Inr. J Rdiatm Ondog? Bd. Phw Vol. 21. pp. MlI-606 Pnnted I” the U S.A. All nghts reserved. 0360.3016/91 $3.00 + .I0 Copyright C 1991 Pergamon Press plc ?? Original Contribution EXTERNAL IRRADIATION FOLLOWED BY AN INTERSTITIAL HIGH ACTIVITY IODINE-125 IMPLANT “BOOST” IN THE INITIAL TREATMENT OF MALIGNANT GLIOMAS: NCOG STUDY 6G-82-2 PHILIP H. GUTIN, M.D.,‘.* MICHAEL D. PRADOS, M.D. ,t THEODORE L. PHILLIPS, M.D. ,* WILLIAM M. WARA, M.D.,2 DAVID A. LARSON, M.D., PH.D.,* STEVEN A. LEIBEL, M.D.,* PENNY K. SNEED, M.D. ,* VICTOR A. LEVIN, M.D.,’ KEITH A. WEAVER, PH.D. ,* PAMELA SILVER, B.A.,’ KATHLEEN LAMBORN, PH.D.,3 SHARON LAMB, R.N.’ AND BRIGID HAM, R.N.’ ‘Brain Tumor Research Center, Department of Neurological Surgery and 2Department of Radiation Oncology, School of Medicine, University of California, San Francisco, CA; and 3Northem California Oncology Group, Belmont, CA Between January 1982 and January 1990, 107 patients with unifocal, circumscribed malignant gliomas partic- ipated in a non-randomized trial testing brachytherapy in their initial treatment. Focal external irradiation (6000 cGy) was combined with an implant of high-activity iodine-125 (5000-6000 cGy) and six courses of pro- carbazine, lomustine, and vincristine. Of the 101 evaluable patients, 63 received implants. Of these, 29 had non-glioblastoma anaplastic gliomas, and 34 had glioblastoma multiforme. The other 38 did not receive im- plants, in most cases because radiation therapy failed to reduce the size of the tumor. The median survival was 165 weeks for all evaluable patients with non-glioblastoma anaplastic gliomas, 157 weeks for those with im- plants, 67 weeks for all evaluable glioblastoma patients, and 88 weeks for those with implants. Of the glioblas- toma patients with implants, nine were alive after 2 years, and three were alive after 3 years. In each of the groups, nearly half the patients underwent reoperation for clinical deterioration, increasing steroid depen- dency, and increasing mass effect at the implantation site after 46.1 weeks (median) for glioblastoma multi- forme and 41.3 weeks for non-glioblastoma patients. Karnofsky Performance Scores showed only a small decline in performance after brachytherapy. Patients receiving implants for non-glioblastoma anaplastic glio- mas had a mean Karnofsky Performance Score of 91% (range 90-100%) after 1 month and 78% (range 60- 100%) 30 months after brachytherapy. Those treated for glioblastoma multiforme had a mean Karnofsky Performance Score of 86% (range 6&100%) at 1 month and 75% (range 60-100%) at 24 months. The quality of life of treated patients appears to be satisfactory. On the basis of comparisons with previous studies, we conclude that a brachytherapy “boost” after external irradiation may be valuable for some patients with glio- blastoma multiforme but not for those with non-glioblastoma anaplastic gliomas. Malignant glioma, Glioblastoma multiforme, Interstitial brachytherapy, Iodine-125, Stereotaxy. INTRODUCTION locally treatable just after external beam therapy (3). Sec- Brachytherapy has proven the treatment of choice for the ond, patients with malignant gliomas survive longer with selected recurrent malignant gliomas that are amenable to increasing radiation doses (23). Finally, because local re- this treatment by virtue of their size and location (8, 10, currence rather than distant metastasis is the rule, aggres- 16). Brachytherapy is important in the treatment of cancers sive local treatment may greatly improve tumor control and at many sites as a “boost” to the external beam radiation outcome for patients with these tumors (4, 13, 24). Here dose (l), and it is logical to use brachytherapy to increase we report the results of trial 6G-82-2 by the Northern Cal- the local dose to malignant gliomas in the primary treat- ifomia Oncology Group (NCOG) using brachytherapy as a ment of these tumors for the following reasons. First, ma- “boost” to external beam irradiation in the initial treat- lignant gliomas are most circumscribed and therefore most ment of malignant gliomas. Presented in part at the American Society for Therapeutic Ra- diology and Oncology Annual Meeting, Miami Beach, Florida, October 18, 1990. Accepted for publication 22 February 199 1. Reprint requests to: Philip H. Gutin, M.D., Department of Neurological Surgery, c/o The Editorial Office, 1360 Ninth Ave- 601 nue, Suite 210, San Francisco, CA 94122. Supported by the UCSF Brain Tumor Research Center Pro- gram Project Grant CA 13525 and by Grants CA 21744, CA 25827, CA 39098, and CA 19408 to the Northern California Can- cer Center and its member institutions from the National Cancer Institute, National Institutes of Health, Bethesda, Maryland.