Fig. 2. Confirmation of CPA tumor location and evaluation of tumor growth.

Mouse NF2^−/− Schwann cells are stereotactically injected into the CPA region of mice. a, During protocol development, MRI imaging was used to confirm tumor formation in the CPA region. T1-weighted images were obtained following intravenous administration of Magnevist (0.3 mmol/kg) via the tail vein, using the rapid acquisition relaxation-enhanced (RARE) sequence: TR (repetition time), 873 ms; TE (echo time), 17.8 ms; flip angle, 90°; 12 repetitions were acquired and averaged; acquisition time, 5 min 36 s; matrix size, 192 × 192; field of view, 2.5 × 2.5 cm; slice thickness, 0.5 cm; 16 sections were acquired and used²⁹. White arrow points to the CPA tumors. b, High-resolution ultrasound of the brain 12 d after tumor implantation in the CPA. White arrow points to wire mesh of tumors; rendering is from 3D data reconstruction using software from the Vevo770 In Vivo Imaging System and following the manufacturer’s instructions. c, During protocol development and optimization, concomitant measurement of blood GLuc activity and the tumor volume by ultrasound through a cerebellar window in mice bearing CPA NF2^−/− schwannoma showed linear correlation between the two measurements (N = 12). d, Representative H&E image of the brain section of a mouse bearing NF2^−/− schwannomas (white arrow) located in proximity to the cochlea (black arrow). Scale bars, 2 mm (a); 1 mm (d). Adapted with permission from Zhao, Y. et al. Targeting the cMET pathway augments radiation response without adverse effect on hearing in NF2 schwannoma models. Proc. Natl. Acad. Sci. USA 115, E2077–E2084 (2018). Institutional regulatory board permission for our experiments was obtained from the MGH IACUC.