Accuracy of [¹⁸Fluorine]-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography-Computed Tomography Response Assessment Following (Chemo)radiotherapy for Locally Advanced Laryngeal/Hypopharyngeal Carcinoma

Abstract

INTRODUCTIONThe accuracy of response assessment positron emission tomography (PET)-computed tomography (CT) following radiotherapy with or without chemotherapy for laryngeal/hypopharyngeal squamous cell carcinoma is uncertain.METHODSIn all, 35 patients with laryngeal or hypopharyngeal squamous cell carcinoma who were treated between 2009 and 2014 with (chemo)radiotherapy were identified. The accuracy of response assessment PET-CT was made by correlation with clinical follow-up and pathological findings.RESULTSOf the 35 patients, 20 (57%) had an overall complete metabolic response. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for response assessment [18Fluorine]-fluoro-2-deoxy-d-glucose (FDG) PET-CT for primary and nodal sites, respectively, were 100%, 73%, 46%, and 100% and 83%, 95%, 83%, and 95%.CONCLUSIONSResponse assessment FDG PET-CT following (chemo)radiotherapy for laryngeal and hypopharyngeal carcinomas has a high NPV for both primary site and lymph nodes and can be used to guide treatment decisions. The PPV of residual FDG uptake at the primary tumour site is limited and requires examination and biopsy confirmation.

Second-look PET-CT following an initial incomplete PET-CT response to (chemo)radiotherapy for head and neck squamous cell carcinoma

“…When there is doubt about clinical and radiological response a 'second-look' PET-CT can be used to spare patients unnecessary surgical intervention Introduction Accurate response assessment following (chemo)radiotherapy for head and neck squamous cell carcinoma (HNSCC) is required to select patients for clinical follow up from those who require surgical treatment. The difficulty in determining the significance of residual masses post-treatment limits the utility of anatomical imaging with CT and/or MRI [ The negative predictive values (NPV) of response assessment FDG PET-CT have been shown to be excellent, identifying patients who do not require surgical intervention [6][7][8][9][10][11][12][13][14]. This applies even in the context of metabolically inactive residual masses [8; 15].…”

A Review of Controversial Issues in the Management of Head and Neck Cancer: A Swiss Multidisciplinary and Multi-Institutional Patterns of Care Study—Part 2 (Radiation Oncology)

“…In other words, 18 FDG-PET/CT is an ideal modality to rule out residual disease after (chemo)radiotherapy. Recent studies demonstrated further increased accuracy with delayed image acquisition around 16 weeks after treatment with NPVs reaching 100% (64–66). On the other hand, the access to 18 FDG-PET/CT in low-cost setting is not always warranted, and morphologic imaging alone with MRI or CT should be relied on.…”