68Ga-Prostate-Specific Membrane Antigen PET/CT in Ovarian Tumors: Potential to Differentiate Benign and Malignant Tumors Before Surgery: A Preliminary Report.

Abstract

Ovarian cancer is usually diagnosed in an advanced stage of disease due to the absence of specific symptoms and a lack of sensitive diagnostic methods. Prostate-specific membrane antigen (PSMA) is expressed on prostate cancer cells but can be found in other tumors such as ovarian cancer.The aim of this pilot study was to evaluate the feasibility of using 68Ga-PSMA-11 PET/CT in detection of ovarian neoplasm before surgical treatment. Eight women with mean age of 56.0 ± 16.2 years were included in the study. All patients underwent transvaginal ultrasound followed by CT scan of the chest and abdomen as qualification for surgery. Within a 1-week interval, PET/CT was performed on a Siemens Biograph scanner, 60 minutes after injection of 2 MBq/kg 68Ga-PSMA-11. In 3 cases (37.5%), the 68Ga-PSMA-11 PET/CT was positive, whereas histological examination confirmed 2 serous ovarian cancer cases and 1 ovarian borderline tumor. The SUVmax in the serous ovarian cancer was 8.7 and 4.1, and in the borderline ovarian tumor, it was 13.8. No correlation was found between antigen CA-125 level and 68Ga-PSMA expression. Range of tumor SUVmax was not correlated with stage of disease. The remaining 62.5% (5/8) were negative in 68Ga-PSMA-11 PET/CT, and histopathology confirmed benign pelvic tumor. The initial experience supports the potential to use 68Ga-PSMA-11 in ovarian cancer to differentiate malignant and benign tumors before surgery.This study was approved by the Ethical Committee of the Medical University of Warsaw (KB/2/A/2018).