PET/MRI improves presurgical lesion detection in pediatric epilepsy

In children with difficult-to-diagnose epilepsy, PET/MRI can pinpoint areas of the brain responsible for seizures, even when MRI scans are negative or inconclusive. A new study of a large pediatric cohort, including children younger than 6, found that combining PET/MRI findings with EEG results and a structured presurgical evaluation improved the identification of seizure-causing brain tissue and informed treatment decisions. This research was published in the August issue of The Journal of Nuclear Medicine.

Children with underlying structural causes of epilepsy may benefit from early surgical intervention; however, these cases are often complex and difficult to diagnose. Recent studies show that PET/MRI, which images both the function and structure of the brain, can be valuable in detecting and localizing brain lesions that cause seizures.

“We know PET/MRI is a beneficial imaging tool for patients with epilepsy; however, the current scientific literature is limited because it mixes pediatric and adult subjects,” said Diego Cecchin, MD, director of the Unit of Nuclear Medicine and postgraduate School of Nuclear Medicine in the Department of Medicine at University-Hospital of Padova in Italy. “In our study, we sought to clarify the role of PET/MRI in the presurgical evaluation of pediatric epilepsy, including in very young children.”

The retrospective study included 79 patients 18 or younger who had a diagnosis of focal epilepsy, were under surgical evaluation and had a negative or inconclusive MRI result. Data were reviewed in several phases: (0) evaluation of previous MRI scans; masked review of PET/MRI-acquired MR images only; joint assessment of PET and MRI data by nuclear medicine and neuroradiology physicians; and verification of PET/MRI findings compared with EEG results.

No images from phase 0 were conclusive, in accordance with the study inclusion criteria, and in phase 1, 36 MR-only images were positive. Joint PET/MRI reading in phase 2 revealed that 46 patients had PET-positive/MRI-positive results, 24 had PET-positive/MRI-negative results and eight had PET-negative/MRI-negative results. In phase 3, PET-positive/MRI-positive findings demonstrated high accuracy in identifying lesions compared with EEG results, particularly focal cortical dysplasia.

The study also identified two distinct groups of patients showing hypometabolism, or reduced brain metabolism. In the first hypometabolic group, careful reevaluation of the MRI scans revealed structural brain abnormalities. In the second group, areas of abnormal hypometabolism were often mild, and no conclusive brain lesions were found on MRI even after detailed review. These children were much more likely to have EEG and clinical findings that did not match the imaging results, making them less likely candidates for epilepsy surgery.

Based on the clinical, imaging and EEG data, 24 patients underwent surgery, and five underwent thermocoagulation to remove brain tissue. Of these children, 76% were seizure-free after two years of follow-up.

“These findings highlight the important role of molecular imaging and nuclear medicine in evaluating children with focal epilepsy, demonstrating that PET/MRI can be used safely and reliably even in very young patients,” noted Concetta Luisi, MD, a pediatric neurologist and epileptologist at the Neurology, Epilepsy and Movement Disorders Unit of Bambino Gesù Children’s Hospital in Rome, Italy. “As more data become available, this approach could help clinicians identify the children most likely to benefit from epilepsy surgery, better understand distinct patterns of brain metabolism, and improve the integration of imaging findings with clinical and EEG data to guide treatment decisions.”

Provided by
Society of Nuclear Medicine and Molecular Imaging

Who’s behind this story?

Gaby Clark

MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news.

Full profile →

Advertisements

Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

Full profile →

See also  What in the World - Will the PCOS name change help young women get treatment?