Hematology, Transfusion and Cell Therapy (Apr 2024)
COMPARISON OF 68GA-PSMA AND 18F-FDG-PET/CT IN THE ASSESSMENT OF DESMOID TUMORS
Abstract
Introduction/Justification: Recently, the tracer Prostate Specific Membrane Antigen (PSMA), which can be labeled with the radioisotopes 68Ga or 18F, has been commercially introduced. Theoretically, as the name suggests, it is a substance specific to the membrane of prostate cells and prostate cancer. However, several studies have shown that it is also a marker of neoangiogenesis, leading to its uptake in various other neoplasms and benign diseases. Objectives: This study aims to evaluate the utility of radiolabeled PSMA in detecting desmoid tumors, comparing it to 18F-luorodeoxyglucose (FDG). Materials and Methods: Three participants with a confirmed diagnosis of desmoid tumor underwent PET/CT examinations with 18F-PSMA and 18F-FDG, with a maximum interval of 3 days between examinations. Images were visually compared lesion by lesion and the maximum standardized uptake value (SUV) was calculated for each lesion and each radiopharmaceutical. Results: All lesions presented uptake of both 68Ga-PSMA and 18F-FDG. In the first patient, 3 lesions were identified: a mass adjacent to the pancreas measuring 5.4 cm (FDG: SUV = 2.0) (PSMA: SUV = 8.2), a mass in the right iliac fossa measuring 7.7 cm (FDG: SUV = 3.8) (PSMA: SUV = 5.7), and another involving the duodenojejunal transition measuring 4.1 cm (FDG: SUV = 1.9) (PSMA: SUV = 3.7). In the second patient, a mass was identified adjacent to the head and uncinate process of the pancreas measuring 9.2 cm (FDG: SUV = 9.8) (PSMA: SUV = 6.1). In the third patient, an irregular retroperitoneal mass was identified at the level of the aortic bifurcation (FDG: SUV = 2.3) (PSMA: SUV = 2.4). Conclusion: Desmoid tumors can demonstrate uptake of both 68Ga-PSMA and 18F-FDG. The intensity of tracer uptake in the lesions is variable, with some showing greater uptake of FDG, others of PSMA, suggesting a potential complementary role for these radiotracers in desmoid tumors.