Patterns of failure following treatment for glioblastoma multiforme and anaplastic astrocytoma

Re-operations of supratentorial anaplastic astrocytomas

Results of re-operations of 99 adult patients with recurrent supratentorial lobar glioblastomas (60 patients) and anaplastic astrocytomas (39 patients) have been reviewed. In all cases both surgical interventions were performed at the same institute. Age of patients with glioblastoma varied between 19 and 64 and with anaplastic astrocytoma between 21 and 68 years, with a mean value of 48 and 36 years, respectively. The median interval between the first and second operations was 47 weeks for patients with glioblastoma and 83 weeks with anaplastic astrocytoma. The mortality rate of the re-operations was 3%. Following re-operation radio- and/or chemotherapy was applied in most of the cases. Median survival time after re-operation was 18.5 weeks in patients with glioblastoma and 55 weeks with anaplastic astrocytoma. Survival curves were calculated according to Kaplan-Meier method and for statistical evaluation the generalized Wilcoxon test and multiple linear regression method were used. Histologically lower grade tumour at the first operation and longer interval between the two operations proved to influence positively and dedifferentiation of the primary tumour negatively the survival time.

Macroscopic tumor volume of malignant glioma determined by contrast-enhanced magnetic resonance imaging with and without magnetization transfer contrast

The purposes of this study were to compare the conspicuity and lesion volume of contrast-enhancing macroscopic malignant glioma determined by postcontrast magnetic resonance (MR) imaging with and without magnetization transfer (MT) saturation, and to discuss possible implications for radiotherapy planning. Nineteen patients (age 24-60 years) with histologically proven malignant glioma were prospectively examined by MR imaging. After the administration of gadolinium dimeglumine (0.1 mmol/kg body weight), the lesions were imaged with an MT-weighted FLASH (fast, low-angle shot) pulse sequence and with a conventional T1-weighted spin-echo (SE) sequence without MT saturation. The mean tumor volumes of gliomas measured on MT-weighted FLASH images were significantly (p < .01) larger than those obtained from T1-weighted SE images (45 +/- 15 cm3 vs. 33 +/- 10 cm3). The mean contrast-to-noise ratio of enhancing lesions on MT-weighted FLASH was 48 +/- 14 compared with 30 +/- 14 on SE images, representing a significant (p < .01) improvement. We conclude that the volume of contrast enhancement of malignant glioma identified on MT-weighted FLASH images represents the area of disrupted blood-brain barrier. If this volume of subtle contrast enhancement is caused by tumor infiltration and represents the boost target volume for stereotactic radiosurgery or brachytherapy, MT-weighted FLASH images would be better than T1-weighted SE images to define these volumes. These improved delineation of areas at highest risk for recurrence following radiation therapy should enhance the efficacy of treatment planning for high-boost therapy.

Stereotactic radiosurgery as an adjunct to surgery and external beam radiotherapy in the treatment of patients with malignant gliomas

PURPOSE

To evaluate the efficacy and toxicity of a stereotactic radiosurgery boost as part of the primary management of a minimally selected population of patients with malignant gliomas.

METHODS AND MATERIALS

Between June, 1991 and January, 1994 a stereotactic radiosurgery boost was given to 30 patients after completion of fractionated external beam radiotherapy. The study population consisted of 22 males and 8 females, with a range in age at treatment from 5 to 74 years (median: 54 years). Tumor volume ranged from 2.1 to 115.5 cubic centimeters (cc) (median: 24 cc). Histology included 17 with glioblastoma multiforme, 10 with anaplastic astrocytoma, 1 with a mixed anaplastic astrocytoma-oligodendroglioma, and 2 with a gliosarcoma. A complete resection was performed in 9 (30%) patients, while 18 (60%) underwent a subtotal resection, and 3 (10%) received a biopsy only. Fractionated radiation dose ranged from 44 to 62 Gy, with a median of 59.4 Gy. Prescribed stereotactic radiosurgery dose ranged from 0.5 to 18 Gy (median: 10 Gy), and the volume receiving the prescription dose ranged from 2.1 to 158.7 cc (median: 46 cc). The volume of tumor receiving the prescription dose ranged from 70-100% (median: 100%). One to four (median: 2) isocenters were used, and collimator size ranged from 12.5 to 50 mm (median size: 32.5 mm). The median minimum stereotactic radiosurgery dose was 70% of the prescription dose and the median maximum dose was 200% of the prescription dose.

RESULTS

With a minimum follow-up of 1 year from radiosurgery, 7 (23%) of the patients are still living and 22 (73%) have died of progressive disease. One patient died of a myocardial infarction 5 months after stereotactic radiosurgery. Follow-up for living patients ranged from 12 to 45 months, with a median of 30 months. The 1- and 2-year disease-specific survival from the date of diagnosis is 57 [95% confidence interval (CI) 39 to 74%] and 25% (95% CI 9 to 41%), respectively (median survival: 13.9 months). No significant acute or late toxicity has been observed.

CONCLUSION

Stereotactic radiosurgery provides a safe and feasible technique for dose escalation in the primary management of unselected malignant gliomas. Longer follow-up and a randomized prospective trial is required to more thoroughly evaluate the role of radiosurgery in the primary management of malignant gliomas.

