Vulnerabilities of radiomic signature development: The need for safeguards

Radiother Oncol. 2019 Jan;130:2-9. doi: 10.1016/j.radonc.2018.10.027. Epub 2018 Nov 8.

Abstract

Purpose: Refinement of radiomic results and methodologies is required to ensure progression of the field. In this work, we establish a set of safeguards designed to improve and support current radiomic methodologies through detailed analysis of a radiomic signature.

Methods: A radiomic model (MW2018) was fitted and externally validated using features extracted from previously reported lung and head and neck (H&N) cancer datasets using gross-tumour-volume contours, as well as from images with randomly permuted voxel index values; i.e. images without meaningful texture. To determine MW2018's added benefit, the prognostic accuracy of tumour volume alone was calculated as a baseline.

Results: MW2018 had an external validation concordance index (c-index) of 0.64. However, a similar performance was achieved using features extracted from images with randomized signal intensities (c-index = 0.64 and 0.60 for H&N and lung, respectively). Tumour volume had a c-index = 0.64 and correlated strongly with three of the four model features. It was determined that the signature was a surrogate for tumour volume and that intensity and texture values were not pertinent for prognostication.

Conclusion: Our experiments reveal vulnerabilities in radiomic signature development processes and suggest safeguards that can be used to refine methodologies, and ensure productive radiomic development using objective and independent features.

Keywords: Head and neck cancer; Lung cancer; Radiomics; Safeguards; Signature development; Volume.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Head and Neck Neoplasms / diagnostic imaging*
  • Head and Neck Neoplasms / pathology
  • Head and Neck Neoplasms / radiotherapy*
  • Humans
  • Lung Neoplasms / diagnostic imaging*
  • Lung Neoplasms / pathology
  • Lung Neoplasms / radiotherapy*
  • Models, Biological*
  • Prognosis
  • Radiometry / methods
  • Radiometry / standards
  • Radiotherapy Planning, Computer-Assisted / methods*
  • Radiotherapy Planning, Computer-Assisted / standards
  • Software
  • Tumor Burden

Grant support