Evaluating the Repeatability of MR-Derived Radiomic Features During Radiotherapy for Locally Advanced Cervical Cancer
Objectives:
Radiomics extract quantitative information from images
This information can be utilised to help predict treatment response or aid diagnosis
Prior to clinical implementation, radiomic features require assessment of repeatability
Temporal repeatability remains under researched [1]
This study aims to assess temporal repeatability of MR-derived radiomic features
Materials/Methods:
Materials:
Ten patients with locally advanced cervical cancer
Three visits, weeks 1, 3 and 5 of treatment
Two T2W MRI scans acquired per visit
Cervix-uterus and visible tumour delineated on each scan
Radiomic Feature Extraction:
Pre-processing was achieved via histogram matching normalisation
Radiomic Features were extracted using PyRadiomics (v3.0.1a)
An IBSI compliant open-source software
Repeatability Assessment:
Repeatability was assessed via intra-class correlation coefficient; ICC[2,1]
With scans as targets and contours as raters
Results:
Across all visits;
74.8% (cervix-uterus) 56.4%(visible tumour) of features showed excellent reliability (ICC > 0.9)
20.9% (cervix-uterus) 29.6%(visible tumour) good (0.75–0.9) 5.0% (cervix-uterus) 11.5% (visible tumour) moderate (0.5–0.75)
0.9% (cervix-uterus) 1.9% (visible tumour) features were labelled as poorly reliable
Systematic increases in repeatability across time were noted for the cervix-uterus, but not for the visible tumour, Table 1, Figure 1
Discussion/Future Work:
The majority (>90%) radiomic features are repeatable; denoted by an ICC > 0.5, Table 1
Features derived from the tumour less repeatable than those derived from the cervix-uterus
Radiomic feature repeatability changes across the treatment timeline, Figure 1
Longitudinal increase in cervix-uterus feature repeatability is theoretically driven by the shrinkage of the tumour
Future work for this project will establish an alternate feature selection pipeline which incorporates temporal information