MRI and lumbar puncture may not be necessary for diagnosing and managing CAR-T therapy-related ICANS in all patients because they rarely change treatment, a study suggests.
Conversely, the researchers from the University Hospital of Rennes, France, said EEG had a greater therapeutic impact and should be considered a necessary diagnostic intervention.
The findings raise questions about international guidelines recommending performing MRI, lumbar puncture (LP), and electroencephalogram (EEG) on patients, based on symptom severity, before starting treatment.
The study published in Blood Advances (link here) analysed data from 190 patients (62% male, average age 64) with CAR T-cells, most of whom (73%) were receiving treatment for refractory/relapsed diffuse large B cell lymphoma (DLBCL).
Just under half of the studied cohort (48%) developed ICANS, and their subsequent treatment was determined by their unique presentation and physician recommendation per current guidelines.
Most (80%) had at least one diagnostic intervention, MRI, LP or EEG, while a third (34%) had all three.
The analysis revealed that of the 78% of patients who underwent MRI, most scans (80%) were considered normal and that treatment was adjusted for just 4% of those with abnormal results.
Just under half of ICANS patients (47%) had lumbar puncture, but active infections were not identified in any cases, although 7% received pre-emptive antimicrobials on continued suspicion of infection.
Just over half (56%) received an EEG, and only 18% showed normal results. Brain dysfunction was evident in 45% of patients. Following the EEG, 16% of patients revised their treatment plans based on the findings.
“Notably, 6 EEG (12%) reported seizure or status epilepticus [and] there were two patients with ICANS grade 2 and 3 (6% of EEG respectively) and 4 (33%) patients with ICANS grade 4 who developed seizure or status epilepticus on their EEG despite the absence of clinical symptoms of epilepsy,” according to the paper.
The study had limitations, including a need for more standardisation for MRI and EEG assessments and the small number of patients in the study cohort.
However, the findings show “that diagnostic investigations recommended by international guidelines for ICANS management rarely result in therapeutic changes for MRI (4%) and LP (7%, all 382 irrelevant), questioning the need for systematic assessment,” the authors said.
“On the other hand, EEG should still be performed in patients with ICANS grade 2+ considering its significant therapeutic impact”.
The results “highlight the need for novel ICANS management guidelines, which will limit the use of investigations to situations with a significant therapeutic impact and with an optimal risk-benefit ratio,” they stressed.