Poster Presentation NSW State Cancer Conference 2023

Global radiomic features from mammography for predicting difficult‑to‑interpret normal cases (#278)

Somphone Siviengphanom 1 , Ziba Gandomkar 1 , Sarah Lewis 1 , Patrick Brennan 1
  1. University of Sydney, Camperdown, NSW, Australia

This work aimed to investigate whether global radiomic features (GRFs) from mammograms can predict difficult-to-interpret normal cases (NCs). Assessments from 537 readers interpreting 239 normal mammograms were used to categorise cases as 120 difficult-to-interpret and 119 easy-to-interpret based on cases having the highest and lowest difficulty scores, respectively. Using lattice- and squared-based approaches, 34 handcrafted GRFs per image were extracted and normalised. Three classifiers were constructed:(i)CC and (ii)MLO using the GRFs from corresponding craniocaudal and mediolateral oblique images only, based on the random forest technique for distinguishing difficult- from easy-to-interpret NCs, and (iii)CC+MLO using the median predictive scores from both CC and MLO models. Useful GRFs for the CC and MLO models were recognised using a scree test. The CC and MLO models were trained and validated using the leave-one-out-cross-validation. The models’ performances were assessed by the AUC and compared using the DeLong test. A Kruskal-Wallis test was used to examine if the 34 GRFs differed between difficult- and easy-to-interpret NCs, and if difficulty level based on the traditional breast density (BD) categories differed among 115 low-BD and 124 high-BD NCs. The CC+MLO model achieved higher performance (0.71 AUC) than the individual CC and MLO model alone (0.66 each), but statistically non-significant difference was found (all p>0.05). Six GRFs were identified to be valuable in describing difficult-to-interpret NCs. 20 features, when compared between difficult- and easy-to-interpret NCs, differed significantly (p<0.05). No statistically significant difference was observed in difficulty between low- and high-BD NCs (p=0.709). GRF mammographic analysis can predict difficult-to-interpret NCs.