Abstract
2043
Objectives: To review the evolving role of PET imaging in clinical assessment and management of HNC and its ability to gather additive information post-RT treatment.
Methods: Several large scientific databases, including PubMed, Web of Science, and Google Scholar, were used to accumulate review articles and scientific communications relating to the clinical PET practices in imaging benign and malignant head and neck disorders. Next, review articles and scientific studies were compiled from the aforementioned databases to accumulate a comprehensive body of literature. Specifically, articles will encompass today’s knowledge of head and neck disorders as derived from PET studies. Importantly, a large subset of such studies will reflect the most recent innovations in the molecular imaging with PET of head and neck disorders.
Results: 18F-fluoro-deoxyglucose (FDG) is a radiolabeled glucose analog that is the most frequently used radiotracer in clinical practice. FDG is a useful marker for metabolically active cells, such as cancer and inflammatory cells, which use glucose as an energy source for their metabolic needs. Several studies have displayed the vast utility of FDG-PET in a wide array of pathologies, including malignancy in the head and neck area. However, the complete/optimal utilization of FDG PET in the management of head and neck cancer (HNC) is still not fully employed.One area where PET/CT has gained traction in is its role in detecting tumors and metastases of the head and neck region, especially in head and neck squamous cell carcinoma (HNSCC), which is the sixth most encountered cancer. Multiple authors have concluded that clinicians should utilize PET/CT in their treatment plans for their HNC patients. PET not only provides both functional and anatomical data, but also is superior to other imaging modalities due to its high positive and negative predictive values to detect primary tumors and distant metastasis. Furthermore, radiation therapy (RT) is a mainstay treatment for head and neck cancer, but may inadvertently disrupt tissues peripheral to the target. FDG PET has recently been emerging as a tool to diagnose and quantify RT induced inflammation in non-target tissues. Our lab has demonstrated the application of using FDG-PET/CT volumetric parameters to diagnose and quantify vasculitis of the left coronary artery and aortic arch, and incidental damage of oral tissues, like the parotid glands, after photon, proton, or combination RT. Conclusion: Many studies have looked at the impact of PET on tumor staging, however, there is still more future work to be done to fully characterize the use of PET in head and neck disorders. It is still unclear which quantification methods have the best prognostic utility to predict outcomes. Some retrospective studies have suggested the use of SUVmax, while the PET parameters SUVmean, metabolic tumor volume (MTV), or total lesion glycolysis (TLG) have recently been introduced to show better correlation with prognosis. There is a respectable amount of retrospective literature evaluating PET for staging and diagnosis of HNC, however there is a need for a greater number of prospective studies evaluating critical, additive information brought to light by PET (i.e., diagnosis and quantification of RT induced inflammatory complications in patients undergoing treatment for HNC) as this would further solidify PET as a powerful instrumental imaging modality with vast clinical application.