Complications following re-irradiation for head and neck cancer.

Purpose: Re-irradiation may induce serious complications because of overdosage to previously irradiated areas. A few reports do exist that describe the incidence and factors related to late complications. In the present study we analyze complications following re-irradiation for head and neck cancers.

Materials And Methods: Between 1984 and 1998, 91 patients presenting with squamous cell carcinoma of the head and neck were re-irradiated with a total dose of 80-144 Gy and overlap fields of 4-128 cm(2). Re-irradiation was administered exclusively with external beam irradiation with conventional (n = 47), hyper- (n = 10), or hypofractionation (n = 34). Chemotherapy was combined with the initial course of irradiation (n = 34) or re-irradiation (n = 18). Follow-up time ranged from 3 to 84 months.

Results: Severe acute reactions occurred in 6.6% of patients. Moreover, incidence was significantly higher (40%) in elderly patients older than 80 years. Severe late complications developed 3-10 months after re-irradiation. The incidence was 13% in 78 patients followed for more than 3 months and 21% in 42 patients with tumor-free status. The complications were observed in 19% of patients previously receiving locoregional irradiation, compared with those receiving local irradiation alone (0%), and in 20% of patients undergoing re-irradiation to the neck, compared with those receiving re-irradiation to the head (3%). These factors were all significant by multivariate analysis. Radiation dose, fractionation method, and overlap area were not significant.

Conclusion: Care should be exercised with respect to the potential for acute complications in elderly patients and late complications in those patients having previously received locoregional irradiation and re-irradiation to the neck.