PET Imaging of Peripheral Benzodiazepine Receptors in Patients With Neurocysticercosis Using [C-11]PBR28

Objective

In endemic regions neurocysticercosis is the most common cause of adult acquired epilepsy and thus an important public health problem. The disease is caused by infection with the larval form of the tapeworm, Taenia solium. Although neurocysticercosis is common only in many developing regions, an increased number of patients are diagnosed in developed countries mostly due to immigration of infected individuals.

The peripheral benzodiazepine receptor (PBR) can be a clinically useful marker to detect neuroinflammation because activated microglia in inflammatory areas expresses much greater levels of PBR than in microglia in resting conditions. PBR has been imaged with positron emission tomography (PET) using [(11)C]1-(2-chlorophenyl-N-methylpropyl)-3-isoquinoline carboxamide (PK11195), which provides low levels of specific signal. Recently we developed a new ligand, [(11)C]N-acetyl-N-(2-methoxybenzyl)-2-phenoxy-5-pyridinamine (PBR28), which showed much greater specific signal than [(11)C]PK11195 in non-human primates.

The major objective of this protocol is to assess the utility of [(11)C]PBR28 PET to detect neuroinflammation in patients with neurocysticercosis.

Study population