Comparative diagnostic values of grey-scale USS versus CT scan in the primary management of gynaecological pelvic mass with emphasis on ovarian cancer detection and staging

Abstract

Thirty-one consecutive patients with clinical pelvic masses suspected to be gynaecological in origin were initially investigated by transabdominal grey-scale ultrasound (TAUS) and then by computed tomography (CT) prior to surgery and or chemotherapy. Retrospective comparative review of the reports of the two imaging methods was carried out on each patient and then correlated with surgical findings and histopathology report. The diagnostic potentials of the two imaging methods with respect to ovarian cancer detection and staging were particularly emphasised. The results were analysed and compared with published results of similar studies in the literature. Compared with TAUS we found CT scan more sensitive in making an overall presumptive diagnosis of pelvic mass (15/31, 48% vs. 9/31, 29%). The sensitivity of CT scan for all ovarian cancer detection was greater than that of TAUS (5/6, 83% vs. 4/6, 67%) but TAUS was more specific. The false negative and false positive values for cancer detection were comparable. Both methods were equally efficacious in detecting and staging advanced ovarian cancer cases (4/4, 100%). Visualisation of the ovaries occurred more readily with TAUS, which in addition offered a more precise assessment of ovarian tumour size. There were no significant differences in the two methods regarding tumour localisation (organ of origin), characterisation and the details of descriptive report when no presumptive diagnosis is offered. Overall CT did not offer significant additional features and did not result in changes in management plan in any of the patients reviewed. The marginal benefit of CT scan over TAUS will not warrant its routine usage in the diagnosis of gynaecological pelvic mass. Our findings largely reflected the conclusions of published reports in the literature.