Preoperative hypoxyradiotherapy of XXXX .

@entity1 @entity137 @entity5 @entity4272 @entity26 @entity519 @entity14 @entity2335
AIM: The article focuses on the radioprotective effect of acute @entity519 on healthy tissues during preoperative accelerated hypoxyradiotherapy of @entity14 performed as locoregional irradiation including the common iliac lymph nodes. Analysis of early and late side effects and complications. @entity1 AND METHODS: In this prospective study, early and late complications were assessed in 50 @entity1 as a function of hypoxyradiotherapeutic dose increase. The preliminary treatment results of this radiotherapeutic modification were evaluated after a median follow-up of 48 months using Kaplen-Meier analysis. Between April 1991 and February 1997, 50 @entity1 (36 @entity1 and 14 @entity1 ) with @entity14 were treated preoperatively with locoregional accelerated hypofractionated hypoxyradiotherapy. The extent of disease was classified according to Dukes' criteria (A: four @entity1 , B. 28 @entity1 , C: 18 @entity1 ). We used a 20-MeV linear accelerator with two parallel opposed fields. Hypoxyradiotherapy was performed extending from the perineum to the L4 region. Acute @entity519 was induced during irradiation by ventilation of a @entity519 gas mixture containing 7.8-8.0% @entity26 . Total doses of 24 Gy/8 days, 28 Gy/9 days, and 32 Gy/10 days were applied in five, 20, and 25 @entity1 , respectively. Low anterior resection or abdominoperineal amputation of the rectum was performed the day after completion of preoperative hypoxyradiotherapy. The early reactions after irradiation were evaluated according to the Common @entity137 Criteria of the National @entity5 Institute (CTC-NCI). RESULTS: Early postirradiation @entity4272 was documented in three and early radiation-induced @entity2335 in two @entity1 only. Neither early nor late radiation-associated complications were observed in any of the three hypoxyradiotherapy schedules during the follow-up period of 6-105 months. Based on Kaplan-Meier analysis (median 48 months), a 5-year overall survival rate of 61.5% and a local relapse-free survival rate of 84.2% can be expected. Treatment failures were predominantly systemic. CONCLUSION: We believe it can be concluded that acute @entity519 has a radioprotective effect on normal tissues during accelerated hypoxyradiotherapy of @entity14 . Hypoxyradiotherapy permits safe administration of doses higher than those tolerated by normoxic, noncanceorus tissue, resulting in the amplification of the biological effect of radiation on @entity5 tissue and contributing to an improved outcome after combined radiosurgical treatment of @entity14 .
