the debate on pelvic lymphadenopathy size significance in ovarian cancer patients

Background: this study attempts to ascertain a reliable cutoff size to determinewhether pelvic lymph nodes are metastatic or not in ovarian cancer patients.methods: we retrospectively reviewed 73 pet/ct scans of 52 female patients withovarian carcinoma who underwent surgery followed by chemotherapy. the findingsof contrast enhanced mdct were interpreted by two experienced radiologists unawareof the pet/ct findings. at least two experienced nuclear medicine physicians unawareof the contrast enhanced-mdct findings examined the pet scans in order to localize,characterize and compare these scans to co-registered pet/ct images. a comparativestudy was done. lymph node sizes were recorded in short axis diameter with asignificant cut off estimated at 7.5 mm. metabolic activities of different lymph nodegroups were assessed and the semi-quantitative suv was calculated. the level of suvsignificance was 2.5. significant metastatic lymph nodes were judged by the assessmentof integrated pet/ct results.results: of the 73 scans, 47 showed significant lymph node metastases, with thefollowing sensitivities: 75% (external iliac), 77.8% (internal iliac), and 75% (inguinal).the specificities were 84% (external iliac), 86% (internal iliac), and 54% (inguinal)with a p-value of 0.000 for the external an internal iliac groups and 0.079 for the inguinalgroup.conclusion: to improve detection of malignant pelvic lymph nodes, the sizethreshold should be decreased to 7.5 mm.