Table 1.

Criteria for assessment of response^*

Category	Criteria
Complete response (CR)	Disappearance of all enhancing or nonenhancing tumor on consecutive contrast-enhanced MRI scans at least one month apart and neurologically stable or improved
Partial response (PR)	At least 50% reduction in the size of enhancing or nonenhancing tumor maintained for at least one month and neurologically stable or improved
Minimal response (MR)	25%–49% reduction in size of enhancing or nonenhancing tumor maintained for at least one month and neurologically stable or improved
Stable disease (SD)	Any changes in enhancing or nonenhancing tumor size that do not qualify for CR, PR, MR, or PD classification
Progressive disease (PD)	At least 25% increase in size of enhancing or nonenhancing tumor or any new tumor on MRI scan, or neurologically worse
For patients with OPG, one of the following was also applicable for assessment of PD:	Progressive visual loss, i.e., deterioration of visual acuity > 1 octave, or decline in vision to 20/400, or increase in papilledema, or increase in diameter of optic nerve of ≥ 2 mm, and/or increase in the distribution of tumor involving the optic tract or optic radiations as evidenced by MRI scan of brain (T1-weighted imaging with and without contrast and T2- weighted imaging)

Abbreviation: OPG, optic pathway glioma.

^*Comparisons of objective assessments, excluding progressive disease, were based upon changes in tumor size on the gadolinium-enhanced MRI scan of brain compared with the baseline scan. Tumor size was measured as the product of the largest perpendicular diameters. Determination of progressive disease was based upon comparison with the previous scan with the smallest measurements.