Cancers and Benign Processes on 68Ga PSMA PET-CT Imaging Other than Prostate Cancer

Abstract

Background Imaging plays an important role in the evaluation of prostate cancer patients. In recent years, much attention has been focused on gallium 68 prostate-specific membrane antigen positron emission tomography-computed tomography (68Ga PSMA PET-CT) in prostate cancer patients and has been widely used for staging, restaging, and therapy response for these patients. The aim of this study was to report 68Ga PSMA PET-CT in other cancers and benign processes incidentally detected on 68Ga PSMA PET-CT in patients with prostate cancer. Materials and Methods A total of 600 68Ga PSMA PET-CT scans were performed for initial staging, restaging, detection of suspected recurrence, and therapy response in prostate cancer patients between December 2018 and June 2020. A total of 38 patients with histopathologically proven prostate cancer were included in the current study with other malignancies and benign processes. Mainly histopathology in most of cases and clinical and radiological follow-up in few cases after PET/CT scanning served as the standard of reference. Results A total of 38 patients (age range: 52–85 years; mean age: 68.6) with prostate cancer final histopathology results were included in the study. A total of 51 lesion sites were evaluated in 38 patients. Forty-one lesion regions of these 51 regions were based on histopathological diagnosis, whereas 10 of them were based on clinical follow-up and conventional radiological follow-up as differential criteria. Thirty of 51 lesion regions were evaluated as malignant and 21 were benign lesions. The most common 68Ga PSMA ligand avid malignancy was lung adenocarcinoma (6/38). Conclusions Prostate-specific membrane antigen (PSMA) is a cell surface glycoprotein and mainly expressed in prostate epithelium. 68Ga PSMA PET-CT imaging is very sensitive and specific imaging modality in prostate cancer patients. However, other malignancies and some benign processes may also have 68Ga PSMA ligand avidity and some prostate cancer metastases may imitate other malignancies.

Intense prostate-specific membrane antigen receptor expression in coronary artery pypass graft scar tissue: A potential molecular imaging pitfall

“…7 It also showed superiority in evaluation of hybrid synchronous histopathologies as well as patients with multiple primary neoplasms. [8][9][10] The mechanism behind the uptake and localization of PSMA by cancer cells involves the overexpression of PSMA antigen on their surface, allowing for targeted binding and internalization of PSMAtargeted agents. 11 However, the specificity of PSMA is not absolute.…”

“…PSMA expression has been observed in various non-prostatic malignancies, affecting its diagnostic accuracy. 10 It can also be expressed in benign conditions and can occur in postsurgical and reactive scenarios, potentially compromising the reliability of PSMA-based imaging. 10 These factors highlight the importance of cautious interpretation when relying solely on PSMA-based imaging in clinical decision making.…”

“… 10 It can also be expressed in benign conditions and can occur in postsurgical and reactive scenarios, potentially compromising the reliability of PSMA-based imaging. 10 These factors highlight the importance of cautious interpretation when relying solely on PSMA-based imaging in clinical decision making. In this case report, we present a patient with prostate cancer who exhibited PSMA localization at the sites of coronary artery bypass graft (CABG) stitches, which is an unexpected location for PSMA expression.…”

Current status of PSMA-targeted imaging and therapy

“…Moreover, in numerous normal tissues, for example, endometrial glands, testis, bladder, kidney tubules, pancreas islets, heart, and ganglion cells in the gastrointestinal tract and brain, weak-to-moderate levels of PSMA expression have been detected ( 9 ). Although it is reported that certain benign diseases such as lymphadenitis and malignant diseases such as lung adenocarcinoma may also exhibit PSMA uptake ( 10 ), its remarkable sensitivity and specificity for PCa continue to establish it as a dedicated imaging modality for patients with PCa. Thus, PSMA-positron emission tomography (PET) is still considered to be a rather sensitive and highly specific tool for PCa diagnosis despite its expression by subsets of various types of other tissues ( 9 , 11 , 12 ).…”

A Case Series Depicting PSMA Expression in Nonmalignant Lesions

“…[ 1 ] Physiological expression is also seen in renal tubules, lacrimal and salivary glands, and small intestine. [ 2 ] However, PSMA expression can also be seen in inflammation/infection, nonprostatic neoplastic cells, and nonprostatic tumor-associated neovasculature. [ 3 ] Endothelial and cytoplasmic PSMA expression is attributed to PSMA uptake in many nonprostatic tumor cells.…”