[18F]FDG PET/CT in head and neck squamous cell carcinoma: a head-to-head between visual point-scales and the added value of multi-modality imaging

Abstract

Background Head and neck squamous cell carcinoma (HNSCC) represents the 6th leading cancer worldwide. In most cases, patients present a locally advanced disease at diagnosis and non-surgical curative treatment is considered the standard of care. Nowadays, [18F]FDG PET/CT is a validated tool in post-treatment evaluation, with a high level of evidence. However, in order to standardize imaging response, several visual scales have been proposed with none of them approved yet. The study aim is a head-to-head comparison between the diagnostic performance of the Hopkins criteria, Deauville score and the new proposed Cuneo score, to establish their prognostic role. Secondly, we investigate the possible added value of semiquantitative analysis and morphological data. Methods We performed a retrospective analysis on histologically proven HNSCC patients who underwent baseline and response assessment [18F]FDG PET/CT. Post-treatment scans were reviewed according to Hopkins, Deauville, and Cuneo criteria, assigning a score to the primary tumor site and lymph nodes. A per-patient final score for each scale was chosen, corresponding to the highest score between the two sites. Diagnostic performance was then calculated for each score considering any evidence of locoregional progression in the first 3 months as the gold standard. Survival analysis was performed using the Kaplan Meier method. SUVmax and its delta, as well as the product of diameters of the lymph node with the highest uptake at post-treatment scan, if present, were calculated. Results A total of 43 patients were finally included in the study. Sensitivity, specificity, PPV, NPV and accuracy were 87%, 86%, 76%, 92% and 86% for Hopkins score, whereas 93%, 79%, 70%, 96%, and 84% for Deauville score, respectively. Conversely, the Cuneo score reached the highest specificity and PPV (93% and 78%, respectively) but the lowest sensitivity (47%), NPV (76%), and accuracy (77%). Each scale significantly correlated with PFS and OS. The multivariate analysis revealed the Cuneo criteria and the product of diameters as prognostic factors for PFS. Conclusions Each visual score statistically correlated with prognosis thus demonstrating the reliability of point-scale criteria in HNSCC. The novel Cuneo score showed the highest specificity, but the lowest sensibility compared to Hopkins and Deauville criteria. Moreover, combining visual analyses with morphological data extracted from PET/CT could support the evaluation of doubtful cases.