Complications following re-irradiation for head and neck cancer

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.

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.

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.

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.