Hyperfractionated and hypofractionated radiation therapy for human malignant glioma xenograft in nude mice

Xenografts of a human malignant glioma subcutaneously transplanted into nude mice were irradiated with graded single doses (2, 5, 10 or 20 Gy) or five types of fractionation schedules in two weeks: conventional [20 Gy in 10 fractions (fr)], hyperfractionated [24 Gy in 20 fr (two fractions per day)], and hypofractionated-1, 2, 3 [20 Gy, 18 Gy, 16 Gy in 4 fr]. All of the fractionated irradiation groups showed tumor regression. The hypofractionation-1 group (20 Gy in 4 fr) demonstrated the most prominent tumor regression, while the hyperfractionation group (24 Gy in 20 fr) showed the least effect. The hypofractionation-2 group (18 Gy in 4 fr) showed similar regression to the conventional fractionation group (20 Gy in 10 fr). Histologically, tumors in the control groups consisted of a homogenous population of small anaplastic cells, and only a small number of tumor cells were glial fibrillary acidic protein (GFAP)-positive. Following irradiation, the population of small anaplastic cells decreased and the percentage of GFAP-positive cells increased. Cellular pleomorphism became much more prominent after irradiation in all of the fractionated irradiation groups as compared with the graded single dose irradiation groups. In this study, hyperfractionation was not effective against human glioma xenografts compared with conventional fractionation and hypofractionation. This indicates that care is needed in applying hyperfractionation regimens to human malignant gliomas.

Radiosurgery in the initial management of malignant gliomas: survival comparison with the RTOG recursive partitioning analysis. Radiation Therapy Oncology Group

PURPOSE

To evaluate the impact of stereotactic radiosurgery on the survival of patients treated with malignant gliomas.

METHODS AND MATERIALS

A total of 115 patients from three institutions (75 from the Joint Center for Radiation Therapy, 30 from the University of Wisconsin, and 10 from the University of Florida) were treated with a combination of surgery, external beam radiation therapy, and linac-based radiosurgery as part of similar institutional protocols from March 1988 through July 1993. Patients were stratified into six prognostic classes (classes 1-6) based on the recursive partitioning analysis of multiple prognostic factors previously reported by the Radiation Therapy Oncology Group.

RESULTS

The actuarial 2-year and median survival for all patients analyzed was 45% and 96 weeks, respectively. In comparison to the results from a previously published analysis of 1578 patients entered on three Radiation Therapy Oncology Group external beam radiotherapy protocols from 1974 to 1989, those patients treated with radiosurgery had a significantly improved 2-year and median survival (p = 0.01) corresponding with a standardized mortality risk ratio of 0.51 [95% confidence interval (CI): 0.31, 0.85]. This improvement in survival was seen predominantly for the worse prognostic classes (classes 3-6). The 2-year survival for the radiosurgical patients compared with the previously reported patients was 81% vs. 76% for classes 1/2, 75% vs. 35% for class 3, 34% vs. 15% for class 4, and 21% vs. 6% for classes 5/6, respectively. Although Karnofsky performance status and prognostic class were significant on univariate analysis, only the Karnofsky score was a significant predictor of outcome on multivariate analysis. Median and 2-year survival for patients with a Karnofsky score > or = 70 was 106 weeks and 51%, respectively, as compared to 38 weeks and 0% for patients with a Karnofsky score < 70% (p = 0.001).

CONCLUSIONS

The addition of radiosurgery to conventional treatment (surgery and external beam radiotherapy) of malignant gliomas appears to improve survival when compared to historical reports. These results should be interpreted with caution because the recursive partitioning model does not completely predict the prognosis of the patients treated in the present study. Although this study suggests that radiosurgery may prolong survival in patients with malignant gliomas, the role of radiosurgery in the management of these patients remains to be defined by a prospective randomized trial.

The relationship between the technical accuracy of stereotactic interstitial implantation for high grade gliomas and the pattern of tumor recurrence

PURPOSE

To correlate the pattern of failure and subsequent survival with the technical accuracy of stereotactic brain tumor implantation.

METHODS AND MATERIALS

The patterns of failure of 47 consecutive patients with primary or recurrent gliomas after stereotactic implantation delivering 60 Gy via removable high activity 125I sources were reviewed. When the tumor was covered at all levels by the chosen isodose distribution, the implant was considered to be "ideal." If the coverage was not complete, a numerical description of the volume of tumor outside the isodose was assigned. Criteria for "adequate" and "inadequate" implants were defined. Standard radiographic criteria, with pathologic confirmation in 26 cases, were used to categorize the patterns of failure into the following components: central, peripheral, distant (within the brain parenchyma), leptomeningeal, and spinal. A peripheral failure was scored as being in the "direction of error" when the prescribed isodose did not cover the tumor volume and the subsequent tumor progression was in this region. Survival was calculated from the date of implantation.

RESULTS

Of 47 cases examined, 72% had an element of central and/or peripheral failure and 23% had a component of distant or meningeal failure. Among the patients with "adequate" or "inadequate" ("nonideal") implants who had a component of peripheral failure, only 19% were in the "direction of error." All patients with technically "inadequate" implants progressed in both the central and peripheral region. Among the groups who had "ideal," "adequate," and "inadequate" implants; 37%, 70%, and 75%, respectively, underwent reoperation [p = not significant (NS)]. Patients who underwent reoperation had a longer median survival than those who did not; 521 days vs. 298 days, respectively (p = 0.035). For patients with "nonideal" implants, a median survival of 470 days was found for patients undergoing reoperation vs. 184 days for those who did not (p = 0.016).

CONCLUSIONS

(a) Patients with "inadequate" implants failed in both the central and peripheral region in all cases. This pattern, while less common in those with "ideal" or "adequate" implants, occurred in the majority of cases. (b) The technical excellence of the implant had no impact on survival. (c) Patients with "nonideal" implants were more likely to have reoperation than those with "ideal" implants, and this intervention was associated with a significant survival advantage.

