[Prediction of recurrence-free survival of T1 glottic carcinoma based on enhanced CT anterior commissure invasion and tumor volume].

Objective: To investigate the recurrent predictive value of morphologic features based on enhanced CT anterior commissure invasion (ACI) and tumor volume (TV) in patients with T1-stage glottic cancer (GC) following larynx-preserving surgery. Methods: The clinical and enhanced CT images of patients with T1-staging GC treated with larynx-preserving surgery in Tianjin First Central Hospital from January 2015 to December 2019 were retrospectively analyzed. According to the postoperative follow-up results, they were divided into recurrence group and non-recurrence group. The morphological characteristics of tumors, including ACI status and quantitative characteristics (length, thickness, volume), were evaluated on enhanced CT images. The optimal cut-off values of each quantitative parameter for evaluating recurrence were determined by receiver operating characteristic (ROC) curve analysis, and the single or pairwise morphological characteristics with statistically significant differences (P<0.05) between groups were included in multivariate Cox regression to analyze the influencing factors of postoperative recurrence-free survival(RFS) and build morphological feature models. Harrell's concordance index (C-index) was used to compare the predictive power of morphological association features with the AJCC-T1 staging system for postoperative recurrence. Calibration curves and decision curve analysis (DCA) were used to assess the calibration and clinical suitability of the model, respectively. Results: A total of 147 patients were included, the ratio of male to female was 11∶1, and the age was (62.6±8.7) years. The median follow-up time was 44 months, and there were 25 cases in relapse group and 122 cases in non-relapse group. ACI combined with TV, length combined with TV, thickness combined with TV were correlated with RFS (P<0.05). ACI+TV≥118.55 mm3 was a risk factor for RFS (HR=4.17, 95%CI:1.85-9.37, P=0.002). The C- index for predicting recurrence based on the combined morphological features of ACI and TV was higher than that of AJCC-T1 staging [0.73 (95%CI: 0.62-0.84) vs 0.65 (95%CI: 0.55-0.74), Z=2.84, P=0.004]. Calibration curves showed good agreement between model-predicted recurrence-free survival and actual recurrence-free survival, and DCA results indicated good clinical net benefit from the model. Conclusions: Morphological characteristics of ACI combined with TV are associated with RFS after larynx-preserving surgery in patients with T1-staging GC, and anterior commissure invasion with larger tumor volume (ACI+TV≥118.55 mm3) at initial treatment are risk factors for postoperative recurrence.