ARRS 2022 Abstracts

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E2009. Pearls and Pitfalls of Fluorine-18 (F18) Piflufolastat Positron Emission Tomography–Computed Tomography PET-CT Imaging in Prostate Cancer
Authors
  1. Suzan Parhizgar; VA Greater Los Angeles Healthcare System
  2. Gholam Berenji; VA Greater Los Angeles Healthcare System
Background
Piflufolastat fluorine-18 (F18)-targeted PET imaging in the detection prostate cancer recently received FDA approval. Piflufolastat F18 PET-CT has good sensitivity and specificity for the diagnosis of prostate cancer when compared to CT and MRI. For accurate prostate cancer diagnosis, there is a need for understanding the pearls and pitfalls of the imaging with piflufolastat F18.

Educational Goals / Teaching Points
This presentation will show the normal appearance of piflufolastat F18 scans, pitfalls that might be present on piflufolastat F18 scans, and pearls to assist the radiologist to accurately read piflufolastat F18 scans. Piflufolastat F18 is useful in preoperative diagnosis, biochemical recurrence, and metastasis, which might lead to changes in management. This educational exhibit hopefully will lead to a more accurate read of the piflufolastat F18 scans and avoid unnecessary management changes in patients with prostate cancer.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Piflufolastat F18 is a highly selective, small-molecule prostate-specific membrane antigen-targeted PET radiotracer. The physiological distribution of piflufolastat F18 ligands includes normal uptake in the lacrimal glands, salivary glands, bowel, liver, spleen, kidneys, and parasympathetic ganglia, and bone marrow. Intense piflufolastat F18 uptake is present in the lacrimal, parotid, and submandibular glands, small intestine, kidneys, liver, spleen, and bladder. Mild to moderate uptake may be observed in nasal and esophageal mucosa, vocal cords, gallbladder, biliary tract, tracheal and proximal bronchi, mediastinal, axillary, and inguinal lymph nodes, gynecomastia, and sympathetic ganglia such as stellate, celiac, hypogastric, and presacral. High activity of piflufolastat F18 in the urinary bladder and ureters are seen after injection. Activity of piflufolastat F18 in the liver shows no significant change over time and with the increase in piflufolastat F18 uptake in suspected malignant lesions, resulting in better tumor-to-background ratios. Piflufolastat F18 uptake is high in bone with sclerotic lesion of metastases. Bone degenerative changes, benign bone lesions, and rib fractures may demonstrate high piflufolastat F18 uptakes. There is no high uptake of piflufolastat F18 in bones with dedifferentiated metastases in contrast to having a high uptake of 18F-sodium fluoride.

Conclusion
Since piflufolastat F18 is a novel tracer, few publications address the common pitfalls that radiologists encounter when reading piflufolastat F18 scans. The purpose of this educational exhibit is to showcase the normal piflufolastat F18 uptake scans and normal variants as well as pearls and pitfalls. This showcase will hopefully enable the radiologist to a more accurate reads of piflufolastat F18 and assist the clinician to avoid unnecessary management in patients with prostate cancer.