Postoperative radiotherapy for head and neck squamous cell carcinomas: feasibility of a biphasic accelerated treatment schedule.

Abstract

It has been suggested that postoperative tumor cell proliferation may influence the outcome of advanced head and neck squamous cell carcinomas treated by surgery and postoperative radiotherapy. This Phase I pilot study was undertaken to determine the feasibility of a biphasic accelerated radiotherapy regimen with early and late concomitant boost delivery for postoperative treatment of patients with advanced head and neck cancers. From April 1993 to April 1994, 29 patients with advanced head and neck cancers were enrolled in this study after they underwent complete surgical resection. The basic radiation course delivered a median dose of 49 Gy in 25 fractions over 5 weeks at 1.8-2 Gy/fraction. The concomitant boost was delivered to the high-risk areas as a second daily fraction during the first (1.4 Gy/fraction) and fifth weeks (1.6 Gy/fraction). The total dose to the high-risk areas was 64 Gy in 35 fractions over 5 weeks. Twenty-seven patients (93%) completed the treatment without interruptions. Only two patients experienced severe acute toxicity requiring treatment breaks of 6 and 8 days, respectively. All patients developed confluent mucositis; in 69% of the cases it covered >50% of the treated surface. No patient developed Grade 5 (ulceration/bleeding) mucosal reaction. Mucositis required a median time of 7 weeks for complete healing (range 3-43). Two patients developed transient bone exposure. The median weight loss was 5.5% of pretreatment body weight (range 1.2-17.1%), and four patients required nutritional assistance with nasogastric feeding tube. The results of this study show that this biphasic acceleration regimen is feasible with acceptable acute toxicity.