The value of detailed MR imaging report of primary tumor and lymph nodes on prognostic nomograms for nasopharyngeal carcinoma after intensity-modulated radiotherapy

Radiother Oncol. 2019 Feb:131:35-44. doi: 10.1016/j.radonc.2018.11.001. Epub 2018 Dec 20.

Abstract

Purpose: To establish effective prognostic nomograms using clinical features and detailed magnetic resonance imaging (MRI) findings for primary tumor and regional lymph nodes after intensity-modulated radiotherapy (IMRT) in patients with nasopharyngeal carcinoma.

Method: The nomogram for overall survival (OS) was based on a retrospective study of 595 patients who underwent IMRT at Sun Yat-sen University Cancer Center from 2010 to 2012. The predictive accuracy and discriminative ability of our nomogram models were determined by concordance index and calibration curve, and were compared with the nomogram models combining clinical features with tumor-node-metastasis (TNM) classification. The results were validated using bootstrap resampling and a cohort study of 241 patients. The same data cohort was used to predict the progress-free survival (PFS) of nasopharyngeal carcinoma with 3:1 training cohort (N = 558) and validation cohort (N = 278).

Results: The following factors were assembled into our prognostic survival nomogram models: Age, Epstein-Barr virus DNA copy number before treatment (EBV_DNA_CN), tensor veli palatini (TVP) involvement, musculus pterygoideus lateralis (MPL) involvement, prestyloid space (PS) involvement, prevertebral space (PVS) involvement, base of sphenoid bone (BOSB) involvement, paranasal sinus (PNS) involvement, the laterality of Ⅱ (Ⅱ_laterality), the laterality of retropharyngeal lymph node (RPLN_laterality), nodal grouping (NG), extranodal neoplastic spread (ENS), contrast-enhancing rim (CER) and Nodal_number. The calibration curves showed good agreement between nomogram-predicted and actual survival. Our nomogram models for OS and PFS, provided better results than the nomogram models combining clinical features with TNM classification. Results were further confirmed in the validation set.

Conclusion: Detailed MRI findings of primary tumor and regional lymph nodes can improve the performance of prognostic nomograms for patients with nasopharyngeal carcinoma.

Keywords: Magnetic resonance imaging; Nasopharyngeal neoplasms; Nomograms; Survival analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Female
  • Humans
  • Lymph Nodes / diagnostic imaging
  • Lymph Nodes / pathology
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Nasopharyngeal Carcinoma / diagnostic imaging*
  • Nasopharyngeal Carcinoma / pathology
  • Nasopharyngeal Carcinoma / radiotherapy*
  • Nasopharyngeal Neoplasms / diagnostic imaging*
  • Nasopharyngeal Neoplasms / pathology
  • Nasopharyngeal Neoplasms / radiotherapy*
  • Neoplasm Staging
  • Nomograms*
  • Prognosis
  • Proportional Hazards Models
  • Radiotherapy, Intensity-Modulated / methods
  • Reproducibility of Results
  • Retrospective Studies
  • Risk Assessment