Computed tomography radiogenomics: A potential tool for prediction of molecular subtypes in gastric stromal tumor

Preoperative knowledge of mutational status of gastrointestinal stromal tumors (GISTs) is essential to guide the individualized precision therapy.

To develop a combined model that integrates clinical and contrast-enhanced computed tomography (CE-CT) features to predict gastric GISTs with specific genetic mutations, namely KIT exon 11 mutations or KIT exon 11 codons 557-558 deletions.

A total of 231 GIST patients with definitive genetic phenotypes were divided into a training dataset and a validation dataset in a 7:3 ratio. The models were constructed using selected clinical features, conventional CT features, and radiomics features extracted from abdominal CE-CT images. Three models were developed: Model_{CT sign}, model_{CT sign + rad}, and model CT_{sign + rad + clinic}. The diagnostic performance of these models was evaluated using receiver operating characteristic (ROC) curve analysis and the Delong test.

The ROC analyses revealed that in the training cohort, the area under the curve (AUC) values for model_{CT sign}, model_{CT sign + rad}, and model_{CT sign + rad + clinic} for predicting KIT exon 11 mutation were 0.743, 0.818, and 0.915, respectively. In the validation cohort, the AUC values for the same models were 0.670, 0.781, and 0.811, respectively. For predicting KIT exon 11 codons 557-558 deletions, the AUC values in the training cohort were 0.667, 0.842, and 0.720 for model_{CT sign}, model_{CT sign + rad}, and model_{CT sign + rad + clinic}, respectively. In the validation cohort, the AUC values for the same models were 0.610, 0.782, and 0.795, respectively. Based on the decision curve analysis, it was determined that the model_{CT sign + rad + clinic} had clinical significance and utility.

Our findings demonstrate that the combined model_{CT sign + rad + clinic} effectively distinguishes GISTs with KIT exon 11 mutation and KIT exon 11 codons 557-558 deletions. This combined model has the potential to be valuable in assessing the genotype of GISTs.