Stereotactic radiosurgery for glioblastoma: a final report of 31 patients

From February 1989 to December 1992, 31 patients who presented with an initial pathological diagnosis of glioblastoma multiforme underwent tumor debulking or biopsy, stereotactic radiosurgery, and standard radiation therapy as part of their primary treatment. Presenting characteristics in the 22 men and nine women included a median age of 57 years, Karnofsky Performance Scale score median of 80, and median tumor volume of 16.4 cm3. Stereotactic radiosurgery delivered a central dose of 15 to 35 Gy with the isocenter location, collimator size, and beam paths individualized by means of three-dimensional software developed at the University of Wisconsin. The peripheral isodose line varied from 40% to 90% with a median of 72.5% and a mode of 80%. The mean follow-up period was 12.84 months with a median of 9.5 months. Statistical analysis was performed using Kaplan-Meier analysis and log-rank comparison of risk factor groups. The parameters of age, initial Karnofsky Performance Scale score, and biopsy were significantly different in patient survival from debulking; but no difference was noted between single and multiple isocenters and patterns of steroid requirement. Radiographic recurrences were divided by location into the following categories: central (within central stereotactic radiosurgery dose), 0; peripheral (within 2 cm of central dose), 19; and distant (> 2 cm), 4. There is no evidence of recurrence in five surviving patients. Actuarial 12-month survival was 37%, with a median survival of 9.5 months. These values are similar to previous results for surgery and standard radiotherapy alone. The results suggest that the curative value of radiosurgery is significantly limited by peripheral recurrences.

Permanent iodine-125 implants in the up-front treatment of malignant gliomas

Between July 1989 and July 1992, 58 patients with newly diagnosed, histologically confirmed malignant gliomas (40 anaplastic astrocytomas, 18 glioblastoma multiforme) underwent implantation with low-activity iodine-125 sources. Patients were considered appropriate candidates for brachytherapy if their Karnofsky scores were > or = 70 and their contrast-enhancing tumors were < 6 cm in maximum diameter. Tumor volumes ranged from 0.1 to 90 ml. Ten patients had implants only. The other 48 patients received additional external beam radiation; 38 patients received radiation 1 to 2 weeks after the implant, and 10 patients received radiation preceding the implant. Median survival has not been reached but is currently greater than 31 months for patients with anaplastic astrocytoma and greater than 23 months for patients with glioblastoma. The rate of second operation for this group of patients was 45% (26 patients). Brain necrosis requiring resection occurred in 11 patients (19%). Although further follow-up is required, we conclude that low-activity permanent iodine-125 implants provide patients who have newly diagnosed malignant gliomas long-term survival with an acceptable risk of late complications.

Low grade gliomas: preliminary analysis of failure patterns among patients treated using 3D conformal external beam irradiation

PURPOSE

The pattern of failure of low grade gliomas following radiotherapy is less well known than that of the high grade gliomas. Stereotactic histologic studies have suggested that tumor cells extend beyond imaging abnormalities, and that large margins would be required for radiotherapy target volumes to encompass all of the neoplasm. Our experience using computerized tomography (CT)- and magnetic resonance (MR)-planned irradiation of low grade gliomas was reviewed to determine the pattern of tumor recurrence, in an effort to clinically define the minimum margin required.

METHODS AND MATERIALS

Forty-six patients with low grade supratentorial gliomas were treated between April 1985 and November 1992 using three-dimensional (3D) conformal CT- or MR-planned external beam radiotherapy. Fields were designed to encompass a target volume created by adding a margin to the tumor in three dimensions. Generally, patients were treated using shrinking fields with an initial target (tumor plus a 1 to 3 cm margin) treated to a dose of 45 to 50.4 (median 50.4) Gy, and a boost (tumor plus a 0 to 2 cm margin) treated to a total of 54 to 59.4 (median 59.4) Gy. Median follow-up was 32.9 months.

RESULTS

There have been 11 failures; all of these occurred within the radiographic abnormality (either T2 prolongation or CT hypodensity) visualized at the time of treatment planning (i.e., all failures were within the boost volume). Median time to failure was 53 months. Because all failures were local, there was no relationship between the amount by which the tumor volumes were expanded to create target volumes and the eventual outcome.

CONCLUSION

Despite pathologic data suggesting that low grade glioma cells can be found outside the MR T2-signal abnormality in many cases, our results demonstrate that conformal external beam radiotherapy, in which the high dose volume is limited, does not result in increased marginal or out-of-field failures. Until control of tumor within the radiographically abnormal volume can be achieved, the need for large fields to treat prophylactically microscopic disease beyond the visualized tumor volume is questionable. The use of conformal fields might be associated with reduced toxicity, and thereby allow delivery of higher total doses to the central tumor.

Comparison of stereotactic radiosurgery and brachytherapy in the treatment of recurrent glioblastoma multiforme

The purpose of this study was to compare the efficacy of stereotactic radiosurgery (SRS) and brachytherapy in the treatment of recurrent glioblastoma multiforme (GBM). The patients had either progressive GBM or pathologically proven GBM at recurrence after previous treatment for a lower grade astrocytoma. Thirty-two patients were treated with interstitial brachytherapy, and 86 received treatment with stereotactic radiosurgery (SRS). The patient characteristics were similar in the two groups. Those patients treated with SRS had a median tumor volume of 10.1 cm3 and received a median peripheral tumor dose of 13 Gy. Patients treated with brachytherapy had a median tumor volume of 29 cm3. Median dose to the periphery of the tumor volume was 50 Gy delivered at a median dose rate of 43 cGy/hour. Twenty-one patients (24%) treated with SRS were alive, with a median follow-up of 17.5 months. Median actuarial survival, measured from the time of treatment for recurrence, for all patients treated with SRS was 10.2 months, with survivals of 12 and 24 months being 45 and 19%, respectively. A younger age and a smaller tumor volume were predictive of better outcome. The tumor dose, the interval from initial diagnosis, and the need for reoperation were not predictive of outcome after SRS. Five patients (16%) treated with brachytherapy were alive, with a median follow-up of 43.3 months. The median actuarial survival for all patients treated with brachytherapy was 11.5 months. Survivals of 12 and 24 months were 44 and 17%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

