1112PD - Efficacy evaluation of optimal patient selection for hypopharyngeal cancer organ preservation therapy using MRI-derived radiomic signature: Bi-institutional propensity score matched analysis

Abstract

BackgroundEarly loco-regional failure (LRF) after organ preservation therapy (OPT) varies widely for hypopharyngeal squamous cell carcinoma (HPSCC) patients. We aim to develop and validate a MRI-derived radiomic signature RS for the prediction of 1-year LRF in HPSCC treated with OPT, and investigate its efficacy between OPT and total laryngectomy (TL) cohort. MethodsA total of 3912 MRI-based radiomic features (RF) of pretreatment tumors were obtained from 370 HPSCC patients, including OPT cohort1 (OPT1; n=186), OPT cohort2 (OPT2; n=88), and TL cohort (TLc; n=96). Variational autoencoder (VAE), trained with symmetric two encoded and decoded layers of neural network was applied to reduce the dimensionality of original RF to 128 VAE-RF. Least absolute shrinkage and selection operator with 10-fold cross validation performs features selection and constructs RS to predict 1-year LRF events in OPT1, which was validated in OPT2 and TLC. Harrell’s C-index was used to evaluate the discriminative ability of RS. Optimal cut-point for dichotomized RS risk category was determined via Youden index. Pair-wise propensity score matching (caliper 0.2) using pre-treatment variables (age, gender, TNM stage) was applied to compare the impact of OPT and TL under different RS risk categories. ResultsThe RS yielded 1000 times bootstrapping corrected C-index of 0.753, 0.745 and 0.398 in the OPT1, OPT2 and TLC, respectively. Dichotomized risk category using Youden cut-point of RS yielded 1 year LRF predictive accuracy of 71.12%, 70.41%, and 41.74% in OPT1, OPT2 and TLC, respectively. In RS-high risk group, OPT were associated with poor progression-free survival (PFS, HR: 1.752, p=0.032), while in RS-low risk group, OPT did not deteriorate the PFS (HR: 0.774, p=0.416). ConclusionsThe RS-based model provides a novel to predict 1-year LRF and survival in patients with HPSCC who received OPT. The prediction performance discrepancy of MRI-derived RS in TLC also emphasizes the role of TL in RS-high risk group. Legal entity responsible for the studyThe authors. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.