Journal Article

A pilot study of PSMA-targeted F-18-DCFPyL PET imaging of patients with adenoid cystic carcinoma

Shen, Colette J., Bishop, Justin A., Wang, Jarey, Kiess, Ana P., Voter, Andrew F., Pomper, Martin G., Solnes, Lilja B., Kang, Hyunseok, Rowe, Steven P., Amindarolzarbi, Alireza, Sharma, Rajni

2025

Overview

Adenoid cystic carcinoma (ACC) is a rare malignancy of the salivary glands with poor long-term outcomes and with a need for improved imaging and therapeutic options. Prostate-specific membrane antigen (PSMA) expression has been observed in ACC and preliminary studies have demonstrated PET imaging using 68 Ga-functionalized PSMA agents for positron emission tomography (PET). We aimed to assess the extent of PSMA expression in a collection of archival ACC samples and demonstrate the feasibility of using  18 F-DCFPyL for PSMA PET imaging of ACC. PSMA expression levels were assessed in 77 ACC and 11 unaffected parotid gland control samples by immunohistochemistry and quantified by mean H-score. Three patients with metastatic ACC, who had previously undergone local resection, were imaged with 18 F-DCFPyL PSMA PET in a prospective, pilot trial setting. Demographic, oncologic, and treatment history from the PET patient cohort were acquired at the time of imaging. Maximum standardized uptake values (SUV max ) were obtained from representative presumptive metastatic lesions on the  18 F-DCFPyL scans by manual placement of regions-of-interest. PSMA expression was detected in 52% of archival ACC samples, compared to 18% in the unaffected salivary glands. Moderate or high levels of PSMA expression (H-score > 5) were seen in 37% of samples. Radiotracer avid disease was identified on PET imaging of all three patients with tumor SUV max values of 4.1, 4.0, and 2.0, corresponding to tumor-to-liver ratios of 0.7, 1.0, and 0.4 respectively. We find that PSMA is expressed in a majority of histologic samples from patients with ACC. We also demonstrated the feasibility of  18 F-DCFPyL PSMA-targeted PET imaging in the assessment of ACC. Overall, the tumor uptake on  18 F-DCFPyL PET was modest compared to lesional uptake seen in prostate cancer. Given the potential role of PSMA-targeted agents in the management of ACC, broadening access to PSMA PET through F-18-labeled PSMA PET agents is important. Clinical trials investigating the use of PSMA-targeted radioligand therapies for ACC are underway.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 692/308/575 / 692/4028/67/1536 / 692/4028/67/2321 / Adenoid / Adenoid cystic carcinoma / Adult / Aged / Antigens, Surface - metabolism / Cancer / Carcinoma / Carcinoma, Adenoid Cystic - diagnostic imaging / Carcinoma, Adenoid Cystic - metabolism / Carcinoma, Adenoid Cystic - pathology / Clinical trials / Drug dosages / Exocrine glands / FDA approval / Female / Fluorine Radioisotopes / Glutamate Carboxypeptidase II - metabolism / Humanities and Social Sciences / Humans / Immunohistochemistry / Liver / Lymphatic system / Lysine - analogs & derivatives / Male / Malignancy / Medical prognosis / Metastases / Metastasis / Middle Aged / multidisciplinary / Parotid gland / Patients / Pilot Projects / Positron emission tomography / Positron emission tomography (PET) / Positron-Emission Tomography - methods / Prospective Studies / Prostate / Prostate cancer / Prostate-specific membrane antigen / Radiation / Radioactive tracers / Radiopharmaceuticals / Salivary gland / Salivary Gland Neoplasms - diagnostic imaging / Salivary Gland Neoplasms - metabolism / Salivary Gland Neoplasms - pathology / Science / Science (multidisciplinary) / Tumors / Urea - analogs & derivatives / White people