Diffusion-weighted MRI as a Predictor of Outcome in Cervical Cancer Following Chemoradiation
Menée sur 69 patientes atteintes d'un cancer du col de l'utérus traité par chimioradiothérapie définitive (durée médiane de suivi : 16,7 mois), cette étude évalue l'intérêt du coefficient de diffusion apparent d'une IRM pondérée en diffusion pour prédire avant traitement la survie des patientes
Purpose : Diffusion weighted magnetic resonance imaging (DWI MRI) is emerging as a useful diagnostic and prognostic imaging technique in cervical cancer. We aimed to determine if apparent diffusion coefficient (ADC) value is predictive of survival following definitive chemoradiation for cervical cancer independent of established imaging and clinical prognostic factors.
Methods and Materials : Between 2011-2013, the pre-treatment MRIs for 69 patients treated with definitive chemoradiation for newly diagnosed cervical cancer were retrieved. Scans were acquired with a 1.5 T magnetic resonance scanner, including DWI sequences. Mean ADC value was measured within a region of interest in the primary cervical cancer on the baseline MRI. Baseline tumor maximum standardized uptake value (SUV) on the PET/CT was determined by the reading radiologist. Treatment included external beam radiation therapy to the pelvis followed by brachytherapy in 97%, and with concurrent weekly cisplatin in 99% of patients. Univariate and multivariate analyses were done to investigate the association of clinical and imaging variables with disease control and survival endpoints using a Cox proportional hazard test.
Results : Median follow-up was 16.7 months (range 3.1-44.2). The 1-year overall survival, locoregional recurrence-free survival, and disease-free survival (DFS) were 91%, 86% and 74%, respectively. The median ADC value was 0.941 x 10-3 mm2/s (range [0.256-1.508] x 10-3 mm2/s). The median SUV in the primary tumor was 15 (range 6.2-43.4). In multivariate analysis, higher ADC value (HR 0.36 [0.15-0.85], p=0.02), higher stage (HR 2.4 [1.1-5.5], p=0.033), and non-squamous histology (HR 0.23 [0.07-0.82], p=0.024) were independent predictors of DFS.
Conclusion : The mean ADC value of the primary tumor on pre-treatment MRI was the only imaging feature which was an independent predictor of DFS in cervical cancer patients treated with chemoradiation. Further validation will be needed to determine if ADC values may prove useful in identifying cervical patients at high risk of recurrence.
International Journal of Radiation Oncology • Biology • Physics , résumé, 2015