Table 1.

Interpretation of MRI findings related to type and time of treatment

MRI date (months postdiagnosis)	Vinblastinea status	Dabrafenib/trametinib statusb	Tumor mass dimensions (cm)			Radiologist interpretation/notes	Reason for MRI
			SI	TRV	AP
A
Initial diagnosis	Prior	Prior	1.7	1.5	1.5	No significant contrast enhancement associated with this lesion, and no abnormal contrast enhancement appreciated in the remainder of the brain	Sudden onset nystagmus and loss of vision in left eye
46 mo	Prior	Prior	2.0	2.5	2.6	T2 prolongation mass lesion centered within the midbrain; increased in size since the previous study	Preoperative evaluation prior to initial biopsy and tumor resection
47 mo	Prior	Prior	2.1	2.9	2.8	Mass lesion minimally increased in size compared to previous imaging; central portion of the lesion shows increased T2 signal compared to the peripheral portion and enhances diffusely with contrast	Routine surveillance
50 mo	Prior	Prior	2.1	2.6	2.7	Mass unchanged to slightly decreased in size when compared to previous imaging	Evaluation prior to commencing chemotherapy
52 mo	Prior	Prior	1.8	2.5	2.8	Expansile, T2 prolongation mass lesion with slight decrease in size; central area of the mass shows increased T2 signal and contrast enhancement	Routine surveillance
B
57 mo	Active (3 mo)	Prior	1.7	2.6	2.7	Complex appearing mass within the midbrain, with measurements comparable to prior imaging	Disease assessment/postchemotherapy commencement
60 mo	Active (6 mo)	Prior	2.0	2.8	2.6	Increased size of mass compared to most recent imaging.	Routine surveillance
63 mo	Active (9 mo)	Prior	2.6	3.2	2.8	Increased size of both the solid and cystic components of the midbrain mass compared to previous MRI	Routine surveillance
64 mo	Stopped	Prior	2.9	3.5	2.8	Slight further increase in size of the cystic portion of the mixed solid and cystic mass; enhancing solid component appears unchanged	Routine surveillance
65 mo	Stopped	Prior	NA	NA	NA	Almost complete resection of the enhancing tissue in the central lesion; residual crescent of T2 signal abnormality is still concerning for nonenhancing tumor	Intraoperative during tumor resection
68 mo	Stopped	Prior	1.7	2.3	2.4	New avidly enhancing nodules along the anterior aspect of the mass, suggestive of tumor progression.	Routine surveillance
C
71 mo	Stopped	Active (2 mo)	1.6	2.2	2.3	Similar in size with decreased enhancement	Routine surveillance
74 mo	Stopped	Active (5 mo)	1.5	2.2	2.2	Stable appearance of residual tumor	Routine surveillance
78 mo	Stopped	Active (9 mo)	1.4	2.0	2.2	No evidence of tumor progression	Routine surveillance
81 mo	Stopped	Active (12 mo)	1.4	2.0	2.2	Essentially unchanged in imaging appearance and tumor dimensions	Routine surveillance
84 mo	Stopped	Active (15 mo)	1.4	2.0	2.0	Stable nonenhancing, lobulated midbrain mass; unchanged mild to moderate enlargement of the lateral and third ventricles	Routine surveillance

“Prior” refers to the time period before therapy initiation. (MRI) Magnetic resonance imaging, (SI) superior to inferior, (TRV) transverse, (AP) anteroposterior.

^aVinblastine dosage, 6 mg/m²/dose intravenously every 2 wk.

^bDabrafenib dosage, 150 mg twice a day; trametinib dosage, 1.5 mg twice a day.