Multimodel habitats constructed by perfusion and/or diffusion MRI predict isocitrate dehydrogenase mutation status and prognosis in high-grade gliomas

AIM

To determine whether tumour vascular and cellular heterogeneity of high-grade glioma (HGG) is predictive of isocitrate dehydrogenase (IDH) mutation status and overall survival (OS) by using tumour habitat-based analysis constructed by perfusion and/or diffusion magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Seventy-eight HGG patients that met the 2021 World Health Organization WHO Classification of Tumors of the Central Nervous System, 5th edition (WHO CNS5), were enrolled to predict IDH mutation status, of which 32 grade 4 patients with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) promoter were enrolled for prognostic analysis. The deep-learning-based model nnU-Net and K-means clustering algorithm were applied to construct the Traditional Habitat, Vascular Habitat (VH), Cellular Density Habitat (DH), and their Combined Habitat (CH). Quantitative parameters were extracted and compared between IDH-mutant and IDH-wild-type patients, respectively, and the prediction potential was evaluated by receiver operating characteristic (ROC) curve analysis. OS was analysed using Kaplan-Meier survival analysis and the log-rank test.

RESULTS

Compared with IDH-mutants, median relative cerebral blood volume (rCBVmedian) values in the whole enhancing tumour (WET), VH1, VH3, CH1-4 habitats were significantly increased in IDH-wild-type HGGs (all p<0.05). Additionally, the accuracy of rCBVmedian values in CH1 outperformed other habitats in identifying IDH mutation status (p<0.001) at a cut-off value of 4.83 with AUC of 0.815. Kaplan-Meier survival analysis highlighted significant differences in OS between the populations dichotomised by the median of rCBVmedian in WET, VH1, CH1-3 habitats (all p<0.05).

CONCLUSIONS

The habitat imaging technique may improve the accuracy of predicting IDH mutation status and prognosis, and even provide a new direction for subsequent personalised precision treatment.

Self-assembling peptide nanofiber as potential substrates in islet transplantation

Hypoxia and reoxygenation (H/R)-induced damage often happens soon after islets are transplantation. The process of islet isolation and purification causes the rapid onset of hypoxia. We sought to develop a functional scaffold to sustain the structure and function of islets as well as to recover some of the surface molecules damaged during isolation, seeking to improve islet transplantation outcomes. Self-assembling peptide nanofiber (SAPNF), a new type of substrate has been shown to be an excellent biological material for neuronal cell culture and tissue engineering in animals. In this study, we investigated the protective effect of SAPNF on damage to rat islets. Freshly prepared rat islets from male Sprague-Dawley rats were seeded in plates coated with (SAPNF-treated group) or without (control group) SAPNF. The islets were then divided into two groups culture under normoxia for 7 days versus exposure to hypoxia (< 1% O2) for 6 hours followed by reoxygenation for 24 hours. The results showed that SAPNF exhibited improving effects on viability and function of cultured islets, protecting the one from H/R-induced damage. In both groups, the stimulation index of SAPNF-treated groups were about two times the controls. SAPNF treatment decreased apoptotic rates of islet cells. These results suggested the usefulness of SAPNF to maintain the viability and function of rat pancreatic islets. SAPNF may be a potential scaffold for clinical islet transplantation.