Using of amide proton transfer-weighted images in the staging of diffuse gliomas: a prospective study

Introduction: Diffuse gliomas are the most common brain tumors. Gliomas of high malignancy are characterized by a poor prognosis and require complex combined treatment. Amide proton transfer is a modern technique that makes it possible to visualize metabolic changes in a tumor and increase the effectiveness of an MRI scan.

Objective: to evaluate the possibilities of amide proton transfer in determining the degree of malignancy of diffuse cerebral gliomas.

Materials and Methods: The study included 73 patients with histologically confirmed supratentorial adult type diffuse gliomas of the who underwent surgical treatment at the University clinic of PIMU from 2023 to 2025. The study was performed on a Philips Ingenia Elite X 3T magnetic resonance imaging machine (the Netherlands). The study protocol consisted of a standard protocol and amide proton transfer-weighted images (APT-WI). The average, minimum and maximum values of the relative concentration of mobile amide groups in the central and peripheral parts of the tumor, absolute and normalized by unchanged white matter, were calculated. The Mann-Whitney test was used to determine differences between patient groups.

Results: The absolute values of the relative concentration of free amide groups in the central part of the tumor were higher in comparison with gliomas of low malignancy: average — 2.68 [2.07; 3.30] and 1.44 [1.34; 1.92], maximum — 2.96 [2.37; 3.81] and 1.62 [1.49; 2.11], minimum — 2.34 [1.62; 2.86] and 1.25 [1.14; 1.47], p<0.05. Similar differences were also found in the perifocal area.— 1,58 [1,28; 1,90], 2,29 [1,85; 2,77], 0,95 [0,61; 1,16] — the average, maximum and minimum values, respectively, in diffuse gliomas of high malignancy and 1,02 [0,83; 1,11], 1,57 [1,21; 1.67], 0.61 [0.36; 0.79] in low-grade gliomas, p><0.05. The normalized values differed only in the central part of the tumor: 3,25 [2,32; 4,86], 5,58 [3,50; 16,42] — the average and maximum values in tumors with a high degree of malignancy and 2,19 [1,68; 3,60], 3,10 [2,36; 12,19] in low grade tumors, respectively, p><0.05. When comparing Grades 2.3 and 4 separately, a tendency was revealed to increase the values of the image signal weighted by amide proton transfer from Grade 2 to Grade 4, both in the central part of the tumor and in the peripheral. DISCUSSIONS: Determining the degree of malignancy of a particular tumor in the preoperative period is one of the key tasks of radiology, as it allows for adequate treatment planning, improving living standards and increasing survival. The results of the study demonstrate the possibilities of amide proton transfer in the staging of glial tumors. The relative concentration of free amide groups, determined based on the signal intensity of APT-weighted images, increases accordingly to an increase in the degree of malignancy, which is probably due to a number of histological and metabolic differences in gliomas of different grades. CONCLUSION: Statistically significant differences were found between the values of the relative concentration of free amide groups in the central and perifocal regions of glial tumors with different grades. The amide proton transfer method is informative in the study of patients with diffuse cerebral gliomas. KEYWORDS: magnetic resonance imaging, amide proton transfer; neuroimaging; gliomas; degree of malignancy > < 0.05. Similar differences were also found in the perifocal area.— 1,58 [1,28; 1,90], 2,29 [1,85; 2,77], 0,95 [0,61; 1,16] — the average, maximum and minimum values, respectively, in diffuse gliomas of high malignancy and 1,02 [0,83; 1,11], 1,57 [1,21; 1.67], 0.61 [0.36; 0.79] in low-grade gliomas, p < 0.05. The normalized values differed only in the central part of the tumor: 3,25 [2,32; 4,86], 5,58 [3,50; 16,42] — the average and maximum values in tumors with a high degree of malignancy and 2,19 [1,68; 3,60], 3,10 [2,36; 12,19] in low grade tumors, respectively, p < 0.05. When comparing Grades 2.3 and 4 separately, a tendency was revealed to increase the values of the image signal weighted by amide proton transfer from Grade 2 to Grade 4, both in the central part of the tumor and in the peripheral.

Discussion: Determining the degree of malignancy of a particular tumor in the preoperative period is one of the key tasks of radiology, as it allows for adequate treatment planning, improving living standards and increasing survival. The results of the study demonstrate the possibilities of amide proton transfer in the staging of glial tumors. The relative concentration of free amide groups, determined based on the signal intensity of APT-weighted images, increases accordingly to an increase in the degree of malignancy, which is probably due to a number of histological and metabolic differences in gliomas of different grades.

Conclusion: Statistically significant differences were found between the values of the relative concentration of free amide groups in the central and perifocal regions of glial tumors with different grades. The amide proton transfer method is informative in the study of patients with diffuse cerebral gliomas.

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