Indications for PET/CT in the Head and Neck

Abstract

Head and neck cancer accounts for approximately 3% to 5% of all new cancer diagnoses in the United States with 40,000 new cases diagnosed each year [1]. These figures encompass cancers arising from the lip, oral cavity, nasal cavity, paranasal sinuses, pharynx, and larynx, of which the vast majority (90% to 95%) are squamous cell carcinomas arising from mucosal linings of the upper aerodigestive tract. Other, rare cancers that may involve the head and neck include salivary tumors, thyroid cancers, lymphoma, and melanoma.Early diagnosis and accurate staging are essential for treatment planning and can strongly influence prognosis. Likewise, early identification of tumor recurrence can often be treated with additional surgery or re-irradiation. A combination of history, physical exam, endoscopy, and tissue sampling has historically been the mainstay of diagnosis and staging. The use of crosssectional imaging (CT and MRI) has greatly improved staging and monitoring for disease recurrence. Small metastases and/or early recurrent disease, however, can still be missed [2].Functional imaging with 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can be used to fill these gaps and improve characterization of both primary tumors and metastatic disease. PET has been shown to be effective in the diagnosis of many different types of cancer, including head and neck squamous cell carcinoma (HNSCC) [3]; however, the poor spatial resolution of PET and the lack of anatomic landmarks can make exact localization of disease difficult. In addition, normal

Negative Predictive Value of Surveillance PET/CT in Head and Neck Squamous Cell Cancer

“…17 We also believe that PET/CT is best interpreted as a combined technique, with both components holding equal weight during interpretation. 2 Additionally, our findings are also dependent on the accuracy of a large clinical data repository. We did not attempt to analyze a subsets of patients on the basis of human papillomavirus status or therapeutic modalities; this is an area for further study.…”

“…1 A radiologic examination is crucial in staging patients, monitoring response to therapy, and conducting surveillance of treated disease. 2 CT, MR imaging, and PET have been used for these evaluations, with combined PET/CT showing greater accuracy than either PET or CT alone. 3 PET/CT has an overall 90% sensitivity in localizing recurrent disease and an 86% accuracy for finding residual disease.…”

“…[4][5][6][7] Current literature on PET/CT in HNSCC has focused on detection, staging, and monitoring response to therapy, while research in the area of posttreatment surveillance is limited. 2 To reduce both medical cost and the radiation dose to patients, identification of an efficient and effective surveillance scheme is critical, but there is no widely accepted protocol for the use of PET/CT in the surveillance of HNSCC, leading to the potential misapplication or overuse of this technique. 8 Previous literature has suggested that it is wasteful to perform PET/CT for HNSCC surveillance Ͼ24 months after the conclusion of therapy.…”

Multi detector computerized tomography scans aid in the staging of Head and Neck cancers

“…Tumor volume, lymph node infiltration distant metastases are the most important factors that influence the therapeutic approach and the prognosis of the patient with HNC 5,8 . Exact tumor staging is necessary for treatment planning, leading to reduced postoperative morbidity and tumor recurrence-associated mortality 9 . Sub mucosal extension cannot be sufficiently assessed by endoscopy and physical examination but can be evaluated with magnetic resonance imaging MRI and CT to a lesser extent 10,11 .…”

Nuclear Imaging in Dentistry -A novel modality to explore

“…PET/CT has also proved its utmost efficiency in diagnosis of head and neck carcinomas early in the course of the disease. However, it essentially aids in staging of the head and neck squamous cell carcinomas, detecting the unknown primaries and also monitoring the response to the treatment (Agarwal et al 2008, Mathews et al2011) PET/MRI is a fusion imaging technology that incorporates both MRI soft-tissuemorphological imaging and PET functional imaging. Due to its limited availability, technical issues (especially regarding attenuation correction and the strong magnetic field that do not allow PET transmission scans to be implemented with positron-emitting rod sources), and the lack of clinical studies; PET/MRI cannot be regarded as an established modality in routine clinical practice, but still a promising technology, with its clinical and scientific value yet to be defined (Nensa et al 2014).…”