Table 5.

Overall EANO–ESMO response assessment and guidance for LM treatment

Clinical	Cerebrospinal imaging	CSF cytology	Response determination	Action
Improved or stable	Improved	Improved or stable	Response	Continue treatment
Stable	Stable	Stable	Stable	Continue treatment
Worse	Improved or stable	Improved or stable	Suspicion of progression	Consider alternative neurological diagnoses or other reasons for clinical deterioration, change treatment only if there is no other explanation and if there is significant worsening of clinical signs for >2 weeks
Improved or stable	Improved or stable	Worse	Suspicion of progressiona or progression in case of de novo appearance of tumour cells in the CSFb	aContinue treatment with close follow-up (e.g. for 4 weeks) bChange treatment for de novo appearance of tumour cells from the same CSF site (lumbar or ventricular)
Worse	Improved or stable	Worse	Suspicion of progressiona or progression in case of de novo appearance of tumour cells in the CSFb	aConsider alternative neurological diagnoses; continue treatment with close follow-up (e.g. for 4 weeks) bChange treatment if there is worsening of clinical signs for >2 weeks or if there is appearance of tumour cells from the same CSF site (lumbar or ventricular)
Improved or stable	Worse	Improved or stable	Progression	Change treatment
Improved or stable	Worse	Worse	Progression	Change treatment
Worse	Worse	Improved or stable or worse	Progression	Change treatment

Adapted from Le Rhun et al.¹

In case of suspicion of clinical deterioration or uncertain imaging assessment, the response should be considered as stable. In these situations, a new assessment should be planned within a reasonably short time interval.

CSF, cerebrospinal fluid; EANO, European Association of Neuro-Oncology; ESMO, European Society for Medical Oncology; LM, leptomeningeal metastasis.