2017 Section 7 Green Book

Reprinted by permission of JAMA Otolaryngol Head Neck Surg. 2016; 142(1):79-85.

Review

Use of 18 F-Fludeoxyglucose–Positron Emission Tomography/Computed Tomography for Patient Management and Outcome in Oropharyngeal Squamous Cell Carcinoma A Review

Mehdi Taghipour, MD; Sara Sheikhbahaei, MD, MPH; Wael Marashdeh, MD; Lilja Solnes, MD; Anna Kiess, MD, PhD; Rathan M. Subramaniam, MD, PhD, MPH

Supplemental content at jamaotolaryngology.com

18 F-fludeoxyglucose–positron emission tomography/computed tomography (FDG-PET/CT) has been performed widely in diagnosis and management of patients with oropharyngeal squamous cell carcinoma (OPSCC). This review summarizes the literature on this tool in the management of these patients. The use of FDG-PET/CT helps in accurate staging of primary tumor, nodal involvement, and distant metastasis of patients with OPSCC. Contrast-enhanced FDG-PET/CT combines high-resolution CT and functional FDG-PET, providing the optimum imaging information for patient management. Using contrast-enhanced PET/CT leads to a combined anatomic and metabolic approach to radiation therapy planning in OPSCC. Moreover, PET/CT not only is a good modality for therapy assessment but also is a powerful tool in early recurrence detection of OPSCC. Finally, the PET/CT parameters provide survival information in patients with OPSCC; however, further studies are needed to introduce a scoring system to use clinically for prognosis prediction.

Author Affiliations: Author affiliations are listed at the end of this article. Corresponding Author: Rathan M. Subramaniam, MD, PhD, MPH, Russell H. Morgan Department of Radiology and Radiology Science, Johns Hopkins Medical Institutions, 601 N Caroline St, JHOC 3235, Baltimore, MD 21287 ( rsubram4@jhmi.edu ).

JAMA Otolaryngol Head Neck Surg . 2016;142(1):79-85. doi: 10.1001/jamaoto.2015.2607 Published online November 19, 2015.

H ead and neck cancers are the sixth most common malig- nant neoplasms globally. Despite an improvement in can- cer detection and treatmentmethods, they are still a sub- stantial healthcareproblem 1 andapproximately650 000newcases aredetectedannually,with350 000deaths yearlyworldwide. 2 Oro- pharyngeal cancer is the most common subtype of head and neck cancers, andoropharyngeal cancers account for approximately 25% of head and neck cancers in the United States. 3 Almost all oropha- ryngeal cancers are squamous cell carcinomas (SCCs). 2 Smoking and alcohol use are themost important risk factors for oropharyngeal squamous cell carcinoma (OPSCC). Alcohol syner- gistically increases the carcinogenic effect of smoking. This carci- nogenic effect is dose dependent for both alcohol and smoking. Hu- man papillomavirus (HPV) infection, mainly HPV type 16, plays an important role in the etiology of head and neck cancers, especially OPSCC. 4 The incidence of HPV-related OPSCC has increased, and the palatine tonsils and base of the tongue are the most common sites of HPV-related head and neck cancers. Some studies have reported that as many as 72% of OPSCCs are positive for HPV. 5 Studies have shown that HPV-related squamous cell carcinoma (SCC) is epidemiologically, clinically, and biologically different from HPV-negative SCC. The former occurs more frequently in younger patients, predominantly in males and whites, and is asso- ciated with sexual behavior. 6 Human papillomavirus–related OPSCC is histologically different from HPV-negative disease, as it presents with higher mitotic rate, poor differentiation, no kerati- nization, and distinct basaloid appearance. Both prospective and

retrospective studies, as well as meta-analysis, have confirmed better survival rates in patients with HPV-related OPSCC com- pared with HPV-negative disease, either with surgical or nonsur- gical management. 7 18 F-fludeoxyglucose–positron emission tomography/ computed tomography (FDG-PET/CT) has been proven to be valuable in the management of many human solid tumors. 8,9 The purpose of this article was to review the literature to assess the value of FDG-PET/CT in the management of patients with OPSCC. A PubMed search was performed using the search terms “posi- tron emission tomography” or “PET” or “PET/CT,” “oropharyngeal neoplasm” or “oropharyngeal cancer,” “oropharyngeal squamous cell carcinoma,” “head and neck neoplasm,” “staging,” “therapy planing,” “therapy assessment,” “survival,” or “prognosis” without restriction or filter for all relevant articles published through December 31, 2014. Value of PET/CT in Primary Tumor Detection Uptake of FDG in primary tumors depends on variable factors in- cluding tumor type, size, proliferation rate, and ratio of viable vs ne- crotic cells. 10 The overall sensitivity and specificity of PET scans in detecting primary tumor is greater than 90%, especially if a con- trast CT scan is added to PET. 4 For primary tumor detection, CT and magnetic resonance imaging (MRI) effectively localize large tu- mors, but for small tumors PET is more effective 11 because of in-

(Reprinted) JAMA Otolaryngology–Head & Neck Surgery January 2016 Volume 142, Number 1

jamaotolaryngology.com

43