Clinically oriented three-step strategy to the assessment of adnexal pathology.

Objective If we exclude masses likely to be judged as easy and "instant" to diagnose by an ultrasound examiner, what is the diagnostic performance of ultrasound based simple rules, RMI, two logistic regression models and real-time subjective assessment by experienced ultrasound examiners? Patients and methods 3511 patients with at least one persistent adnexal mass preoperatively underwent transvaginal ultrasonography to assess tumor morphology and vascularity. They were included in two consecutive prospective studies by the International Ovarian Tumor Analysis (IOTA) group: phase 1 (1999-2005) development of the simple rules and logistic regression models LR1 and LR2, and phase 2 a validation study (2005-2007). Results Almost half of the cases (43%) were identified as "instant" to diagnose on the basis of descriptors applied to the database. To assess the performance in the more difficult "non-instant" masses, we used only phase 2 data (N = 1036). The sensitivity of LR2 was 88%, RMI 41% and subjective assessment 87%. The specificity of LR2 was 67%, RMI 90% and subjective assessment 86%. The simple rules yielded a conclusive result in almost 2/3 of the masses where they resulted in sensitivity and specificity similar to real-time subjective assessment by experienced ultrasound examiners: sensitivity 89% vs. 89% (P-value 0.76), specificity 91% vs. 91% (P-value 0.65). If we apply a three-step strategy with easy "instant" diagnoses as step 1, simple rules as step 2 and subjective assessment by an experienced ultrasound examiner in the remaining masses as step 3 we obtain a sensitivity of 92% and specificity of 92% compared to sensitivity 90% (P = 0.03) and specificity 93% (P = 0.44) when using real-time subjective assessment by experts in all tumors, respectively. Conclusion A diagnostic strategy using simple descriptors and ultrasound rules when applied to the variables contained in the IOTA database obtains results that are at least as good as those obtained by subjective assessment of a mass by an expert.