Intracavitary brachytherapy combined with external-beam irradiation for squamous cell carcinoma of the thoracic esophagus.

During the 15 year period from 1974 to 1988, 277 patients with previously untreated, histologically confirmed, squamous cell carcinoma of the thoracic esophagus were treated with the Time Dose and Fractionation (TDF) factor of more than 99. Of these, 161 patients were treated with external beam irradiation combined with intracavitary brachytherapy. Intracavitary brachytherapy was done for all patients for whom insertion of an outer applicator 1 cm in diameter was possible and for whom a relatively good performance status was seen at completion of external beam irradiation. Except for mild radiation-induced esophagitis, no acute radiation injuries were noted. The early clinical effect of radiation upon the esophageal lesion was determined by esophagography and esophagoscopy, approximately 1 month after the combined radiotherapy; a complete response was observed in 86 (53.4%) of the 161 patients. Furthermore, after a 5 year follow-up, local control of esophageal cancer was found to have been successful in 51 (31.7%) of the 161 patients. The highest rate of local control was associated with the following criteria: Stage I, T1, tumor length less than 5 cm, and superficial or tumorous type of tumor. The 5-year actuarial survival rates were 43.3% for Stage I, 21.1% for Stage II, and 0% for both Stages III and IV. Benign radiation-induced esophageal ulcerations or strictures did develop in five of the long-term survivors, suggesting that the dosage is close to the maximal tolerance of the esophagus. We recommend that 1500-2000 cGy in two or three fractions is the optimal dosage for intracavitary radiation of the esophageal mucosa after external irradiation of 5500 cGy in 22 fractions for 5.5 weeks or 6000 cGy in 30 fractions for 6 weeks. We believe that intracavitary treatment of esophageal carcinoma is a highly effective and a safe therapeutic modality, not only as a palliative therapy, but also as a radical treatment for patients in Stages I and II.