External beam radiotherapy: hard facts and painful realities

In comparison to whole brain radiotherapy, local field radiotherapy in a consecutive series of 100 patients with malignant astrocytoma resulted in remarkably less toxicity. Survivorship is not different; the advantage is limited to the 7% long term survivors (defined as living 100% or more beyond median) since toxicity from brain radiation does not occur until a year or more after treatment.

Stereotactic radiosurgery for glioblastoma multiforme: report of a prospective study evaluating prognostic factors and analyzing long-term survival advantage

PURPOSE

Prospective evaluation of the toxicity and efficacy of radiosurgery with external beam radiotherapy in the management of newly diagnosed glioblastoma.

METHODS AND MATERIALS

From 5/89 to 12/92, 31 out of 51 patients with glioblastoma multiforme underwent radiosurgery, in addition to 54 Gy in 1.8 Gy/fraction following biopsy (n = 12) or resection (n = 19). Eligibility required supratentorial glioblastoma, tumor not > 4 cm in > 1 axis, age > 18 years, and location > 1 cm from optic chiasm. Patient characteristics were: age 20-78 years (median = 57); 22 male, 9 female; Karnofsky score 20-90 (m = 70), and volume of 2.3-59.7 c.c. (m = 17.4). Eighteen patients were treated with 1 collimator, 5 with 2, 7 with 3, and 1 with 4; peripheral isodoses were 40-90% (m = 72.5) and minimum and maximum tumor dose ranges were 10-20 (m = 12) and 15-35 Gy (m = 18.75). Patients were followed clinically and radiographically every 8-12 weeks to analyze survival, quality of life, and toxicity.

RESULTS

With a follow-up of 12-171 weeks, 8 out of 31 (26%) patients are alive. Median survival is 42 weeks. Twelve and 24-month actuarial survival are 38 and 28%. Comparison of the 2-year survival with previous Radiation Therapy Oncology Group patients was carried out using a nonparametric recursive partitioning technique and the observed vs. expected values are 28 vs. 9.7% (p < 0.05). Extent of resection and performance status were associated with improved survival in a multivariate analysis. No significant acute toxicity was encountered. Four patients (13%) developed clinically significant necrosis verified by biopsy or positron emission tomography scan at 9-59 weeks after radiosurgery.

CONCLUSION

The improvement in median survival in broadly selected glioblastoma patients treated with radiosurgery is difficult to determine, but the 2-year survival may be superior. Future randomized trials of radiosurgery are recommended, and ad hoc use of this modality should be discouraged.

Patterns of recurrence of glioblastoma multiforme after external irradiation followed by implant boost

PURPOSE

To study patterns of recurrence in patients with focal primary glioblastoma treated on Northern California Oncology Group protocol 6G-82-2 including surgery, focal external beam radiotherapy (59.4-60 Gy) with oral hydroxyurea followed by temporary brain implant with high-activity iodine-125 sources (50 Gy), and six cycles of chemotherapy with procarbazine, lomustine, and vincristine.

METHODS AND MATERIALS

Serial brain imaging scans were available for review in 25 of 34 patients with glioblastoma who underwent brain implant boost. Of 381 scans performed between the date of diagnosis and the date of death or last follow-up, 362 (95%) were re-reviewed. Disease progression was scored as local (within 2 cm of the implant site), separate within the brain parenchyma (> or = 2 cm from the implant site), subependymal, or systemic. Both initial and subsequent failures were scored.

RESULTS

Three patients are 5-year survivors, without evidence of disease, at 267, 292, and 308 weeks. Of the 22 initial sites of failure, 17 (77%) were local, three (14%) were separate brain lesions (one of which was due in retrospect to multicentric disease at diagnosis), one (5%) subependymal, and one (5%) systemic. Five patients with local failure later had other sites of failure, including a separate brain lesion in 1, subependymal spread in 3, and both in 1. One patient with separate brain failure later had local progression and then subependymal spread.

CONCLUSION

Although there was a significant risk of separate brain lesions or subependymal spread over time, local tumor progression was the predominant pattern of failure.

Long term results of stereotactic brachytherapy used in the initial treatment of patients with glioblastomas

BACKGROUND

Despite optimal therapy with surgery and radiotherapy, the prognosis of patients with glioblastomas remains poor. Stereotactic brachytherapy involves the accurate placement of radioactive isotopes within brain tumors, significantly increasing the dose of radiation that can be delivered to the tumor bed without substantial risk to surrounding normal tissue, potentially improving local tumor control and patient survival.

METHODS

Between February 1987 and July 1993, the authors treated 56 patients with glioblastomas with stereotactic brachytherapy as part of their initial therapy. Patients underwent surgery, limited field external beam radiotherapy, and brachytherapy with temporary high-activity iodine 125 sources, giving an additional 50 Gy to the tumor bed.

