Radioimmunotherapy (RIT) may improve the management of malignant gliomas. A 
Phase I clinical trial was performed to evaluate, for the first time, the 
toxicity and clinical effect of an intracavitary administration of a single dose 
of Nimotuzumab (h-R3) labeled wit (188)Re. Nimotuzumab is a humanized monoclonal 
antibody directed against epidermal growth factor receptors. Three patients with 
anaplastic astrocytoma (AA) and 8 with glioblastoma multiforme (GBM) were 
intended to be treated with 3 mg of mAb labelled with 10 or 15 mCi of (188)Re. 
In patients treated with 10 mCi (n=6) transitory worsening of pre-existing 
neurological symptoms were observed. Two patients treated with 15 mCi (n=4) 
developed early severe neurological symptoms and one also developed late severe 
toxicity (radionecrosis). In the group treated with 10 mCi, 1 GBM patient died 
in progression 6 months after the treatment, 2 patients (1 GBM and 1 AA) 
developed stable disease during 3 months. One GBM patient had partial response 
for more than 1 year and 2 patients (1 GBM and 1 AA) were asymptomatic and in 
complete response after 3 years of treatment. Maximal tolerated dose of the 
radioimmunoconjugate (188)Re-Nimotuzumab was 3 mg of the h-R3 labelled with 10 
mCi of (188)Re. The radioimmunoconjugate showed a high retention in the surgical 
created resection cavity and the brain adjacent tissues with a mean value of 
85.5 % of the injected dose one hour post-administration. This 
radioimmunoconjugate may be relatively safe and a promising therapeutic approach 
for treating high grade gliomas.