⁶⁸Ga-PSMA-11 PET/CT Imaging Of Physiological Tracer Distribution Characteristics In The Head And Neck And Its Potential Application In Salivary Glands

Part ? Physiological Tracer Distribution Characteristics of ⁶⁸Ga-PSMA-11 PET/CT in Head and NeckObjective:To qualitative and semiquantitative analyze the physiological tracer distribution characteristics of ⁶⁸Ga-PSMA-11 PET/CT imaging in head and neck,and to explore its potential application value in head and neck diseases.Methods:From January 2019 to February 2020,68 patients?age:41-86 years,average age 65.7 years?who underwent ⁶⁸Ga-PSMA-11 PET/CT imaging for prostate cancer detection and staging were retrospectively analyzed.The physiological distribution of tracers in head and neck was analyzed by visual analysis,and the level of tracers uptake was semiquantitatively analyzed by measuring the maximum standardized uptake value?SUVmax?at each location.Results:The physiological distribution of ⁶⁸Ga-PSMA-11 is mainly located in the lacrimal gland,parotid gland,submandibular gland,sublingual gland,nasal mucosa,pharyngeal wall,soft palate,lip,supraglottic larynx and thyroid.The uptake of imaging agent varies with the location of gland.The mean SUVmax±standard deviation varied:brain0±0.1?0.0⁰.2?;lacrimal gland 7.4±3.4?2.3¹7.3?;parotid gland12.6±3.7?5.5²6.6?;submandibular gland 14.2±2.8?5.6²5.9?;sublingual gland 5.5±2.9?1.5¹3.7?;nasal mucosa 5.1±1.9?1.8¹2.2?;pharyngeal wall 4.6±1.4?1.6⁸.4?;soft palate 2.7±0.8?1.0⁴.9?;lip3.0±1.3?1.2⁷.5?;supraglottic larynx 3.5±1.2?1.3⁷.0?;and thyroid1.4±0.5?0.6².7?.Among them,lacrimal glands and major salivary glands had the highest uptake of imaging agents,followed by nasal mucosa,pharyngeal wall,supraglottic larynx,lip,and soft palate.The uptake of imaging agents in thyroid is low.There was almost no uptake of imaging agent in brain parenchyma.There were different intra-individual differences in the uptake of paired gland imaging agents.The mean SUVmax±standard deviation of within-subject coefficient of variation varied:lacrimal gland?9.6±7.8?%?0³5.4%?,parotid gland?8.3±7.6?%?0.6³0.4%?,submandibular gland?8.5±6.4?%?0²6.1%?,sublingual gland?12.5±8.4?%?0³6.7%?,pharyngeal wall?7.5±5.9?%?0²2.3%?.Conclusion:⁶⁸Ga-PSMA-11 PET/CT not only can clearly show the location and morphology of lacrimal gland and major salivary gland,but also can accurately locate and clearly depict the anatomical location of minor salivary gland in head and neck,which is expected to become a new technology of head and neck gland imaging.Based on the physiological distribution and abnormal uptake of ⁶⁸Ga-PSMA-11 in brain and thyroid gland,⁶⁸Ga-PSMA-11 PET/CT is expected to be a potentially useful imaging tool for the evaluation of brain tumors and thyroid lesions.Part ? Potential Applications of ⁶⁸Ga-PSMA-11 PET/CT in the Evaluation of Salivary Gland Uptake Function: Preliminary Observations and Comparison with ^99mTcO₄^-Salivary Gland ScintigraphyObjective: To preliminarily evaluate the feasibility and potential of using ⁶⁸Ga-PSMA-11 PET/CT in evaluating the function of salivary glands in comparison with ^99mTc-pertechnetate(^99mTcO₄^-)salivary gland scintigraphy.Methods: A retrospective study was performed in 15 patients with different degrees of xerostomia and suspected salivary gland dysfunction.Each patient underwent ⁶⁸Ga-PSMA-11 PET/CT and ^99mTcO₄^-salivary gland scintigraphy,and the findings of both scans were compared.Results: This study included 4 patients with Sjogren's syndrome,10 patients with head and neck tumor after radiotherapy and chemotherapy,and 1 patient with parotid space occupying lesion after operation.The results of the ⁶⁸Ga-PSMA-11 PET/CT and ^99mTcO₄^-salivary gland scintigraphy were consistent in 12 patients?80%?and were inconsistent in the remaining patients?20%?.For 5?33.3%?patients,⁶⁸Ga-PSMA-11 PET/CT provided more information than did ^99mTcO₄^-salivary gland scintigraphy.Additionally,⁶⁸Ga-PSMA-11 PET/CT corrected the misdiagnosis by ^99mTcO₄^-salivary gland scintigraphy for 1 patient.Conclusion: ⁶⁸Ga-PSMA-11 PET/CT is a potentially useful imaging tool for evaluating the function of salivary glands.⁶⁸Ga-PSMA-11 PET/CT can be a promising supplement to ^99mTcO₄^-salivary gland scintigraphy,and its clinical value deserves further study.