Discussion
head and neck squamous cell carcinoma, HNSCC, tumor, EBV-related NPC
REGRESSION, TUMOR, RECURRENCE
To the best of our knowledge, this is the first study to evaluate the prognostic value of tumoral radiomic features from pre- and post-radiotherapy FDG PET images in patients with NPC. Texture parameters from pre- and post-treatment FDG PET scans had an impact on prediction of the prognosis of NPC patients. RSF models with clinical variables and radiomic PET features showed comparable prediction performance for PFS and OS to RSF models with clinical variables and conventional PET parameters.The prognostic value of textural features derived from pre-treatment FDG PET/CT imaging of head and neck squamous cell carcinoma (HNSCC) has been evaluated in several previous studies. Yoon et al. conducted univariate and multivariate regression analysis of 119 cases of HNSCC and reported that pre-treatment FDG PET radiomics contain prognostic informationAmong radiomic PET features, Δcode similarity (texture feature coding co-occurrence) was an important variable for PFS prediction and coarseness (neighborhood intensity-difference)Delta radiomic features on serial images are longitudinal changes in radiomic features and were introduced to assess treatment response noninvasively when using various imaging modalities to assess various cancersOur study has several limitations. First, the study was conducted in a relatively small number of subjects at a single center. Further study with more subjects in multiple centers is needed to develop a more precise predictive model of the survival of NPC patients and generalize the model. We intended to assess the potential prognostic power of tumor radiomic features in this preliminary study. In addition, the follow-up period after definitive treatment in this retrospective study was restricted to 60 months, because most patients who had survived for 5 years without recurrence had no further clinical visits to our institution. Missing data in smoking history, EBV, and p16 status arise from retrospective study design may obscure clinical implication of the variables. Furthermore, pre-treatment plasma EBV deoxyribonucleic acid (DNA) is an established prognostic factor for EBV-related NPC