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

BACKGROUND: 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. RESULTS: 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. CONCLUSION: 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

Intraoral ultrasonography to measure tumor thickness of oral cancer : A systematic review and meta-analysis

Early oral cancer is preferably treated by surgery. Its complete removal is essential for locoregional control and disease-free survival. Inadequate resection margins require adjuvant therapy such as re-resection or (chemo)radiation, that causes extra morbidity and oral discomfort. Intraoral ultrasonography (US) is reported to be of value in determining tumor thickness. Intraoperative visualization of the tumor may facilitate the resection and ensure adequate surgical margins. Furthermore, accurate prediction of tumor thickness could help determine the treatment strategy of the clinically node-negative neck, as thickness and depth of invasion are predictors of cervical metastasis as well as prognosticators of survival. The 8th edition of the American Joint Committee on Cancer staging system for oral squamous cell carcinoma has included depth of invasion as parameter for cT-stage. The aim of this review is to analyze the accuracy of intraoral US in determining tumor thickness in oral cancer. A systematic search was conducted, and the quality of the included papers was assessed using the QUADAS-2 tool for diagnostic accuracy studies. Subsequently, a meta-analysis was performed on the available individual participant data of 240 patients. Most of the twelve included studies focused on T1-2 tongue cancer (n = 129). Meta-analysis showed a high correlation in tumor thickness within this subgroup as measured by intraoral US and histopathology (r = 0.82, p <.001), with minor overestimation of 0.5 mm on US. It is concluded that intraoral US is very accurate in determining tumor thickness in early oral tongue cancer