OC04.04: Is the introduction of magnetic resonance in the diagnostic workout of adnexal masses just an increase of costs when IOTA Simple Rules are applied?

Is the introduction of magnetic resonance in the diagnostic workout of adnexal masses just an increase of costs when IOTA Simple Rules are applied? S. Guerriero1, A. Piras1, S. Ajossa1, M. Pascual2, I. Rodr´ıguez3, M. Perniciano4, L. Saba4, V. Mais5, J. Alcazar6 1Obstetrics and Gynecology, University of Cagliari, Cagliari, Italy; 2Obstetrics, Gynecology and Reproduction, Institut Universitari Dexeus, Barcelona, Spain; 3Hospital Universitari Quiron Dexeus, Barcelona, Spain; 4University of Cagliari, Cagliari, Italy; 5Surgical Sciences, University of Cagliari, Selargiuos, Cagliari, Italy; 6Obstetrics and Gynecology, University of Navarra, Pamplona, Spain Objectives: The use of magnetic resonance (MR) has been proposed as problem solving in case of indeterminate masses at ultrasound for the detection of ovarian cancer. The aim of the present study was to investigate the costs of a diagnostic workup using MR when International Ovarian Tumors Analysis (IOTA) Simple Rules (SR) are applied. Methods: 208 women with adnexal masses were included (recruited from 2016 to 2017) and submitted to transvaginal US (TVS) scan for the identifications of Simple Rules using IOTA criteria. A cost-benefit analysis will be performed. In the Italian National Health System the cost of a TVS is 43¤ and 278¤ for pelvic MR. Results: Only 13 (6.2%, 95% CI 3.7%-10.4%) masses were indeterminate using SR. The sensitivity of SR was 100% with a specificity of 93.19%. The use of SR associated with examination by an expert just in case of indeterminate masses increased the specificity to 96% with the same sensitivity. Using only the TVS by expert as additional evaluation the overall cost was 559¤ while using MR the cost would have been of 3614¤ with an additional cost of 3055¤. For every 1000 patients screened it will be 62.5 indeterminate masses with an additional expected cost of 14687¤ [95% CI 8695¤-24440¤]. Conclusions: Although the rate of indeterminate cysts is very low using a IOTA standardised ultrasonographic approach, the use of expert when SR are applied showed a good accuracy with a lower cost in comparison with the use of MR in not classifiable masses. The present study is supported by Fondazione di Sardegna and Regione Autonoma della Sardegna.