Prostate-specific membrane antigen PET imaging and immunohistochemistry in adenoid cystic carcinoma-a preliminary analysis.

Adenoid cystic carcinoma (AdCC) of the head and neck is an uncommon malignant epithelial tumour of the secretory glands. Many patients develop slowly growing local recurrence and/or distant metastasis, for which treatment options are limited. A retrospective analysis of 9 AdCC patients was conducted to analyse the visualization of AdCC on PSMA PET/CT and to investigate the expression of PSMA on primary, recurrent and metastatic AdCC tumour tissue using immunohistochemistry.

Local recurrence occurred in six patients and eight developed distant metastasis. All PET/CTs depicted PSMA-ligand uptake. Four PSMA PET/CTs showed suspected residual disease, eight scans depicted uptake in areas suspected of distant metastasis. Median Maximum Standardized Uptake Value (SUVmax) in local recurrent and distant metastatic AdCC was 2.52 (IQR 2.41-5.95) and 4.01 (IQR 2.66-8.71), respectively. All primary tumours showed PSMA expression on immunohistochemistry (5-90% expression), as well as all available specimens of local recurrence and distant metastases.

PSMA PET/CT is able to detect and visualize local recurrent and distant metastatic AdCC. PSMA-specific targeting is supported by PSMA expression on immunohistochemistry.

European journal of nuclear medicine and molecular imaging. 2017 Jun 07 [Epub ahead of print]

Thomas J W Klein Nulent, Robert J J van Es, Gerard C Krijger, Remco de Bree, Stefan M Willems, Bart de Keizer

Department of Head and Neck Surgical Oncology, Utrecht Cancer Center, University Medical Center Utrecht, P.O. Box 85500, Heidelberglaan 100, Utrecht, 3508 GA, The Netherlands. ., Department of Head and Neck Surgical Oncology, Utrecht Cancer Center, University Medical Center Utrecht, P.O. Box 85500, Heidelberglaan 100, Utrecht, 3508 GA, The Netherlands., Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands., Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands.