Table 5.

Proposal for a revised LANO grid

Patient Identification	Reference Scan		Follow-Up		Response Assessment 8
Name or number:
Sex:
Date of birth:
Dates of MRI
Relevant history	n.a.		Treatment since reference scan 7:		n.a.
			Date of last lumbar puncture:
MRI findings	Present (1) or absent (0) or non- evaluable (NE) 5	Individual dimensions (N1, N2, N3: X x Y mm) of 3 largest measurable nodules (measurable defined as > 5 x 5 mm (orthogonal diameters in 2 planes)	Present (1) or absent (0) or non-evaluable (NE)	Individual dimensions (N1, N2, N3: X x Y mm) of 3 largest measurable nodules (measurable defined as > 5 x 5 mm (orthogonal diameters in 2 planes)	Change from previous MRI
Items related to assessment to leptomeningeal metastasis
Brain
Nodules (subarachnoid or ventricular)1					□ improved
					□ no change
					□ worse
Leptomeningeal linear enhancement2		n.a.6		n.a.	□ improved
					□ no change
					□ worse
Hydrocephalus3		n.a.		n.a.	□ improved
					□ no change
					□ worse
Spine
Nodules (subarachnoid)					□ improved
					□ no change
					□ worse
Leptomeningeal linear enhancement		n.a.		n.a.	□ improved
					□ no change
					□ worse
Overall response assessment for LM (CR, PR, SD, PD, or NE)
Items not related to assessment of leptomeningeal metastasis 4
Brain
Parenchymal (brain) metastases					□ CR9
					□ PR
					□ SD
					□ PD
Spine
Parenchymal (intramedullary) metastases					□ CR
					□ PR
					□ SD
					□ PD

Abbreviations: CR = complete response, PD = partial response, SD = stable disease, PD = progressive disease.

Explanations:

¹A nodule is a contrast-enhancing lesion that is defined as LM-related as opposed to parenchymal if there is direct contact (less than 2 mm distance) between the outer edge of the nodule and the leptomeninges on contrast-enhanced scans.

² Leptomeningeal linear enhancement may include cranial nerve or spinal nerve root, cerebellar folia, ventricular ependymal, or cerebral sulcal enhancement.

³ Hydrocephalus is assessed by determining the Evans index calculated on T1-weighted axial MR images. It represents the ratio of the largest diameter at the maximal width of the frontal horns relative to the largest internal diameter of the cranium on the same slide (Brix et al. Eur J Radiol 2017;95:28–32).

⁴These items shall be documented as present or absent, but are not used for LM response assessment.

⁵NE refers to scans that cannot be assessed for poor quality or incomplete sequences.

⁶Not applicable.

⁷ Therapeutic options for LM that should be noted here include any neurosurgical intervention, radiotherapy with information on the target of irradiation, systemic pharmacotherapy, and intrathecal pharmacotherapy. Assessing response treatment requires precise information on treatment delivered.

⁸ Progression is diagnosed if there is at least one new measurable nodule, if at least one measurable nodule that does not reach 10 mm in its two largest perpendicular diameters, increases in the product of the largest perpendicular diameters by 50% or more, if at least one nodule of at least 10 mm diameter in its perpendicular diameters increases in the product of the largest perpendicular diameters by 25% or more, or if the largest ventricular diameter increases by at least 25%. De novo linear leptomeningeal contrast enhancement alone also qualifies for progression unless attributable to lumbar puncture. Partial response requires regression of the size of all measurable nodules by 50% or more, without an increase in ventricular size. Complete response requires resolution of all contrast-enhancing, LM-related measurable lesions, without an increase in ventricular size. All other situations are considered stable disease. LM without measurable nodules can only remain stable as its best response. Linear enhancement cannot be quantified and is thus only noted as absent or present, but not used for response assessment unless developing de novo or affecting the leptomeninges in anatomic regions not previously affected—then this constitutes progressive disease. Deterioration in any one item qualifying for progression will be sufficient to call progression.

⁹According to RANO imaging criteria for brain metastasis (Lin et al. Lancet Oncology 2015;16:e270-8).

Technical considerations

MRI scans should be performed on the same scanner or at least a device of identical field strength during follow-up using the same imaging protocol at all timepoints during the follow-up, gadolinium-based contrast agent should be injected ideally 10 min, but not less than 5 min before acquisition of T1-weighted sequences and the slice thickness should be 1 mm or less in the brain and 3 mm or less for the spinal cord, as the leptomeningeal enhancement may have complex aspects and is commonly linear (Le Rhun et al. Ann Oncol 2017;28:iv84-iv99).

Since lumbar punctures may induce leptomeningeal enhancement, the date(s) of the last CSF analysis performed before MRI acquisition should appear on the grid.