Table 1.

International PCNSL Collaborative Group Consensus Guidelines for the Assessment of Response in PCNSL⁷

Response	Brain imaging	Steroid dose	Ophthalmologic examination	CSF cytology
Complete response	No contrast enhancing disease	None	Normal	Negative
Unconfirmed complete response	No contrast enhancing disease	Any	Normal	Negative
	Minimal enhancing disease	Any	Minor RPE abnormality	Negative
Partial response	50% decrease in enhancement	NA	Normal or minor RPE abnormality	Negative
	No contrast-enhancing disease	NA	Decrease in vitreous cells or retinal infiltrate	Persistent or suspicious
Progressive disease	25% increase in enhancing disease	NA	Recurrent or new disease	Recurrent or positive
	Any new site of disease
Stable disease	All scenarios not covered by responses above