Abstract
148
Objectives The diagnostic accuracy of apparent diffusion coefficient (ADC) value generated from diffusion weighted image (DWI) for ovarian masses has been still struggling, whereas the diagnostic efficacy of 18F-FDG-PET/CT has not reported yet. The purpose of our study was to evaluate the clinical efficacy of PET/CT for ovarian masses by comparing to DWI with ADC measurement.
Methods Twenty-one patients (mean 59.1 y.o.) with pathologically proven ovarian tumor (18 malignant/borderline malignant; 2 granulosa cell tumors, 4 mucinous tumors, 12 adenocarcinomas and 3 benign; 1 endometrial cyst, 2 thecomas) were collected. All patients underwent both MRI and PET/CT examinations before operation. ROI was set in the solid portion for each ovarian mass and measured both mean ADC value and maximum standardized uptake value (SUVmax) in the same area.
Results All tumors demonstrated heterogeneous hyperintensiy on DWI. Mean ADC value and SUVmax of malignant tumors (1.42±0.5, 7.52±5.4) was significantly higher than benign tumors (1.16±0.3, 3.00±1.7), respectively. Two of 3 benign tumors (2 thecomas) showed lower ADC of 0.92, 0.96 and higher SUVmax of 3.9, 4.1, which might reflect on abundant cellular nature. Four of 18 malignant tumors including mucinous component showed lower SUVmax of 2.05±1.01, influenced by less tumor density.
Conclusions Based on only measuring ADC value or SUVmax for ovarian masses would not be reliable in distinguishing between benign and malignant, because it might reflect on tumor cell density. Combined with the presence of low intensity on T2-weightd image or high intensity on T1-weighted image could be suggestive for benign fibrous tumor and possibility of including hemorrhagic or mucinous component