Response to: Correspondence on "ESGO/ISUOG/IOTA/ESGE Consensus Statement on pre-operative diagnosis of ovarian tumors" by Thomassin-Nagarra et al

We thank Isabelle Thomassin-Nagarra et al for their interest in the ESGO/ISUOG/IOTA/ESGE consensus statement on the pre-operative diagnosis of ovarian tumors. This statement is based on a careful review of the relevant literature and available evidence as well as on structured discussions between experienced radiologists, gynecologists, gynecological oncologists and a patient representative. Therefore, we hope that the statement will prove valuable for clinical practice. We fully agree that our patients are best served when different imaging methods are used appropriately. On the other hand, we disagree with several claims made by Thomassin-Nagarra et al. First, they state that ultrasonographers cannot classify 25% of the adnexal masses. However, we showed that experienced ultrasound examiners cannot classify only 8%.1 Although the IOTA Simple Rules are not applicable in about 25% of cases, the Simple Rules Risk model and the IOTA ADNEX model adequately address all tumors.2 Furthermore, the ACR consensus does not recommend MRI for further evaluation of O-RADS US 3 and 4 category lesions, but it does recommend referral to an ultrasound specialist or MRI.3 The prospective European cohort study on MRI4 is discussed in the consensus statement: “The addition of quantitative dynamic contrast-enhanced MRI to diffusion-weighted imaging and anatomical MRI sequences and the development of a five-point scoring system (O-RADS MRI score) is another modern diagnostic development with promising potential for the differentiation between benign and malignant adnexal masses in cases in which ultrasound is unable to provide a clear diagnosis (ie, indeterminate masses)”. It is however, noteworthy that this study did not compare the performance of experienced ultrasound examiners with MRI and that the selection criteria for MRI were not clearly explained. Further studies on the complementary role and clinical impact on decision-making of MRI and ultrasonography are needed with larger sample populations. Finally, Figure 2 in our consensus statement correctly describes ultrasonography as the first step, because it is widely available, not expensive, has no contraindications, is accessible for patients with claustrophobia, does not need intravenous contrast agents, and there is a wealth of evidence of its performance to characterize ovarian tumors. When patients are referred for MRI a clear choice has to be made between pelvic MRI–diffusion-weighted imaging for characterization of adnexal lesions, and whole-body MRI for pre-operative ovarian cancer staging. When there are incidental findings of ovarian masses at MRI, the MRI investigation has not usually been part of the protocol as a pelvic MRI scan for adnexal lesion characterization but as MRI for other clinical reasons, such as sacroiliac joint assessment, lumbar disc protrusion, etc. The ongoing IOTA MRI study (ClinicalTrials.gov NCT02836275) is open to both radiologists and gynecologists and aims to compare the performance of ultrasonography and MRI and to validate the optimal use of different imaging modalities.