Randomized clinical trial on 7-days-a-week post-operative radiotherapy vs concurrent post-operative radiochemotherapy in locally advanced cancer of the oral cavity/oropharynx: a report on acute normal tissue reactions

Objective: The purpose of the study was to evaluate acute normal tissue reactions and treatment compliance in a randomized clinical trial on 7-days-a-week post-operative radiotherapy (p-CAIR) vs post-operative concurrent radiochemotherapy (p-RTCT) in locally advanced cancer of the oral cavity/oropharynx. The sample analyzed at present represents approximately 30% of the intended future trial size. Methods: The patients were randomly assigned to receive 63 Gy in 1.8-Gy fractions 7 days a week (n = 44) or 63Gy in 1.8-Gy fractions 5 days a week with concurrent cisplatin 80-100 mg per square metre of body surface area on Days 1, 22 and 43 of the course of radiotherapy (n = 40). Acute mucosal reactions were scored using the modified Dische system. Results: 15 (17.9%) patients, including 5 patients in p-CAIR and 10 patients in p-RTCT, did not comply with the assigned radiation treatment, mostly because of rapid tumour progression or deteriorating general performance. In p-RTCT, 22 (55%) patients received less than the intended three courses of chemotherapy mostly owing to haematological toxicity. The average maximum mucosal severity score was 14.2 in p-CAIR compared with 13.4 in p-RTCT; the difference was not statistically significant (p = 0.31). Conclusion: The schedules compared (p-CAIR and p-RTCT) did not differ considerably with respect to acute mucosal reactions. Haematological toxicity in p-RTCT was elevated compared with p-CAIR. Both schedules were considered tolerable with respect to acute toxicity, which justifies further recruitment to the trial. Advances in knowledge: The results show that early mucosal reactions are comparable in both trial arms but haematological toxicity is more pronounced during radiochemotherapy.