RT Journal Article SR Electronic T1 Comparison of Volumetric and 2D Measurements and Longitudinal Trajectories in the Response Assessment of BRAF V600E-Mutant Pediatric Gliomas in the Pacific Pediatric Neuro-Oncology Consortium Clinical Trial JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 475 OP 482 DO 10.3174/ajnr.A8189 VO 45 IS 4 A1 Ramakrishnan, Divya A1 Brüningk, Sarah C. A1 von Reppert, Marc A1 Memon, Fatima A1 Maleki, Nazanin A1 Aneja, Sanjay A1 Kazerooni, Anahita Fathi A1 Nabavizadeh, Ali A1 Lin, MingDe A1 Bousabarah, Khaled A1 Molinaro, Annette A1 Nicolaides, Theodore A1 Prados, Michael A1 Mueller, Sabine A1 Aboian, Mariam S. YR 2024 UL http://www.ajnr.org/content/45/4/475.abstract AB BACKGROUND AND PURPOSE: Response on imaging is widely used to evaluate treatment efficacy in clinical trials of pediatric gliomas. While conventional criteria rely on 2D measurements, volumetric analysis may provide a more comprehensive response assessment. There is sparse research on the role of volumetrics in pediatric gliomas. Our purpose was to compare 2D and volumetric analysis with the assessment of neuroradiologists using the Brain Tumor Reporting and Data System (BT-RADS) in BRAF V600E-mutant pediatric gliomas.MATERIALS AND METHODS: Manual volumetric segmentations of whole and solid tumors were compared with 2D measurements in 31 participants (292 follow-up studies) in the Pacific Pediatric Neuro-Oncology Consortium 002 trial (NCT01748149). Two neuroradiologists evaluated responses using BT-RADS. Receiver operating characteristic analysis compared classification performance of 2D and volumetrics for partial response. Agreement between volumetric and 2D mathematically modeled longitudinal trajectories for 25 participants was determined using the model-estimated time to best response.RESULTS: Of 31 participants, 20 had partial responses according to BT-RADS criteria. Receiver operating characteristic curves for the classification of partial responders at the time of first detection (median = 2 months) yielded an area under the curve of 0.84 (95% CI, 0.69–0.99) for 2D area, 0.91 (95% CI, 0.80–1.00) for whole-volume, and 0.92 (95% CI, 0.82–1.00) for solid volume change. There was no significant difference in the area under the curve between 2D and solid (P = .34) or whole volume (P = .39). There was no significant correlation in model-estimated time to best response (ρ = 0.39, P >.05) between 2D and whole-volume trajectories. Eight of the 25 participants had a difference of ≥90 days in transition from partial response to stable disease between their 2D and whole-volume modeled trajectories.CONCLUSIONS: Although there was no overall difference between volumetrics and 2D in classifying partial response assessment using BT-RADS, further prospective studies will be critical to elucidate how the observed differences in tumor 2D and volumetric trajectories affect clinical decision-making and outcomes in some individuals.AUCarea under the curveBT-RADSBrain Tumor Reporting and Data SystemMinRminor responsenRMSEnormalized root mean squared errorPDprogressive diseasePNOCPacific Pediatric Neuro-Oncology ConsortiumPRpartial responseRAPNOResponse Assessment in Pediatric Neuro-OncologyROCreceiver operating characteristicSDstable disease