Randomized clinical trial on continuous 7-days-a-week postoperative radiotherapy for high-risk squamous cell head-and-neck cancer: a report on acute normal tissue reactions

Abstract

Background and purpose: To analyse acute mucosal reactions in patients treated with continuous accelerated postoperative irradiation (p-CAIR) compared to conventionally fractionated postoperative radiotherapy (p-CF).

Patients and methods: The patients were randomly assigned to receive 63 Gy in 1.8 Gy fractions 7-days-a-week given over a period of 5 weeks (n=88), or 63 Gy in 1.8 Gy fractions given 5-days-a-week over 7 weeks (n=87). It represents 65% of an overall trial size. Acute mucosal reactions were scored using modified Dische system. Polychotomous logistic regression was used to estimate the influence of the selected variables on maximum grade of mucositis, and percent of the body weight loss during radiotherapy.

Results: The average maximum Dische score and percent of the patients with confluent mucositis were higher in patients treated with p-CAIR, compared to p-CF (13.3 vs. 10.8 and 54 vs. 27%). Polychotomous logistic regression analysis revealed that fractionation scheme and tumour site have significantly influenced maximum Dische score. Tumour site (laryngeal vs. other) had even stronger influence on maximum Dische score than fractionation scheme. The average residual Dische score 8 weeks after radiotherapy was higher in p-CAIR compared to p-CF (2.1 vs. 1.4), and was, most frequently, related to persistent mucosal erythema (70 vs. 57% of pts.). No severe consequential toxicity of radiotherapy was observed, so far, in the trial.

Conclusions: While the incidence, intensity and duration of mucosal reactions was higher in p-CAIR than in p-CF the accelerated treatment can be considered tolerable with respect to acute toxicity. In both arms of the trial slight or moderate mucosal erythema was the most frequent acute side effect, which did not completely subside within 8 weeks after irradiation.