RESULTS

Median survival for patients undergoing brachytherapy was 18 months compared with 11 months for a matched brachytherapy control group with similar clinical and radiologic features (P < 0.0007). Survival rates at 1, 2, and 3 years after diagnosis of 83%, 34%, and 27%, respectively, for patients receiving brachytherapy were significantly increased compared with survival rates of 40%, 12.5%, and 9%, respectively, for control subjects. Thirty-six patients (64%) underwent reoperation for symptomatic radiation necrosis from 3 to 42 months (median, 11 months) after brachytherapy. The median survival of patients undergoing reoperation was 22 months compared with 13 months for those who did not have further surgery (P < 0.02). Thirty-five percent of patients relapsed locally within the brachytherapy target volume, whereas 65% had marginal or distant relapses.

CONCLUSIONS

Brachytherapy may improve local tumor control and prolong survival when used in the initial treatment of selected patients with glioblastomas.

Cortical localization of temporal lobe language sites in patients with gliomas

In a series of 40 patients undergoing an awake craniotomy for the removal of a glioma of the dominant hemisphere temporal lobe, cortical stimulation mapping was used to localize essential language sites. These sites were localized to distinct temporal lobe sectors and compared with 83 patients without tumors who had undergone language mapping for the treatment of intractable epilepsy. In patients with and without temporal lobe gliomas, the superior temporal gyrus contained significantly more language sites than the middle temporal gyrus. Both patient populations also had language sites anterior to the central sulcus in the superior temporal gyrus (12-16%). The patients without tumors had significantly more language sites in the superior temporal gyrus, compared with the superior temporal gyrus of patients with temporal lobe tumors. Multiple variables were studied for their effect on preoperative and postoperative language deficits and included age, sex, number of language sites, histology, size of the tumor, and the distance of tumor resection margins from the nearest language site. The distance of the resection margin from the nearest language site was the most important variable in determining the improvement in preoperative language deficits, the duration of postoperative language deficits, and whether the postoperative language deficits were permanent. If the distance of the resection margin from the nearest language site was > 1 cm, significantly fewer permanent language deficits occurred. Cortical stimulation mapping for the identification of essential language sites in patients with gliomas of the dominant hemisphere temporal lobe will maximize the extent of tumor resection and minimize permanent language deficits.

Efficacy of direct intratumoral therapy with targeted protein toxins for solid human gliomas in nude mice

Targeted protein toxins are a new class of reagents with the potential for great tumor selectivity and cytotoxic potency. Two such compounds were studied: 1) Tf-CRM107, a conjugate of human transferrin (Tf) and diphtheria toxin with a point mutation (CRM107); and 2) 454A12-rRA, a conjugate of a monoclonal antibody (454A12) to the human Tf receptor and recombinant ricin A chain (rRA). Both compounds are potent and specific in killing human glioblastoma cell lines in vitro. The authors investigated the activity of these reagents administered intratumorally against solid U251 MG human gliomas in vivo. Nude mice with established U251 MG flank tumors (0.5 to 1.0 cm in diameter) were randomly assigned to be treated with 100-microliters intratumoral injections of Tf-CRM107 (10 micrograms) or 454A12-rRA (10 micrograms), equimolar doses of CRM107 (4.3 micrograms), 454A12 antibody (7.5 micrograms), or rRA (1.5 micrograms), or phosphate-buffered saline (PBS) every 2 days for a total of four doses. Tumor volume and animal weight were assessed by a blinded observer before each treatment and biweekly for 30 days after initiating therapy. With Tf-CRM107 administration, tumor regression of greater than 95% occurred by Day 14 (p < 0.01) and tumors did not recur by Day 30. Treatment with 454A12-rRA caused a 30% decrease in tumor volume by Day 14 (p < 0.01). Treatment with equimolar doses of the unconjugated targeted protein toxin components CRM107, 454A12, or rRA caused significant U251 MG tumor growth inhibition, but the effects were less potent than the antitumor effects of the conjugates. This study also characterized the dose-response effect of Tf-CRM107 on tumor growth and tumor weight on Day 30. Nude mice with established U251 MG flank tumors (0.5 to 1.0 cm in diameter) were treated with 100-microliters intratumoral injections of 10, 1.0, or 0.1 microgram of Tf-CRM107 or PBS every 2 days for a total of four doses. All three doses of Tf-CRM107 significantly inhibited tumor growth by Day 14 (p < 0.01) and at Day 30 (p < 0.05), with a significant dose-response relationship. This study demonstrated in vivo efficacy of the targeted toxins Tf-CRM107 and 454A12-rRA against a human glioma. With intratumoral administration, the effect of Tf-CRM107 was tumor-specific and in some animals curative. Regional therapy with these potent tumor-specific agents using direct intratumoral infusion should limit systemic toxicity and may be efficacious against brain tumors.

Malignant glioma: patterns of failure following individually tailored limited volume irradiation

Treatment outcome was analyzed for 66 patients with malignant glioma treated with individually CT-planned multifield irradiation techniques. Total doses of 60 Gy were given, with the planning target volume (PTV) including 2 cm beyond the tumour indicated by preoperative CT examination. Median survival was 14 months, and 86% of recurrences occurred in the treated volume. Our results suggest that the used PTV and radiation technique should be appropriate in radiotherapy of malignant glioma.

