the wide variety of doses and schedules employed suggest th e need to reinforce the "evidence based" approach to identify the best anti emetic approach to RIE. (C) 1999 Elsevier Science Inc.