Radiomics analysis
The available staging CT imaging data were manually retrieved from the
institutional Picture archiving and communication system (PACS) system
and anonymized according to study protocol before being analyzed by the
Fondazione Policlinico Universitario “A. Gemelli” Radiomics lab of
Rome, Italy. Images were reviewed by two experienced pediatric
radiologists in consensus (PLD and DC) for quality check and NB were
manually contoured in their entire extension, defining a single region
of interest (ROI) per lesion on Eclipse Treatment Planning System
(Varian Medical Systems, Palo Alto, CA, USA). In figure 1 is shown an
example of NB lesion segmentation. All exams were acquired according to
standard CT protocols after intravenous administration of iodinated
contrast medium [26]. Equilibrium contrast phase was preferred for
image segmentation as the enhancement obtained better delineates the
main radiological features of NB [26, 27]. A subsequent independent
check of the segmentations has been provided by a radiation oncologist
belonging to the radiomics analysis team, in order to ensure ROI
integrity and anatomical coherence of the segmented volumes. Radiomics
features extraction was then performed using the MODDICOM R library,
according to the standard recommended by the image biomarker
standardisation initiative (IBSI), [16, 28].