Radiation therapy combined with radiosensitizing agents for cerebral glioblastoma in adults

We analyzed our treatment results of 71 operated patients with cerebral glioblastoma treated by conventional external radiation therapy (mean dose 60.2 Gy) combined with radiosensitizing agents. More than 50% reduction of tumor volume was obtained in 20 patients (28.2%). A response rate of at least 40% was obtained in patients treated with combined ACNU-vincristine-nicardipine, ACNU-5FU-hydroxyurea, or cisplatin alone. The combination of ACNU and vincristine with or without nicardipine resulted in significantly longer survival. The median survival in this group was 101.1 weeks and the two-year survival rate was 45.9%; these results were significantly better than those achieved with other ACNU combinations or other combinations without ACNU. In the analysis of survival, factors correlated to longer survival were a patient age of younger than 45 years, wide resection of the tumor, a good postoperative performance status (KS > or = 70%), a radiation dose of 68-72 Gy, small postoperative tumor remnants (< 20 cm3), no visible tumor after radiation therapy, and the administration of adjuvant chemotherapy. Maximum resection of the tumor and localized irradiation with a dose of 70 Gy combined with ACNU and vincristine appears to be the most effective treatment at present.

A comparison of survival between radiosurgery and stereotactic implants for malignant astrocytomas

The purpose of this paper is to compare the survival of three groups of patients with high grade supratentorial gliomas who were treated on three sequential protocols with surgical resection, external beam fractionated radiotherapy and a boost to the residual contrasting enhancing mass by either interstitial brachytherapy (IB, n = 33), by interstitial thermoradiotherapy (IT, n = 25) or by stereotactic radiosurgery (SRS, n = 19). The primary aim of this study was to evaluate the role of different boosting techniques in the initial management of primary brain tumors. External beam radiotherapy doses were escalated from one study to the next so that the median doses given to the IB, the IT, and the SRS groups were 41.4 Gy, 48.4 Gy, and 59.4 Gy, respectively. The median dose of interstitial irradiation or stereotactic radiosurgery, were 40 Gy, 32.2 Gy and 10 Gy, respectively, for the same groups. Follow-up was such that all living patients had been followed for a minimum of 30, 27, 4 months in the IB, IT, and SRS groups, respectively; hence, twelve-month survival was 52% (95% CI: 34%-69%), 80% (95% CI: 64%-96%), and 51% (95% CI: 24%-78%) in the same respective groups. Using a multivariate Cox proportional hazards model, treatment with IT conferred a survival advantage over IB (p = 0.029). Furthermore, survival of patients treated with SRS did not significantly differ from that of patients treated with an implant with or without hyperthermia.(ABSTRACT TRUNCATED AT 250 WORDS)

The basis for current treatment recommendations for malignant gliomas

Although primary brain tumors represent an important cause of cancer related mortality in the United States, advances in the treatment of these tumors has been slow and has generally lagged behind that of most systemic tumors. One of the major reasons for this is the paucity of well conducted, prospective radiation and chemotherapy trials. For the brain tumor trials that have been conducted, small patient numbers, heterogeneous patient populations, and non-uniformity of response criteria, have made the current clinical data base difficult to interpret. Data from several prospective, multi-institutional randomized trials have defined a role for radiation therapy in the treatment of malignant gliomas and on-going trials will help define refinements in technique. Although there does appear to be a place for the use of chemotherapy in the treatment of a subgroup of patients with malignant gliomas, its role for the majority of patients remains unclear. Only through better understanding of the biology of these tumors, more effective therapies, and the implementation of better clinical trial design can we hope to make significant progress in the treatment of malignant gliomas.

Early postoperative magnetic resonance imaging after resection of malignant glioma: objective evaluation of residual tumor and its influence on regrowth and prognosis

In the vast majority of studies that address the role of surgery in the management of high-grade gliomas, the degree of tumor removal accomplished is solely based on the intraoperative perception of the neurosurgeon. Despite its fundamental importance for a comparison of different treatment modalities, little systematic effort has been made to evaluate the residual gross tumor by neuroimaging methods immediately after surgery. We report the results of a prospective study using contrast-enhanced computed tomography and magnetic resonance imaging (MRI) to monitor 60 patients after the resection of a high-grade glioma. In each case, the first scans were obtained between Days 1 and 5 after surgery, followed by serial imaging every 2 to 3 months, usually until the condition of the patient deteriorated severely or the patient died. Gadolinium-enhanced MRI proved to be extremely valuable for assessing gross residual tumor when performed during Days 1 to 3 after the resection of a preoperatively enhancing high-grade glioma. This timing avoided surgically induced contrast enhancement and minimized interpretative difficulties. In delineating residual tumor, MRI was vastly superior to computed tomography. About 80% of tumor "recurrences" emerged from definitely enhancing remnants, as revealed by early postoperative MRI. The neurosurgeon's estimation of gross tumor burden reduction could be shown to be much less accurate (by a factor of 3) than the postoperative assessment by modern neuroimaging. In our series, residual tumor enhancement was the most predictive prognostic factor of survival in patients with glioblastoma, followed by radiotherapy. Patients with a residual tumor postoperatively had a 6.595-times higher risk of death in comparison to patients without a residual tumor. Patients undergoing radiotherapy had a 0.258-times lower risk of death in comparison to patients who were not treated with radiation. Concerning survival, the prognostic significance of both variables surpassed age and performance.

