68Ga-Prostate-Specific Membrane Antigen PET/CT in Endometrial Cancer: A Preliminary Report

Endometrial cancer is the most common gynecological cancer. Prostate-specific membrane antigen (PSMA) is expressed in prostate cancer cells but can be found in other cancers, such as endometrial cancer, during angiogenesis.The aim of this prospective pilot study was to evaluate the feasibility of using 68Ga-PSMA-11 PET/CT in endometrial cancer patients before surgical treatment.

Seven women with a mean age of 58 ± 7.9 years were included in the study. All patients underwent standard imaging studies involving transvaginal ultrasound, ceCT scans of the chest and abdomen, and MRI as qualified for surgery. Additionally, PET/CT was performed on a Siemens Biograph scanner 60 minutes after the injection of 2 MBq/kg 68Ga-PSMA-11.

Six of 7 patients had positive 68Ga-PSMA-11 PET/CT images, and histopathology confirmed endometrial cancer. One patient also exhibited uptake in the left ovary, and final histopathology revealed a hemorrhagic cyst. Lymph node involvement was further confirmed after ceCT fusion with 68Ga-PSMA-11. The consensus of histopathological staging of endometrial cancer and ceCT was 4/7, that of MR was 6/7, and that of 68Ga-PSMA-11 PET/CT was 5/7. All methods were consistent in terms of staging in 3/7 patients.

The initial experience showed the possibility of using 68Ga-PSMA-11 in endometrial cancer patients. However, prospective large studies are needed to explore the real diagnostic role of radiolabelled PSMA in this field.This study was approved by the Ethical Committee of the Medical University of Warsaw (KB/2/A/2018).