CT radiomics nomogram predicts pathological response after induced chemotherapy and overall survival in patients with advanced laryngeal cancer: A single-center retrospective study

Abstract

Purpose: This study aimed to develop a radiomics nomogram to predict pathological response (PR) after induction chemotherapy (IC) and overall survival (OS) in patients with advanced laryngeal cancer (LC).

Methods: This retrospective study included patients with LC (n = 114) who had undergone contrast computerized tomography (CT); patients were randomly assigned to training (n = 81) and validation cohorts (n = 33). Potential radiomics scores were calculated to establish a model for predicting the PR status using least absolute shrinkage and selection operator (LASSO) regression. Multivariable logistic regression analyses were performed to select significant variables for predicting PR status. Kaplan-Meier analysis was performed to assess the risk stratification ability of PR and radiomics score (rad-score) for predicting OS. A prognostic nomogram was developed by integrating radiomics features and clinicopathological characteristics using multivariate Cox regression. All LC patients were stratified as low- and high-risk by the median CT radiomic score, C-index, calibration curve. Additionally, decision curve analysis (DCA) of the nomogram was performed to test model performance and clinical usefulness.

Results: Overall, PR rates were 45.6% (37/81) and 39.3% (13/33) in the training and validation cohorts, respectively. Eight features were optimally selected to build a rad-score model, which was significantly associated with PR and OS. The median OS in the PR group was significantly shorter than that in the non-PR group in both cohorts. Multivariate Cox analysis revealed that volume [hazard ratio, (HR) = 1.43], N stage (HR = 1.46), and rad-score (HR = 2.65) were independent risk factors associated with OS. The above four variables were applied to develop a nomogram for predicting OS, and the DCAs indicated that the predictive performance of the nomogram was better than that of the clinical model.

Conclusion: For patients with advanced LC, CT radiomics score was an independent biomarker for estimating PR after IC. Moreover, the nomogram that incorporated radiomics features and clinicopathological factors performed better for individualized OS estimation.

Keywords: chemotherapy; laryngeal; nomogram; pathological response; radiomics.

Figure 1

Workflow of CT radiomic score model development for predicting pathological response status and OS in advanced LC patients. CT, computed tomography; OS, overall survival; LC, laryngeal cancer.

Figure 2

Predictive pathological response status performance of radiomic score in (A) training and (B) validation cohorts.

Figure 3

Violin plots showing that the radiomic score (rad-score) of the non-pathological response (PR) group is substantially higher than that of the PR of LC patients who underwent IC therapy in (A) training and (B) validation cohorts. Red represents a high rad-score in the non-PR group, and blue represents a low rad-score in the PR group.

Figure 4

Kaplan–Meier estimates of overall survival with the associated 95% confidence intervals. Patients were stratified by pathological response (PR) status in (A) training and (B) validation cohorts. Blue and red lines represent patients in PR and non-PR groups, respectively. Patients were stratified by radiomic scores in (C) training and (D) validation cohorts. Blue and red lines represent patients in lower and higher risk groups, respectively.

Figure 5

(A) Nomogram for predicting the overall survival (OS) of advanced laryngeal cancer (LC) patients. For each patient, lines are drawn downward to assess the points received from the four prognostic factors in the nomogram. The sum of these points is shown on the “Total points” axis. A line is drawn downward to determine the 1-, 2-, and 3-year OS of LC patients. (B) Calibration plot for the internal validation of the nomogram. The Y-axis exhibits actual survival. The X-axis exhibits nomogram-estimated survival. The dotted line (45° diagonal line) signifies full agreement between actual and observed probabilities. (C) Clinical net benefit of the nomogram, radiomic score, and other clinical features (including T, N, and Volume). *P =0.04, **P =0.008.