Pharmacokinetics and dose estimates following intrathecal administration of 131I-monoclonal antibodies for the treatment of central nervous system malignancies.

Purpose: Treatment of malignant disease in the central nervous system (CNS) with systemic radiolabeled monoclonal antibodies (MoAbs) is compromised by poor penetration into the cerebrospinal fluid (CSF), limited diffusion into solid tumors, and the generation of anti-mouse antibodies. To attempt to avoid these problems we have treated patients with diffuse neoplastic meningitis with radioimmunoconjugates injected directly into the intrathecal space.

Methods And Materials: Tumor-specific MoAbs were conjugated to Iodine-131 (131I) (629-3331 MBq) by the Iodogen technique, and administered via an intraventricular reservoir.

Treatment of recurrent and cystic malignant gliomas by a single intracavity injection of 131I monoclonal antibody: feasibility, pharmacokinetics and dosimetry.

A pilot study was undertaken to determine the feasibility of infusing 131I labelled monoclonal antibodies (MoAbs) into either the cavity remaining after resection of malignant glioma or into glioma cysts. Of the seven patients recruited into the study, two had cystic lesions and five resection cavities. Six of the seven were treated after relapse from primary therapy.