Simultaneous radiotherapy and radioimmunotherapy of malignant gliomas with anti-EGFR antibody labelled with iodine 125. Preliminary results.

Background: In this paper we present the preliminary results of a prospective trial of the efficacy of simultaneous radiotherapy and anti-EGFR (125)I radioimmunotherapy of malignant gliomas with 2 years' total survival as the end-point, raising the question whether anti-EGFR (125)I radioimmunotherapy influences the disease-free survival in these patients.

Material And Methods: Patients with anaplastic astrocytoma or primary glioblastoma were previously treated by a macroscopically radical neurosurgical approach and randomized either to radiotherapy + radioimmunotherapy arm or treated by radiotherapy alone. Seven patients were included in the group with radioimmunotherapy, among them five with GBM and two with AA, and five patients in the control arm. Patients were irradiated to 60 Gy using three-dimensional conformal noncoplanar techniques. Anti-EGFR (125)I monoclonal antibody 425 radioimmunotherapy (50 mCi/course) was started during 4th week of radiotherapy and was repeated three times in one week intervals.

Results: Time of follow-up ranges between 2 and 10 months in the anti-EGFR (125)I radioimmunotherapy arm and 4 and 9 months in the control arm. Recurrence was diagnosed in all patients in the EGFR (125)I group with a lethal outcome in two of them and in 4 patients in the control group. Median time to recurrence was 2 and 5 months respectively.

Conclusions: Taking into account early recurrences observed, we propose to continue the studies on the efficacy of adjuvant anti-EGFR (125)I radioimmunotherapy in a selected group of patients in whom the greatest benefit may be expected on the basis of molecular studies, among them EGFR expression investigation.