Permanent iodine-125 interstitial implants for the treatment of recurrent glioblastoma multiforme

OBJECTIVE: Brachytherapy with temporary implants may prolong survival in pa tients with recurrent glioblastoma multiforme (GBM), but it is associated w ith relatively high costs and morbidity. This study reports the time to pro gression and survival after permanent implantation of iodine-125 seeds for recurrent CBM and examines factors predictive of outcome. METHODS: Forty patients with recurrent GEM were treated with maximal resect ion plus permanent placement of iodine-125 seeds into the tumor bed. A tota l dose of 120 to 160 Gy was administered, and patients were followed up wit h magnetic resonance imaging scans every 2 to 3 months. RESULTS: Actuarial survival from the time of implantation was 47 weeks, wit h 7 of 40 patients still alive at a median of 59 weeks after implantation. Survival was significantly better for patients younger than 60 years, and a trend for longer survival was demonstrated with gross total resection and tumors with a low MIB-1 (a nuclear antigen present in all cell cycles of pr oliferating cells) staining index. Median time to progression was 25 weeks and, on multivariate analysis, was favorably influenced by gross total rese ction and patient age younger than 60 years. After implantation, 27 of 30 p atients with failure had a local component to the failure. No patient devel oped symptoms attributable to radiation necrosis or injury. CONCLUSION: Permanent iodine-125 implants for recurrent GEM result in survi val comparable with that described in previous reports on temporary implant s, but with less morbidity. Results are most favorable for patients who are younger than 60 years, and who undergo gross total resection. Despite this aggressive treatment, most patients die as a consequence of locally recurr ent disease.