A comparison of intratumoural indices of blood flow velocity and impedance for the diagnosis of ovarian cancer

Abstract

The aim was to assess the value of blood flow velocity indices in an ultrasound-based test to discriminate between malignant and benign adnexal tumours. Fifty-one women (35 premenopausal and 16 postmenopausal) with persistent adnexal masses were scanned prior to surgery using transvaginal sonography with colour Doppler imaging. Intratumoural flow velocity waveforms obtained by pulsed Doppler sonography were used to determine the time averaged maximum velocity (TAMXV), peak systolic velocity (PSV), pulsatility index (PI) and resistance index (RI). The tumours were classified by histologic criteria (42 benign, 1 borderline and 8 malignant tumours). Two of the malignant and the single borderline tumour were stage I, five were stage III and one was stage IV. Detectable blood flow signals were found in all malignant and borderline tumours and in 33 of 42 (78.6%) of the benign tumours. TAMXV was the best parameter for discrimination of benign and malignant adnexal pathology and at a cut-off value of TAMXV ≥12 cm/s to indicate malignancy, the sensitivity and specificity were 88.9% and 81.0%, respectively. At the same sensitivity level, this gave a better specificity than the PI ≤0.90 (specificity 61.9%, P = 0.036), RI ≤ 0.60 (specificity 54.8%, P = 0.010) and PSV ≥ 16 cm/s (specificity 71.4%, P = 0.121). Discrimination between benign and malignant tumours was improved further by using two criteria rather than one. When the two criteria of a TAMXV of ≥12 cm/s and a PI ≤ 1.0 were applied simultaneously, the tumours could be characterised with a sensitivity of 88.9% and a specificity of 88.1%. Therefore, intratumoural PSV and TAMXV could be used to discriminate between benign and malignant adnexal tumours better than values for PI and RI. The best discrimination was achieved by using a combination of cut-off values for velocity and impedance parameters as two criteria to define malignancy.