[Study on clinical application of multiple fractions per day radiation therapy with concomitant boost technique for esophageal cancer].

A continuous multiple fractions per day irradiation (MFD) using twice-a-day (BID) fractionation in the similar form of concomitant boost was devised for the treatment of advanced esophageal cancer. From Oct. 1985 to July 1991 60 patients were entered in this clinical trial and were compared with 64 patients who were treated with conventional once-a-day irradiation (CF) from July 1977 to July 1989 in survival, local control, acute and late effect. The altered fractionation schedule employed continuous concomitant boost technique with reduced field for primary site being irradiated twice-a-day. Daily fraction size were 2 Gy with large field including primary and regional lymphatics and 1.1, 1.15 and 1.2Gy with concomitant boost. Total dose of 62, 63 and 64Gy were administered in 40 fraction for 5 weeks. Acute reaction caused radiation mediastinitis, pneumonitis and esophagitis, but severe injury which interrupted treatment did not occur. Late reaction consisted of 8 radiation induced stricture [RIS] (13.3%), 2 radiation induced pericarditis(3.3%) and 1 bronchial ulcer(1.7%) in MFD. Particularly, RIS in 3.2Gy/2f/day group of MFD developed with higher frequency than in CF and another daily fraction size. Patients treated with CF and MFD experienced 5 year loco-recurrence free survival of 27.3% and 57.2% respectively (P < 0.001), which translated into 5 year cause-specific survival 13.9% and 31.5%, respectively (P < 0.05). Significant advantage in adjusted local-recurrence free survival using multivariable analysis was shown (P < 0.005). Also, a border line advantage in adjusted survival using clinical stage is now appearing in MFD as a consequence of the increased local control rate. There was no significant difference in survival and local-recurrence free survival among each daily dose groups. We concluded that our regimen of MFD using optimal daily dose of 3.15Gy/2f/day with continuous concomitant boost technique resulted in improved local control and survival rate of treatment of esophageal cancer without severe late reaction.