INTRAOPERATIVE RADIOTHERAPY FOR ESOPHAGEAL-CARCINOMA - SIGNIFICANCE OF IORT DOSE FOR THE INCIDENCE OF FATAL TRACHEAL COMPLICATION

Purpose: The feasibility of intraoperative radiotherapy (IORT) combined with modified regional lymphatic dissection (plus esophagectomy) for advanced esophageal carcinoma was tested. The quality of life in the patients was expected to improve by modified surgery, securing a good local control by additional IORT. Methods and Materials: Total esophagectomy plus modified three-regional lymphatic dissection with upper mediastinal IORT followed by postoperative external beam irradiation was systematically given to 62 patients between August 1989 and June 1992. Sixty-five percent of the patients were age over 60, and 76% (47/62) of the patients were Stage III or IV by pTNM. Several techniques for the IORT were developed and used throughout this period, including a temporary collapse of the right lung by unilateral tracheal intubation (for the insertion of IORT applicator) and an in vivo dosimetry to know the appropriate range (energy) of electron beam. The method of surgical treatment, the dose of external beam irradiation were kept standardized, and only the dose of IORT was randomized either to 20 or 25 Gy. IORT-related complications and the pattern of failures were carefully monitored. Results: (a) Most prominent IORT-related complication was the late tracheal damage, which occurred 6 of 44 patients who were at risk for more than a year. (b) The incidence of IORT-induced tracheal damage was sharply dependent on the dose of IORT; 6 out of 21 patients who received single dose of 25 Gy, and none out of 33 who were given 20 Gy or less. (c) 2-year cause-specific survival and actuarial 2-year survival were 75.0 +/- 14.5% and 62.5 +/- 13.2%, respectively. No loco-regional recurrence has been detected at the time of analysis. Conclusion: IORT in combination with modified total esophagectomy is an effective and safe method to obtain a local control in advanced esophageal carcinomas, if the dose of IORT does not exceed 20 Gy.