EP24.05: Prospective study: transvaginal ultrasound for endometriosis, incorporating IDEA consensus and novel superficial endometriosis inclusion

Transvaginal ultrasound (TVS) is crucial for diagnosing endometriosis, guided by the International Deep Endometriosis Analysis (IDEA) guidelines. While TVS excels in diagnosing ovarian (OE) and deep endometriosis (DE), superficial endometriosis (SE) remains elusive. Previous studies relied on outdated classification guidelines, hindering our understanding of TVS diagnostic accuracy. This study aims to pioneer our understanding of TVS accuracy for DE, OE, and SE, using IDEA consensus and updated guidelines. We performed a prospective diagnostic accuracy study at a tertiary endometriosis referral centre. The index test was TVS, reported in accordance with IDEA consensus and laparoscopy as the reference standard, conducted by the same surgeon sonologist. SE and DE were defined according to the novel classification guidelines as the presence or absence of infiltration. Accuracy (Acc), sensitivity (Sens), specificity (Spec), positive and negative predictive values (PPV/NPV) were calculated for each phenotype and site relative to the reference standard. 125 participants were included. Diagnostic performance of TVS in DE: Acc 92.7 - 99.2%, Sens 82.3 - 100%, Spec 97.0 - 100%, PPV 94.1 - 100%, NPV 88.9 - 100%. For OE of the left and right ovary, respectively, was: Acc 98.3% and 98.4%, Sens 95.0% and 94.9%, Spec 100% and 100%, PPV 100% and 100%, NPV 97.6% and 97.7%. SE assessment in the population excluding DE, OE, and POD obliteration showed: Acc 73.9 - 87.0%, Sens 12.5 - 54.9%, Spec 100%, PPV 100%, NPV 72.2 - 84.6%. TVS demonstrates strong diagnostic performance for DE and OE across anatomical sites. While diagnosing SE is challenging, TVS exhibits strong specificity. These findings support TVS as a primary diagnostic for DE and OE, with enhanced accuracy. However, novel diagnostics are needed to confidently rule out SE, reducing diagnostic delay and improving surgical planning.