Late radiation effects to the rectum and bladder in gynecologic cancer patients: the comparison of LENT/SOMA and RTOG/EORTC late-effects scoring systems

Purpose: To test the correlation of LENT/SOMA and RTOG/EORTC late-effect scales for rectum and bladder, 116 cases with gynecologic malignancies that were treated with radiotherapy were assessed with both scales. Methods and Materials: All cases had been treated at least 6 months before the date of assessment with external beam radiotherapy (50-54 Gy to midline) and 1-2 fractions of HDR brachytherapy (2x8.5 Gy to point-A for 32 inoperable cases; 1x9.25 Gy to 5-9 mm from the ovoid surface for 84 postoperative cases). The patients were questioned with both scales, and the correlation between the two scales was analyzed by Spearman's rho (rank correlation) test. Results: There were 64 cases with uterine cervix carcinoma and 52 cases with endometrium carcinoma, The overall (external + brachy) doses to ICRU points were 57.8±3.8 Gy for rectum and 59.3±4.9 Gy for bladder. The statistical analysis of LENT/SOMA and RTOG/EORTC scales revealed a very good correlation for rectum (r=0.81; p<0.01) and a good correlation for bladder (r=0.72; p<0.01). Conclusion: The LENT/SOMA system is a further step on the reporting of late radiation effects. Some modifications will improve its precision, and multicentric randomized studies are needed to test its validity