Differential Diagnosis of Borderline Ovarian Tumors from Stage I Malignant Ovarian Tumors using FDG PET/CT

Purpose

Borderline ovarian tumors (BOTs) are more common in young women of reproductive age, and exhibit a better prognosis than malignant ovarian tumors (MOTs). Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) were compared in their ability to differentiate BOTs from stage I MOTs.

Methods

Among 173 patients who had preoperative FDG PET/CT due to ovarian neoplasms between November 2006 and March 2009, there were 13 patients with BOTs or stage I MOTs. For differential diagnosis of the two tumors, cancer antigen-125 (CA-125) level, the longest diameter of tumors, metabolic indices including maximum standardized uptake value (SUV_max), and volumetric indices including metabolic tumor volume (MTV) were compared, respectively.

Results

The BOT group (n = 7) was comprised of five mucinous and two serous tumors, and the MOT group (n = 6) was comprised of three endometrioid, two clear cell and one mucinous tumors. Among the comparisons between two groups, SUV_max of the BOT group was significantly lower than that of the MOT group (2.9 ± 1.5 vs. 6.6 ± 2.9, p = 0.0223); otherwise, no significant difference was found in age, CA-125, diameter, or MTV. By receiver-operating characteristic curve analysis, SUV_max of 3.7 was the best cutoff value to differentiate BOTs from stage I MOTs, with a sensitivity of 83.3 % and specificity of 85.7, and the area under curve of 0.893 (p = 0.0001, 95 % CI: 0.601∼0.993).

Conclusions

We demonstrated that SUV_max could distinguish BOTs from stage I MOTs, with a high sensitivity and specificity. Metabolic indices determined by FDG PET/CT were more suitable than volumetric indices for differential diagnosis of the two tumors.