Applicability of PSMA PET/CT in the Evaluation of Adenoid Cystic Carcinoma: a Systematic and Clinical-comparative review

• Grant number: 25/13325-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: July 31, 2026
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: Elba Cristina Sá de Camargo Etchebehere
• Grantee: Lucas Augusto de Freitas de Pinho
• Host Institution: Centro de Hematologia e Hemoterapia (HEMOCENTRO). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/10265-8 - Cancer Theranostics Innovation Center (CancerThera), AP.CEPID

Abstract

Adenoid Cystic Carcinomas (ACC) are rare, aggressive malignant tumors that originate in the body's secretory glands, accounting for 1% of head and neck carcinomas and 10% of salivary gland neoplasms. ACC is characterized by slow, indolent growth that causes nonspecific symptoms in patients, delaying diagnosis in many cases. It is also characterized by early perineural invasion, low rate of involvement in locoregional lymph nodes and high rate of distant metastases. The standard treatment for uncomplicated primary ACC is surgical resection followed by postoperative radiotherapy, but there is no consensus regarding systemic or targeted therapy for recurrent, unresectable, and metastatic cases.Diagnostic results have already shown promise with the use of 18F-FDG PET/CT for assessing the extent of the disease. The discovery of Prostate-Specific Membrane Antigen (PSMA) expression in ACC has expanded investigations into the theranostic potential of nuclear medicine, and possibilities are being evaluated for the use of 18F-PSMA PET/CT as a diagnostic and, potentially, therapeutic method.The objectives of this research are to evaluate the applicability of PSMA PET/CT compared to FDG PET/CT for diagnosis and possible theranostic use. To that end, a systematic review will be conducted using studies that applied both methods in patients with ACC. The data will then be correlated with the results of the ongoing clinical trial at CEPID Cancerthera, which evaluates both radiopharmaceuticals in patients with recurrent ACC.