263 Intralesional radioimmunotherapy of malignant gliomas as adjuvant setting in newly diagnosed tumour or as rescue treatment in recurrent lesions

Abstract

Two I-131 labelled murine Monocolonal Antibodies (MAbs) BC-2 and BC-4 raised against tenascin (TN), were intralesionally infused in 48 patients bearing a malignant glioma: 28 with recurrent disease (Rec) and 20 cases with newly diagnosed tumour (New). All patients were previously treated with surgery and radio-chemotherapy. Twenty-four Rec cases underwent further surgery which obtained a total or subtotal removal of tumour mass in 10 of these. In total 25 patients had intralesional RIT when the disease was minimal. The radiopharmaceutical was given at a dose of 4 mg of MAbs and 2405 MBq of 131 I. The infusions were repeated up to six. The local treatments were always well tolerated. The radiation dose to the tumour was on average >300 Gy per cycle. The median survival was, in total, 18 months. Intralesional RIT produced 12 complete remissions (6 in Rec and 6 in New), 6 partial remissions (4 in Rec and 2 in New). In 19 cases (15 Rec and 5 New) the progression of disease was recorded. The overall response rate was 37.5% (35.7% in Rec and 40% in New). These data demonstrate the capability of this new therapeutic technique to achieve, in a significant number of cases, a long lasting control of malignant gliomas and suggest the opportunity to apply this treatment when the disease is reduced owing to previous traditional cares. (Work supported by National Research Council program (Italy): Clinical Applications of Oncology Research, subproject n.8.)