Differentiating between PCNSL GCB Subtype and Non-GCB Subtype using Radiomics: A Multicenter Study

Abstract

Objectives To investigate the characteristics and pathological basis of MRI in germinal center B cell (GCB) and non-germinal center B cell (non-GCB) in PCNSL (primary central nervous system lymphoma). And to explore the predictive ability of MRI radiomics-based in differentiating the GCB and non-GCB of PCNSL. Methods This study retrospectively analyzed standard diagnostic MRI examinations in 24 immunocompetent patients (9 men; age 56.4 ± 15.1 years) with GCB and 56 immunocompetent patients (35 men; age 61.1 ± 9.3 years) with non-GCB. The radiomics features were extracted from ADC, DWI, and T1-CE images respectively, and the features were screened by machine learning algorithm and statistical method. Finally, radiomics models of seven different sequence permutations were constructed. The area under the receiver operating characteristic (ROC AUC) curve was used to evaluate the predictive performance of all models. Delong test was utilized to compare the differences among models. Results The GCB cases all showed diffusion restriction, which was observed in 80.36% of the non-GBM cases; p < 0.05. Grade 3 edema was rare in GCB cases (8.33%) and common in non-GCB cases (50.00%); p < 0.001. 62.50% of male patients were non-GCB and 37.50% of female patients were non-GCB; p < 0.05. Additionally, patients with the GCB subtype are younger than those with the non-GCB subtype; p < 0.05. The best prediction model in our study used a combination of ADC, DWI, and T1-CE achieving the highest AUC of 0.854. And there was a significant difference between the best-combined model and some of the other models. Conclusion The GCB subtype is commonly seen in women, with mild peritumoral edema in most cases and diffusion restriction in all cases; however, the non-GCB subtype is commonly seen in men, with severe peritumoral edema in most cases. Additionally, the radiomics model developed by all sequences combined had good performance in discriminating between GCB and non-GCB.