TY - JOUR T1 - RESISTing the Need to Quantify: Putting Qualitative FDG-PET/CT Tumor Response Assessment Criteria into Daily Practice JF - American Journal of Neuroradiology JO - Am. J. Neuroradiol. SP - 1978 LP - 1986 DO - 10.3174/ajnr.A6294 VL - 40 IS - 12 AU - J.G. Peacock AU - C.T. Christensen AU - K.P. Banks Y1 - 2019/12/01 UR - http://www.ajnr.org/content/40/12/1978.abstract N2 - SUMMARY: Tumor response assessments are essential to evaluate cancer treatment efficacy and prognosticate survival in patients with cancer. Response criteria have evolved over multiple decades, including many imaging modalities and measurement schema. Advances in FDG-PET/CT have led to tumor response criteria that harness the power of metabolic imaging. Qualitative PET/CT assessment schema are easy to apply clinically, are reproducible, and yield good prognostic results. We present 3 such criteria, namely, the Lugano classification for lymphoma, the Hopkins criteria, and the Neck Imaging Reporting and Data Systems criteria for head and neck cancers. When comparing baseline PET/CTs with interim or end-of-treatment PET/CTs, radiologists can classify the tumor response as complete metabolic response, partial metabolic response, no metabolic response, or progressive disease, which has important implications in directing further cancer management and long-term patient prognosis. The purpose of this article is to review the progression of tumor response assessments from CT- and PET/CT-based quantitative and semi-quantitative systems to PET/CT-based qualitative systems; introduce the classification schema for these systems; and describe how to use these rapid, powerful, and qualitative PET/CT-based systems in daily practice through illustrative cases.CMRcomplete metabolic responseD5PSDeauville 5-point scaleNI-RADSNeck Imaging Reporting and Data SystemsPDrelapsed/progressive diseasePERCISTPET Response Criteria in Solid TumorsRECISTResponse Evaluation Criteria in Solid TumorsWHOWorld Health OrganizationHNSCCaHead and Neck squamous cell carcinomaACRAmerican college of radiologyAUCappropriate use criteriaSCCasquamous cell carcinomaPPDproduct of the diametersSPDsum of the product of the diameters ER -