Radiosurgery/stereotactic external beam radiotherapy for malignant brain tumours: the Royal Marsden Hospital experience

SRT is a high-precision technique of radiotherapy which delivers focused irradiation to small target volumes. In the context of external beam radiotherapy it can be described as stereotactically guided conformal radiotherapy. As the technique originated from neurosurgical technology, it has initially been limited to single fraction treatment. However, with the use of relocatable fixation devices the way ahead particularly in its application in the treatment of brain tumours is in fractionated SRT. Currently, single fraction SRT/radiosurgery is of proven value only in the treatment of small inoperable arteriovenous malformations. It is being exploited in the management of brain tumours but so far remains as experimental treatment. We have demonstrated that fractionated SRT in patients with gliomas is a non-invasive equivalent to brachytherapy and in patients with solitary metastases a non-invasive alternative to surgical excision. However, the treatment is not without side effects, and the long-term effectiveness and toxicity of SRT, particularly with the use of unconventional fractionation, is not defined. The future use of SRT in the treatment of brain tumours should not be guided simply by the technical possibilities but by a rational appraisal of all treatment options to achieve the best disease control, survival and toxicity. Although there is potential for benefit in a number of small tumours, SRT cannot at present be recommended as the primary treatment in any tumour. In addition, its use should be discouraged in the treatment of unbiopsied brain lesions and as the major form of treatment of pineal germinomas. The technology of stereotactic radiotherapy is evolving, and it is likely that SRT will be integrated into conventional radiotherapy practice to become simply a high-precision technique of radiotherapy delivery in everyday use.

Detection of proliferating cell nuclear antigen in gliomas and adjacent resection margins

We describe a technique for estimating the number of proliferating cells in gliomas and adjacent resection cavities after tumor removal. Proliferating cell nuclear antigen (PCNA) is a nuclear protein associated with the cell cycle. Anti-PCNA antibody staining provides a semiquantitative estimate of the number of proliferating cells found in fixed tissue embedded in paraffin. The extent of the staining of tumor cells of glioblastoma multiforme, anaplastic astrocytomas, low-grade gliomas, and other lesions of the brain with anti-PCNA antibody is correlated with the histological diagnosis. In addition, the labeling of the margins after resection of gliomas and other lesions with anti-PCNA antibody is also associated with the histological diagnosis of the lesion. This technique may be useful in estimating the "biological" extent of resection and in predicting the recurrence patterns of gliomas.

Staging of supratentorial hemispheric glioma using tumour extension, histopathological grade and extent of surgical resection

A 'TGS' classification for supratentorial brain glioma is proposed, based on three parameters: tumour extension (T), histopathological grade (G) and extent of surgical resection (S). Two groups of patients were analysed: the first (n = 137) had tumour submitted to stereotactic biopsy; the second (n = 60) had malignant glioma operated on by craniotomy and tumor resection. All three staging parameters significantly influenced survival. Histopathological grade was the most significant factor, and the only independent variable on multivariate analysis, followed by extent of tumour and then extent of surgical resection. The data support the applicability of the proposed parameters for a staging classification of hemispheric brain glioma.

The chemotherapy of adult primary brain tumors

Adult patients with primary malignant brain tumors are a heterogeneous group. Most patients will have high-grade astrocytomas and can be expected to obtain minimal benefit from current standard chemotherapy regimens. Intra-arterial chemotherapy, high-dose chemotherapy with autologous bone marrow rescue, and new chemotherapeutic agents designed to penetrate the blood-brain barrier have not resulted in significant advances to date. However, there are exciting new directions in the chemotherapy of high-grade astrocytomas which are entering clinical trials. Two potentially promising approaches include interstitial chemotherapy using surgically implanted polymers and the continuous infusion of combinations of active chemotherapeutic agents. Other therapeutic modalities such as radioactive seed implants, stereotactic radiosurgery, and gene therapy are also being evaluated. Hopefully, this intense activity by subspecialists with a wide range of interests and expertise will produce novel and effective treatments for the large number of patients with malignant astrocytomas. In contrast, patients with many of the less common neoplasms of the central nervous system may benefit from the addition of chemotherapy to their treatment. Primary germ cell tumors or lymphomas of the central nervous system are very sensitive to chemotherapy. The germ cell tumors respond to the cisplatin-containing regimens developed for testicular malignancies. The optimal chemotherapy for CNS lymphoma is not clear but exciting results have been reported with a combination of radiation, systemic and intrathecal methotrexate, and systemic cytosine arabinoside. Although limited, the available literature suggests that patients with anaplastic oligodendrogliomas may also benefit from chemotherapy at diagnosis or at relapse. Studies in children suggest a benefit for adjuvant chemotherapy and radiation therapy in poor risk patients with medulloblastomas although these findings have not been confirmed in adults. Finally, anecdotal reports suggest that chemotherapy may be useful in the very rare patient who presents with a pineal tumor or an ependymoma.

High dose hyperfractionated radiotherapy for adults with glioblastomas

From 1989 to 1991, 27 patients with glioblastoma multiforme or anaplastic astrocytoma of the brain were treated with radiotherapy. Fifteen of twenty-seven patients were treated through limited volume fields, with a thrice-a-day (1.1 Gy/f) or twice-a-day (1.4 Gy/f) hyperfractionated regimen to a total physical dose of 62-92 Gy (median dose 76 Gy). The remaining 12 were treated with whole brain irradiation (40 Gy of total conventionally fractionated dose) and a localised boost to a total dose of 60 Gy. The hyperfractionated regimen was well tolerated and there was no sign of increased brain oedema to indicate the insertion of a split. Of six patients who received a NTD10 (normalised total dose for alpha/beta = 10) higher than 71 Gy, five showed CR (83% CR rate) versus three of 21 patients who received a lower NTD10 (14% CR rate). For 13 patients who received a NTD10 higher than 66 Gy, the 18-months survival was 61% (8/13) versus 28% (4/14) for 14 patients who received a NTD10 less than 66 Gy. As far as the late morbidity is concerned, of six patients treated with 76-92 Gy of physical dose, none died because of radiation-induced brain necrosis within 18-42 months of follow-up, and three of them are without evidence of disease 18-31 months after the end of radiation treatment. None of our 15 patients who received less than whole brain irradiation relapsed outside the radiation portals. The present study strongly suggests the use of limited volume hyperfractionated radiotherapy schemes, so as to increase the local tumor dose (NTD10) to values higher than 79 Gy, at the same time keeping the NTD2 (NTD for alpha/beta = 2) below 68 Gy.

