486 Multivariate analysis of complications of radiotherapy alone in cervix cancers

From 1970 to 1993, 632 patients with carcinomas of intact uterine cervix were treated with radiotherapy alone. The aim of the study is: (1) to describe all types of late normal tissue damage using French Italian syllabus. (2) to determine by univariate and multivariate analysis the predictive factors of rectal, bladder, colon, small bowel, genitalia and soft tissues severe sequelae (G3G4). Results The distribution of sequelae and complications is: G1 23%, G2 18%, G3 6%, G4 2.5%. The distribution of G3G4 per organ is: Genitalia 6% (no G4), rectum 4% colon 1.5%, bladder 1.2%, soft tissues 1%, small bowel 0.5%. Univariate analysis shows an increased risk of G3G4 rectal complications according to Figo substaging, external radiation dose above 40 Gy (ED), parametrium boost (PB), use of brachytherapy vaginal cylinders applicator (CA), high HWT or mean rectal dose rate. Bladder severe sequelae correlate with increased of Figo, ED, PB, CA, ICRU bladder dose and bladder maximum dose rate. The five main factors influencing the genitalia and soft tissues sequelae are Figo, ED, PB, CA and HWT. In multivariate analysis, CA remains the only predictive factor for G3G4 bladder events (odds ratio OR = 10.8); the mean dose rate increase, CA and Figo are predictive of severe rectal sequelae. Prevention of complications based upon individual changes of treatment planning according to dosimetry parameters led to a sharp decrease in severe complications with time (19% before 1978, 14% between 1978–1983, 6% after 1983). No lethal complications occurred after 1983. Five year specific and disease free survival rates per stage of patients treated during each period are similar.