Radioimmunotherapy of gastrointestinal cancer and glioblastomas.

Two groups of patients with gastro-intestinal (GI) tumours (41) and recurrent glioblastoma (GBM), (17) underwent radioimmunotherapy after the failure of traditional treatments. A number of different MAbs were employed (anti-CEA and anti-Tenascin) which were labelled with I-131. The radiopharmaceuticals were administered by the intraperitoneal and intratumoral routes. As a rule the cycles were repeated to enhance the effectiveness of RIT. No significant early or late adverse effects were recorded. HAMA development was observed in all GI cases but only in a few GBM patients. The cumulative dose delivered to the target tumors was considerable (mean 8,900 cGy) in the GI group, and was much higher in the GBM patients (mean 51,700 cGy) owing to the particular modality of injection. Survival improved in both series of patients. The objective responses to RIT were promising: in the GI group 10 complete remissions (CR) and 6 partial remissions (PR) were observed, while in the GBM group 3 long-lasting CRs and 3 prolonged PRs were documented.