Validating Brain Tumor Reporting and Data System (BT-RADS) as a Diagnostic Tool for Glioma Follow-Up after Surgery

Abstract

Gliomas are a type of brain tumor that requires accurate monitoring for progression following surgery. The Brain Tumor Reporting and Data System (BT-RADS) has emerged as a potential tool for improving diagnostic accuracy and reducing the need for repeated operations. This prospective multicenter study aimed to evaluate the diagnostic accuracy and reliability of BT-RADS in predicting tumor progression (TP) in postoperative glioma patients and evaluate its acceptance in clinical practice. The study enrolled patients with a history of partial or complete resection of high-grade glioma. All patients underwent two consecutive follow-up brain MRI examinations. Five neuroradiologists independently evaluated the MRI examinations using the BT-RADS. The diagnostic accuracy of the BT-RADS for predicting TP was calculated using histopathology after reoperation and clinical and imaging follow-up as reference standards. Reliability based on inter-reader agreement (IRA) was assessed using kappa statistics. Reader acceptance was evaluated using a short survey. The final analysis included 73 patients (male, 67.1%; female, 32.9%; mean age, 43.2 ± 12.9 years; age range, 31-67 years); 47.9% showed TP, and 52.1% showed no TP. According to readers, TP was observed in 25-41.7% of BT-3a, 61.5-88.9% of BT-3b, 75-90.9% of BT-3c, and 91.7-100% of BT-RADS-4. Considering >BT-RADS-3a as a cutoff value for TP, the sensitivity, specificity, and accuracy of the BT-RADS were 68.6-85.7%, 84.2-92.1%, and 78.1-86.3%, respectively, according to the reader. The overall IRA was good (κ = 0.75) for the final BT-RADS classification and very good for detecting new lesions (κ = 0.89). The readers completely agreed with the statement "the application of the BT-RADS should be encouraged" (score = 25). The BT-RADS has good diagnostic accuracy and reliability for predicting TP in postoperative glioma patients. However, BT-RADS 3 needs further improvements to increase its diagnostic accuracy.

Keywords: BT-RADS; follow-up; glioma; magnetic resonance imaging; tumor progression.

Figure 1

Flowchart of the study.

Figure 2

A 67-year-old male patient underwent total resection of pathologically proven HGG. The patient did not receive any antiangiogenic treatment. (a,b) MRI was performed 2 months after the operation while the patient was undergoing radiotherapy. (a) Axial FLAIR shows a CSF-like signal intensity resection cavity (arrow). (b) The axial postcontrast T1WI shows a mild peripheral enhancement of the cavity (arrow). (c,d) A follow-up MRI was performed 45 days after the completion of radiotherapy; the patient was clinically stable. (c) The axial FLAIR image shows an increased signal at the periphery of the resection cavity (arrow). (d) The axial post-contrast T1WI shows patchy central enhancement with less peripheral enhancement (arrow). The patient was categorized as BT-RADS-3a. (e,f) A follow-up MRI was performed 6.5 months after the completion of radiotherapy; the patient was clinically deteriorating. (e) The axial FLAIR shows a new intermediate signal-intensity lesion (arrow) with surrounding edema and mass effect. (f) The axial post-contrast T1WI image shows heterogeneous enhancement of the lesion (arrow). The multidisciplinary brain tumor team considered tumor progression, the patient underwent reoperation, and histopathology showed recurrence.

Figure 3

A 31-year-old male patient underwent total resection of HGG. The patient did not receive antiangiogenic therapy. (a,b) MRI was performed 9 months after completion of radiotherapy. (a) Axial FLAIR image shows right frontal high-signal intensity gliosis at the operative bed (arrow) with a negative mass effect on the ipsilateral ventricular system. (b) The axial post-contrast T1WI image shows no enhancement (arrow). (c,d) A follow-up MRI was performed 15 months after the completion of radiotherapy; the patient was clinically stable. (c) The axial FLAIR image shows stable high-signal intensity gliosis (arrow) with decreased negative mass effect on the ventricular system. (d) The axial post-contrast T1WI image shows small, enhanced foci (arrow). The patient was categorized as BT-RADS-3b. (e,f) A follow-up MRI was performed 22 months after the completion of radiotherapy; the patient was clinically deteriorating. (e) The axial FLAIR image shows a new intermediate signal intensity lesion (arrow) with a positive mass effect on the ipsilateral ventricular system. (f) The axial post-contrast T1WI image shows heterogeneous marginal enhancement of the lesion (arrow). The multidisciplinary brain tumor team considered tumor progression, the patient underwent reoperation, and histopathology showed recurrence.

Figure 4

A 50-year-old male patient underwent total resection of HGG. The patient did not receive antiangiogenic therapy. (a,b) MRI was performed 4 months after the completion of radiotherapy. (a) The axial FLAIR image shows a right frontal high signal intensity area at the operative bed (arrow) extending to the genu of the corpus callosum to the opposite side with a mild positive mass effect on the related cortical sulci. (b) The axial post-contrast T1WI image shows no enhancement (arrow). (c,d) A follow-up MRI was performed 8 months after the completion of radiotherapy; the patient was clinically stable. (c) The axial FLAIR image shows a stable FLAIR component and mass effect (arrow). (d) The axial post-contrast T1WI image shows a stable enhancement pattern (arrow). The patient was categorized as BT-RADS-2. (e,f) A follow-up MRI was performed 12 months after the completion of radiotherapy; the patient was clinically stable. (e) The axial FLAIR image shows a stable FLAIR component and no mass effect (arrow). (f) The axial post-contrast T1WI image shows a stable enhancement pattern (arrow). The multidisciplinary brain tumor team considered the lesion to be non-progressive.