Table 1.

Summary of the proposed RANO response criteria for meningiomas

Criterion	CR	PR	MR	SD	PD
Target lesions	None	≥50% decrease in area relative to baseline	≥25% and <50% decrease in area relative to baseline	<25% decrease relative to baseline but <25% increase in area relative to nadir	≥25% increase in area relative to nadir*
Nontarget lesions	None	Stable or improved	Stable or improved	Stable or improved	Unequivocal PD*
New lesion(s)**	None	None	None	None	Present*
Corticosteroids	None	Stable or decreased	Stable or decreased	Stable or decreased	NA+
Clinical status	Stable or improved	Stable or improved	Stable or improved	Stable or improved	Worse*
Requirement for response	All	All	All	All	Any+

NA, not applicable.

*Progression occurs when this criterion is met.

**New lesion = new lesion not present on prior scans and visible in at least 2 projections. If a new lesion is equivocal, for example because of its small size, continued therapy may be considered, and follow-up evaluation will clarify if it represents truly new disease. If repeat scans confirm there is definitely a new lesion, then progression should be declared using the date of the initial scan showing the new lesion. For immunotherapy-based approaches, new lesions alone do not define progression (see “Guidance in the case of new lesion(s) while on immunotherapy”).

⁺Increase in corticosteroids alone will not be taken into account in determining progression in the absence of persistent clinical deterioration.