[68Ga]Ga-Prostate-specific membrane antigen PET/CT in ovarian tumours: potential to differentiate benign and malignant tumours before surgery. A preliminary report

Abstract

Purpose 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 tumours such as ovarian cancer. The aim of this pilot study was to evaluate the feasibility of using [ 68 Ga]Ga-PSMA-11 PET/CT in detection of ovarian neoplasm before surgical treatment. Material and methods: 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 min after injection of 2 MBq/kg [ 68 Ga]Ga-PSMA-11. Results: In three cases (37.5%) the [ 68 Ga]Ga-PSMA-11 PET/CT was positive, whereas histological examination confirmed two serous ovarian cancer cases and one ovarian borderline tumour. The SUVmax in the serous ovarian cancer was 8.7 and 4.1, and in the borderline ovarian tumour it was 13.8. No correlation was found between antigen CA 125 level and [ 68 Ga]Ga-PSMA expression. Range of tumour SUVmax was not correlated with stage of disease. The remaining 62.5% (5/8) were negative in [ 68 Ga]Ga-PSMA-11 PET/CT and histopathology confirmed benign pelvic tumour. Conclusion The initial experience supports the potential to use [ 68 Ga]Ga-PSMA-11 in ovarian cancer to differentiate malignant and benign tumours before surgery. This study was approved by the Ethical Committee of the Medical University of Warsaw (KB/2/A/2018).