Diagnosis, Staging, Radiation Treatment Response Assessment, and Outcome Prognostication of Head and Neck Cancers Using PET Imaging

Abstract

Diagnosis: 18 F-FDG PET/CT is recommended before pan-endoscopy or other invasive procedures in the workup for head and neck squamous cell carcinoma (HNSCC) of unknown primary. Staging: 18 F-FDG PET/CT is recommended in patients with locoregionally advanced HNSCC given its high level of accuracy in detecting nodal disease and sensitivity for distant metastases. Radiation treatment response: 18 F-FDG PET/CT at 12 weeks after completion of definitive chemoradiation negates the need for planned neck dissection in up to 80% of cases without compromising overall survival. Outcome prognostication: PET tracers of hypoxia are promising prognostic biomarkers in HNSCC that merit further validation.

Metabolic tumor volume and total lesion glycolysis as prognostic factors in head and neck cancer: Systematic review and meta‐analysis

“…18 F-fluorodeoxyglucose ( 18 F-FDG) positron-emission tomography (PET) is a widely used tool for staging, planning, and monitoring HNC, identifying both morphological and metabolic abnormalities within the tumor. [8][9][10] Lately, many easily obtainable PET parameters and their prognostic relevance in HNC are being studied. Maximum standardized uptake value (SUVmax) is a measurement widely used in clinical practice; nonetheless, many studies show conflicting results concerning its usefulness.…”

Prediction of Response in Head and Neck Tumor: Focus on Main Hot Topics in Research

“…To date the 2-deoxy-2-[18F]fluoro-D-glucose (FDG) positron emission tomography/computed tomography (PET/CT) is a standard diagnostic methodic used in HNC patients for staging, restaging, RT planning, and outcome evaluation (37,38). Several data published in literature underline how changes of neoplastic glucose metabolism, evaluated by FDG PET, are able to predict tumor response rates and oncological outcomes in several solid cancer (39). In particular as regards PET in HNC the major data are validated for SCCHN and nasopharyngeal cancer.…”

“…In this settings, PET/CT could help radiation oncologist for target delineation and in radiation planning (39). Moreover, it has been suggested that FDG is able to detect primary tumor site in about 25% of patients with unknown disease (40) and at baseline, it allows quantification of the tumor tracer uptake thus producing semiquantitative values that can be indicative of prognosis.…”

“…It has been suggested that the use of uptake time normalized tumor-to-blood SUV ratio (standardized uptake ratio, SUR) might remove most of these shortcomings improving test-retest stability and providing significantly better prognostic value compared to tumor SUV (39). However, more recently, other PET-based parameters have emerged as potentially valuable for the prognostic stratification in several oncologic diseases including HNC.…”

Is 68Ga-DOTA-FAPI a new arrow in the quiver of dose painting in radiation dose planning in head and neck cancers?

“…The concept of detecting the tumour and defining tumour cells with radioresistance was evaluated implementing different hypoxia-delineating radiotracers, namely [ 18 F]-FMISO, [ 18 F]-FAZA and [ 18 F]-HX4. For all three tracers, the tracer uptake correlated with the grade of hypoxia in the viable tumour cells [14]. Especially molecular imaging using the most promising hypoxia-related radiotracer [ 18 F]-HX4, it effectively demonstrates changes in hypoxia by detecting the extent of hypoxic cells in the tumour volume during radiotherapy [15].…”