Integrated Intratumoral and peritumoral APTw and ADC assessment for preoperative glioma grading: A multicenter study.

PURPOSE: To investigate the value of integrated intratumoral and peritumoral amide proton transfer-weighted (APTw) imaging and apparent diffusion coefficient (ADC) assessment for preoperative glioma grading in a multicenter setting.

METHODS

This prospective multicenter study screened 886 consecutive adults with suspected diffuse glioma from three centers between October 2022 and December 2025. After applying the eligibility criteria, 566 patients with histopathologically confirmed adult diffuse glioma were included. Mean APTw (mAPTw) and mean ADC (mADC) values were measured in the tumor core, proximal peritumoral brain zone (PBZ), and distal PBZ. Three logistic regression models were developed: an intratumoral model, a peritumoral model, and an integrated intratumoral-peritumoral model. Diagnostic performance was evaluated using receiver operating characteristic analysis, DeLong tests, calibration analysis, and decision curve analysis.

RESULTS

A total of 272 low-grade gliomas (LGGs) and 294 high-grade gliomas (HGGs) were included. Across all three centers, HGGs showed significantly higher intratumoral mAPTw and lower intratumoral mADC than LGGs. Similar differences were observed in the proximal PBZ, with higher mAPTw and lower mADC in HGGs than in LGGs, whereas distal PBZ mAPTw and mADC showed no significant group differences. Among single parameters, intratumoral mAPTw and intratumoral mADC showed better diagnostic performance than proximal PBZ parameters. The integrated model achieved the highest diagnostic performance, with AUCs of 0.910 (95% CI, 0.869-0.951), 0.863 (95% CI, 0.809-0.916), and 0.849 (95% CI, 0.791-0.906) in Centers 1, 2, and 3, respectively. DeLong tests showed that the integrated model significantly outperformed both the intratumoral and peritumoral models in all three centers. Calibration analysis demonstrated good agreement between predicted and observed probabilities, and decision curve analysis showed greater net benefit for the integrated model across most clinically relevant threshold probabilities.

CONCLUSION

Integrated intratumoral and proximal peritumoral APTw-ADC assessment may provide a useful noninvasive approach for preoperative glioma grading across multiple centers.