PO-1021: A practical MRI based reconstruction method for the new endocavitary and interstitial gynecological template
Radiotherapy and Oncology
157 pts (median age 64 years -range 39-84) were enrolled. All pts underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy with or without pelvic lymphadenectomy; patological stage (FIGO 2008) was I in 150 pts and II in 7 pts. Tumour grading was G1 in 49 pts, G2 in 98 and G3 in 10. All pts underwent high-dose-rate vaginal brachytherapy (total dose 21 Gy in three week-fractions), delivered with vaginal cylinder, with the reference isodose covering the proximal ½ of the vagina.
... l ½ of the vagina. The dose was specified at 5 mm distance from the cylinder surface. The Kaplan-Meier method estimated the probability of locoregional relapse free survival (LRFS), distant metastases-free survival (DMFS) and cancer-specific survival (CSS). Univariate analysis investigated the effect of age, grading, number of excised nodes and pathological stage on loco-regional relapse (LRR), metastases, and tumour-related death. Risk factors in univariate analysis were included in proportional hazard multivariate models. Vaginal toxicity was evaluated with the RTOG/EORTC scale and was correlated with the cylinder diameter (2.5, 3 or 3.5 cm). Results: LRFS occurred in 9/157 (5.8%) pts. Three pts (1.9%) developed liver metastases. At median follow-up of 83 months 144 pts (91.8%) are alive and disease free, 2 pts (1.2%) are alive with disease, 7 pts (4.5%) died from disease and 4 pts (2.5%) died from other causes. The 3-year probability of LRFS, DMFS and CSS was 94.5% (95%CI:89.4-97.2), 98.7% (95% CI: 94.9-99.7) and 96,5% (95% CI: 91.8-98.5) respectively. Median survival was nor reached for any endpoints. At univariate analysis, risk factors for LRR were stage pII (HR: 3.638; 95% CI:1.3-9.8; p=0.011) and less than 12 excised nodes (HR: 7.057; 95% CI:1.6-29.5; p=0.008), while Stage pII was risk factor for metastasis (HR: 22.7; 95%CI:2.392-215.4; p=0.007) and tumour-related death (HR: 4.043; 95% CI: 1.2-13.2; p=0.021). In multivariate Coxregression analysis, stage pII and less than 12 nodes sampled were significantly associated with LRR (HR: 3.88; 95%CI:1.390-10.878; p=0.010 and HR: 6.952; 95%CI: 1.591-30.385; p=0.010), whereas only stage pII was associated with metastasis (HR: 23.1; 95%CI: 2.296-231.485; p=0.008) and tumour-related death (HR: 4.324; 95% CI: 1.223-15.290; p=0.023). Treatment was well tolerated. No pts developed acute or late grade III-IV toxicity. No correlation between the diameter of the applicator and the onset of acute (p=0.512) and chronic (p=0.433) toxicity was observed . Conclusions: Post-operative VBT in pts with early stage endometrial cancer is effective in ensuring vaginal control, with fewer toxic effects. PO-1021 A practical MRI based reconstruction method for the new endocavitary and interstitial gynecological template