Influence of key histological characteristics on 18F-fluorodeoxyglucose /18F-choline positron emission tomography positivity in hepatocellular carcinoma: A machine learning study

Abstract

PurposeTo determine the characteristics influence of key histological on 18F-fluorodeoxyglucose (18F-FDG) and 18F-choline positron emission tomography (PET) positivity in hepatocellular carcinoma (HCC).Materials and methodsThe 18F-FDG/18F-choline PET imaging findings of 103 histologically proven HCCs (from 62 patients, of which 47 underwent hepatectomy and 15 received liver transplantation) were retrospectively examined to assess the following key histological parameters: Grade, capsule, microvascular invasion (mVI), macrovascular invasion (MVI), and necrosis. Using a ratio of 70/30 for training and testing sets, respectively, a penalized classification model (Elastic Net) was trained using 100 repeated cross-validation procedures (10-fold cross-validation for hyperparameter optimization). The contribution of each histological parameter to the PET positivity was determined using the Shapley Additive Explanations method. Receiver operating characteristic curves with and without dimensionality reduction were finally estimated and compared.ResultsAmong the five key histological characteristics of HCC (Grade, capsule, mVI, MVI, and necrosis), mVI and tumor Grade (I–III) showed the highest relevance and robustness in explaining HCC uptake of 18F-FDG and 18F-choline. MVI and necrosis status both showed high instability in outcome predictions. Tumor capsule had a minimal influence on the model predictions. On retaining only mVI and Grades I–III for the final analysis, the area under the receiver operating characteristic (ROC) curve values were maintained (0.68 vs. 0.63, 0.65 vs. 0.64, and 0.65 vs. 0.64 for 18F-FDG, 18F-choline, and their combination, respectively).Conclusion18F-FDG/18F-choline PET positivity appears driven by both the Grade and mVI components in HCC. Consideration of the tumor microenvironment will likely be necessary to improve our understanding of multitracer PET positivity.

Conversion therapy for advanced hepatocellular carcinoma in the era of precision medicine: Current status, challenges and opportunities

“…Therefore, a critical issue has gradually been raised regarding how to preoperatively assess the extent of necrosis in the lesions after conversion therapy, which is expected to provide first‐line evidence for surgical decision‐making. Although numerous studies are currently underway to establish different models for predicting the degree of lesion necrosis through methods including novel serum biomarkers, liquid biopsy techniques, radiomics, and AI training, 68 , 69 , 70 , 71 , 72 , 73 the predictive efficacy remains unsatisfactory. Thus, there is an urgent need for further exploration of advanced imaging techniques and novel, promising serum biomarkers to achieve more accurate and precise prediction of tumor necrosis before conversion resection.…”