Personalized radiomics signature to screen for KIT-11 mutation genotypes among patients with gastrointestinal stromal tumors: a retrospective multicenter study.

OBJECTIVES: Gastrointestinal stromal tumors (GISTs) carrying different KIT exon 11 (KIT-11) mutations exhibit varying prognoses and responses to Imatinib. Herein, we aimed to determine whether computed tomography (CT) radiomics can accurately stratify KIT-11 mutation genotypes to benefit Imatinib therapy and GISTs monitoring. METHODS: Overall, 1143 GISTs from 3 independent centers were separated into a training cohort (TC) or validation cohort (VC). In addition, the KIT-11 mutation genotype was classified into 4 categories: no KIT-11 mutation (K11-NM), point mutations or duplications (K11-PM/D), KIT-11 557/558 deletions (K11-557/558D), and KIT-11 deletion without codons 557/558 involvement (K11-D). Subsequently, radiomic signatures (RS) were generated based on the arterial phase of contrast CT, which were then developed as KIT-11 mutation predictors using 1408 quantitative image features and LASSO regression analysis, with further evaluation of its predictive capability. RESULTS: The TC AUCs for K11-NM, K11-PM/D, K11-557/558D, and K11-D ranged from 0.848 (95% CI 0.812-0.884), 0.759 (95% CI 0.722-0.797), 0.956 (95% CI 0.938-0.974), and 0.876 (95% CI 0.844-0.908), whereas the VC AUCs ranged from 0.723 (95% CI 0.660-0.786), 0.688 (95% CI 0.643-0.732), 0.870 (95% CI 0.824-0.918), and 0.830 (95% CI 0.780-0.878). Macro-weighted AUCs for the KIT-11 mutant genotype ranged from 0.838 (95% CI 0.820-0.855) in the TC to 0.758 (95% CI 0.758-0.784) in VC. TC had an overall accuracy of 0.694 (95%CI 0.660-0.729) for RS-based predictions of the KIT-11 mutant genotype, whereas VC had an accuracy of 0.637 (95%CI 0.595-0.679). CONCLUSIONS: CT radiomics signature exhibited good predictive performance in estimating the KIT-11 mutation genotype, especially in prediction of K11-557/558D genotype. RS-based classification of K11-NM, K11-557/558D, and K11-D patients may be an indication for choice of Imatinib therapy.

Objective assessment of transcatheter arterial chemoembolization angiographic endpoints: preliminary study of quantitative digital subtraction angiography.

PURPOSE: To explore the significance of quantitative digital subtraction angiography (DSA; Q-DSA) in the assessment of chemoembolization endpoints. MATERIALS AND METHODS: Twenty patients with hepatocellular carcinoma treated with chemoembolization were included in the study. All DSA series before and after chemoembolization were postprocessed with Q-DSA. The maximal enhancement and time to peak (TTP) were measured for several homologous anatomic landmarks, including the origin and embolized site of the tumor-feeding artery, parenchyma of the tumor, and ostia of the pre- and postprocedure catheter. The TTP, tumor blood supply time, and maximal enhancement of the time density curve (TDC) were analyzed. RESULTS: Of the 20 DSA series collected, 18 were successfully postprocessed. The TTPs of the landmarks before and after treatment were 3.60 seconds±1.02 and 3.57 seconds±0.78 at the ostia of the catheter, 3.91 seconds±1.01 and 4.09 seconds±1.14 at the origin site of the tumor-feeding artery, and 4.07 seconds±1.02 and 5.60 seconds±1.56 s the embolized site of the main tumor-feeding artery, respectively. Statistical differences were detected between pre- and postprocedural TTP of the embolized site of the feeding artery (P<.01), as well as between pre- and postprocedural tumor blood supply time (P<.01). The mean maximal TDC enhancements of selected tumor spots were 3.01 units±1.04 and 0.81 units±0.35 before and after the procedure (P<.01), respectively. CONCLUSIONS: Q-DSA may provide a feasible quantitative measurement in the assessment of chemoembolization endpoints.