372P - Effectiveness of HAN-MI-RADS (head and neck molecular imaging-reporting and data system) criterion in head and neck squamous cell carcinoma post concurrent chemoradiotherapy

Background

Post concurrent chemo-radiotherapy (CRT) response assessment in locally advanced head and neck squamous cell carcinoma (HNSCC) has been critical to decide further treatment. Morphological response assessment was challenging due to prevailing post-radiation changes. While, molecular response methods have been encouraging. Nonetheless, heterogeneity in various molecular criteria need further clarifications. This study aims to propose and evaluate effectiveness of a semi-quantitative molecular response criterion to predict recurrence and survival.

Methods

A five points HAN-MI-RADS criterion was proposed by the two ≥ 15 yrs experienced Nuclear Medicine physicians and PET/CT of locally advanced HNSCC patients (n-83) post CRT at 3 months were reanalyzed. Histopathology examination (HPE) at 3 months and HPE/clinical/ imaging outcome on follow-up was taken as standard for disease status. Diagnostic statistics, disease free survival (DFI) and overall survival (OS) were calculated. A comparison with Hopkins score was also done with ROC analysis.

Results

Metastasis was developed in 11/83 patients (13.3%) at 3 months evaluation. Of 72 patients, 39, 2 and 31 patients had complete response (Score 1, 2, 3A), equivocal response (score 3B), and partial response (Score 4, 5) as per HAN-MI-RADS. Per patient sensitivity, specificity, PPV, NPV and accuracy for predicting loco-regional disease up to one year and two years was 93.3%, 92.5%, 90.3%, 94.9%, 92.9% and 84.9%, 91.9%, 90.3%, 87.2%, 88.6% respectively. One year and two years DFI for each HAN-MI-RADS score showed statistically significant difference while it was not for OS. The ROC curve analysis showed significantly better disease outcome predictability of HAN-MI-RADS (AUC 0.884) than Hopkins (AUC 0.699).

Conclusions

A five points HAN-MI-RADS criterion was found promising for response assessment with less equivocal results and statistically significant higher AUC than Hopkins for loco-regional recurrence prediction. Further, prospective studies analysis with larger patients will prove its clinical validity.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.