Showing papers by "Michael D. Prados published in 1990"

Hyperfractionated irradiation for adults with brainstem gliomas

Abstract: Hyperfractionated irradiation appears to have improved survival for pediatric patients with brainstem gliomas However, the efficacy and safety of this technique are less well established for adults with brainstem tumors. In 1984 the UCSF Department of Radiation Oncology began treating adults with brainstem gliomas using 100 cGy fractions given twice daily to total doses ranging between 6600–7800 cGy (median dose 7200 cGy). By the end of 1989, a total of 14 patients had been irradiated with follow-up times for surviving patients ranging between 4–69 months (median follow-up 33 months). Tumor histologies included five moderately anaplastic astrocytomas, one highly anaplastic astrocytoma, and eight which were unbiopsied. At the time of this analysis, six patients had failed locally, with five dying as a result of recurrent tumor. There were no deaths caused by complications or intercurrent illness. The 3-year actuarial survival rate was 59%, with a corresponding 3-year actuarial local control rate of 48%. The projected median survival was in excess of 5 years, whereas the actuarial median time to progression was 31 months (134 weeks). The treatments were well tolerated: the mean pretreatment Karnofsky Performance Status was 74% (range 60–90%); at the end of treatment the mean KPS was 78% (range 60–100%). In terms of neurologic status, six patients improved by the end of treatment, seven were stable, and one experienced only minor deterioration without change in KPS. There were no significant long-term complications (specifically, no instances of either radiation brain necrosis or myelitis). Seven patients required prolonged steroid administration after completing radiotherapy; six of these eventually recurred locally. These results appear to be substantially better than those achieved using conventional radiotherapy regimens, and suggest that this technique merits further investigation.

Stereotaxic interstitial iodine-125 “boost” in the initial management of malignant gliomas

Abstract: Brachytherapy has proven the treatment of choice for selected recurrences of malignant gliomas. We tested the use of brachytherapy in the adjuvant treatment of these tumors when between Jan. 3, 1983 and Nov. 1 1989 we treated patients after biopsy or surgical resection of unifocal, supratentorial, and radiographically-circumscribed (eimplantable") glioblastoma multiforme (GM) or non-glioblastoma anaplastic astrocytoma (NOM) with external irradiation to the tumor volume (6000 rad), with concomitant hydroxyurea, followed by a stereotaxically-placed temporary implant with high-activity iodine-125 (5000 rad). Patients were then placed on a regimen of procarbazine, CCNU, and vincristine for 6 courses. Eighty-eight patients were entered into this NC00 protocol , with 4 dying during or immediately after external irradiation and 29 (22 GM , 7 NGM) not receiving an implant for various other reasons, the majority (62%) because the tumor had grown during irradiation. Twenty-five patients with NOM and 30 patients with GM received implants and are considered evaluable. At the time of analysis 56% of evaluable patients with NGU were alive with a median survival of 157 weeks while 43% of GM patients were alive with a median survival of 88 weeks. Twenty-five of the evaluable patients (45%) underwent reoperation after implant because of clinical deterioration and increasing steroid dependency. Other patients were treated with the same adjuvant brachytherapy regimen but were not registered with the NCOG because of geographic considerations. The median survival for the additional 27 patients with NGM was 142 weeks, and for the 50 with GM it was 83 weeks, both values close to those of patients registered with NCOG. Thirty-five patients with NGM and 33 with GM were uimplantablel~ but for various reasons were treated on another NCOG protocol of external beam irradiation given with bromodeoxyuridine (BUdR) infusion. Since these uimplantablee patients were treated concurrently with the brachytherapy patients, the two groups were compared. The median survival for the BUdR-treated patients with NGM was 199 weeks and that for those with GMwas 60 weeks. We conclude that for selected patients with GM, but not NGM, an interstitial eboostw is an advantage. Hyperthermia with brachytherapy is already being used at our center for selected recurrences of both GM _and NOM, and a trial integrating hyperthermia and brachytherapy into the adjuvant treatment of GM is being designed.