Adenoid cystic carcinoma (ACC) is a rare tumor entity with a yearly incidence of 3-5 cases per million. ACC arises in the major salivary glands and more often in the minor salivary glands of the oropharynx, lip, nasopharynx, oral cavity, nasal cavity, paranasal sinus, larynx and tracheobronchial tree. ACC is characterized by frequent local recurrences and distant metastasis, mainly to lungs. 18F-FDG PET/CT is considered to be a viable tool to assess ACC at initial presentation. However, FDG uptake in ACC is lower than in squamous cell carcinoma (SCC) and not all ACC lesions show detectable FDG uptake. So, it is necessary to find another effective way to detect ACC and its metastases. As in known, PSMA is highly expressed in salivary glands, and Wim van Boxtel et al had demonstrated high PSMA-ligand uptake in a patient with recurrent and metastatic ACC using 68Ga-PSMA PET/CT. 68Ga-PSMA has been developed as a targeting imaging agent widely used in prostate cancer in prostate cancer. Thus, this prospective study is going to investigate whether 68Ga-PSMA PET/CT may be superior for diagnosis, therapy response assessment and follow-up of ACC than 18F-FDG PET/CT. Furthermore, peptide receptor radionuclide therapy has been widely used in the treatment of prostate cancer lesions that showed high PSMA uptake on 68Ga-PSMA PET/CT, we'll try to assess the safety and therapeutic response to 177Lu-EB-PSMA-617 in patients with ACC.
Adenoid cystic carcinoma (ACC) accounts for 24% of salivary gland malignant tumors, is characterized by frequent local recurrences and distant metastasis, mainly to lungs. Considering its origination from salivary glands, an organ with intense physiological uptake of 68Ga-PSMA-617, this study aims to evaluate 68Ga-PSMA-617 uptake in local recurrent or metastatic ACC in comparison with 18F-FDG uptake in the same patients, and assess the feasibility of 177Lu-EB-PSMA-617 treatment in patients with the advanced ACC.