PET/MRI helpful in difficult cases of epilepsy: Study
France: Hybrid PET/MR can help in identifying brain lesions causing seizures in patients with drug-resistant epilepsy in cases of failure of standard approaches, reveals a recent study. The findings of the study, published in the journal Epilepsy Research, offer hope for patients for whom surgery is often the only treatment option as it allows to optimize the presurgical workup and increases the proportion of successful surgery even in the more complex cases.
Previous studies have shown hybrid PET/MR to be a promising tool in focal drug-resistant epilepsy, however, the additional value for the detection of epileptogenic lesions and surgical decision-making remains to be established.
For the study, Francine Chassoux, GHU Paris-Sainte-Anne, Paris, France, and colleagues retrospectively compared 18F-FDG PET/MR images with those obtained by a previous 18F-FDG PET co-registered with MRI (PET+MR) in 25 consecutive patients (16 females, 13-60 years) investigated for focal drug-resistant epilepsy.
Visual analysis was performed by two readers blinded from imaging modalities, asked to assess the technical characteristics (co-registration, quality of images), the confidence in results, the location of PET abnormalities and the presence of a structural lesion on MRI. Clinical impact on surgical strategy and outcome was assessed independently.
The study revealed the following findings:
- The location of epileptic focus was temporal in 9 patients and extra-temporal in 16 others. MRI was initially considered negative in 21 patients. PET stand-alone demonstrated metabolic abnormalities in 19 cases (76%), and the co-registration with MRI allowed the detection of 4 additional structural lesions.
- Compared to PET+MR, the PET/MR sensitivity was increased by 13% and new structural lesions (mainly focal cortical dysplasias) were detected in 6 patients (24%).
- Change of surgical decision-making was substantial for 10 patients (40%), consisting in avoiding invasive monitoring in 6 patients and modifying the planning in 4 others.
- Seizure-free outcome (follow-up>I year) was obtained in 12/14 patients who underwent a cortical resection.
"Hybrid PET/MR may improve the detection of epileptogenic lesions, allowing to optimize the presurgical work-up and to increase the proportion of successful surgery even in the more complex cases," wrote the study authors.
Reference:
Anthime Flaus, Charles Mellerio, Sebastian Rodrigo, Vincent Brulon, Vincent Lebon, Francine Chassoux. 18F-FDG PET/MR IN FOCAL EPILEPSY: A NEW STEP FOR IMPROVING THE DETECTION OF EPILEPTOGENIC LESIONS. Epilepsy Research, 2021, 106819, ISSN 0920-1211, https://doi.org/10.1016/j.eplepsyres.2021.106819.