Detection of recurrent gliomas with quantitative thallium-201/technetium-99m HMPAO single-photon emission computerized tomography

Deteriorating clinical status after high-dose radiation therapy for high-grade gliomas may be due to radiation changes or may signal recurrent or residual tumor mass. The two conditions cannot be distinguished reliably by computerized tomography (CT) or magnetic resonance (MR) imaging. The authors assessed the ability of sequential thallium-201 chloride (201Tl) and technetium-99m hexamethylpropylene amine oxime (99mTc HMPAO) single-photon emission CT (SPECT) to distinguish tumor recurrence from radiation changes after high-dose (greater than or equal to 600 cGy) radiation therapy for malignant gliomas. Preoperative tumor/nontumor uptake ratios were analyzed in 32 patients and correlated with the presence of gross tumor at the time of reoperation. In 12 of 13 patients with 201Tl tumor/scalp ratios of 3.5 or greater, recurrent tumor was present. The authors found 99mTc HMPAO SPECT to be useful for identifying the absence of solid tumor recurrence in patients with low to moderate 201Tl uptake (ratio 1.1 to 3.4) and low perfusion to that site. In 11 of 12 patients with 99mTc HMPAO tumor/cerebellum ratios of 0.50 or less, no recurrent tumor mass was present. Three of seven patients with 201Tl ratios of 3.4 or less and 99mTc HMPAO ratios of 0.51 or more had recurrent tumor found at surgery; thus the test was not predictive in this group. It is concluded that the use of sequential 201Tl and 99mTc HMPAO SPECT accurately identifies the presence of tumor recurrence versus radiation changes in most patients with high-grade astrocytomas who have undergone tumor resection and high-dose radiation therapy.

Biology and treatment of gliomas

This review discusses some of the recent advances in glioma research and treatment. Our understanding of the characteristics of these tumors has been strengthened by the application of molecular biologic and genetic techniques to pathologic grading and therapy outcome. Newer attempts to correlate imaging modalities to pathologic grading are also discussed. It is anticipated that these developments will strengthen our ability to design improved treatment strategies, an essential goal inasmuch as current treatment schemes have limited benefit. More work needs to be done to understand the biology of these tumors especially the complex interactions of their cytokine expression, multiplicity of genetic abnormalities, and their local environment. Only then will be able to develop improved therapeutic interventions.

A Comparison of CT Contrast Enhancement and BUDR Labeling Indices in Moderately and Highly Anaplastic Astrocytomas of the Cerebral Hemispheres

Contrast enhancement on computerized tomography (CT) scans has been used in directing therapy for presumed intracranial gliomas. However, for moderately anaplastic astrocytomas (MOAAS) and highly anaplastic astrocytomas (HAAS), it provides no information about proliferative potential. The bromodeoxyuridine (BUDR) labeling index (LI), however, indicates proliferative potential, correlating with histologic malignancy and survival. An LI < 1% is a favorable indicator; LI > 5% suggests more aggressiveness. To determine the correlation, if any, between BUDR LI and contrast enhancement, CT scans of 71 patients with cerebral hemisphere tumors labeled with BUDR were retrospectively reviewed. Among 36 MOAAS, the BUDR LI was < 1% in 77% of enhanced tumors and 61% of unenhanced tumors. Among 35 HAAS, it was < 5% in 56% of enhanced tumors and 90% of unenhanced tumors. Therefore, contrast enhancement on CT scans does not always correctly predict proliferative potential in these tumors, and biopsy and labeling studies are recommended before therapy.

Vertex field verification in the treatment of central nervous system neoplasms

Increasing sophistication of computerized brain tumor treatment plans has enabled clinicians to devise increasingly complex field combinations to spare as much normal brain tissue as possible. These treatment plans often call for the use of a vertex field. This report describes a simple, useful technique for the verification of the vertex (or any non-coplanar) field on the treatment machine--a procedure that is impossible with conventional port film techniques.

Treatment of malignant gliomas with interstitial irradiation and hyperthermia

A Phase I study of interstitial thermoradiotherapy for high-grade supratentorial gliomas has been completed. The objective of this trial was to test the feasibility and toxicity of hyperthermia induced by ferromagnetic implants in the treatment of intracranial tumors. The patient population consisted of 16 males and 12 females, with a median age of 44 years and a median Karnofsky score of 90. Nine patients had anaplastic astrocytoma while 19 had glioblastoma multiforme. Twenty two patients were treated at the time of their initial diagnosis with a course of external beam radiotherapy (median dose 48.4 Gy) followed by an interstitial implant with Ir-192 (median dose 32.7 Gy). Six patients with recurrent tumors received only an interstitial implant (median dose 40 Gy). Median implant volume for all patients was 55.8 cc and median number of treatment catheters implanted per tumor was eighteen. A 60-minute hyperthermia treatment was given through these catheters just before and right after completion of brachytherapy. Time-averaged temperatures of all treatments were computed for sensors located within the core of (> 5 mm from edge of implant), and at the periphery of the implant (outer 5 mm). The percentage of sensors achieving an average temperature > 42 degrees C was 61% and 35%, respectively. Hyperthermia was generally well tolerated; however, there have been 11 minor toxicities, which resolved with conservative management, and one episode of massive edema resulting in the death of a patient. In addition, there were three major complications associated with the surgical implantation of the catheters. Preliminary survival analysis shows that 16 of the 28 patients have died, with a median survival of 20.6 months from diagnosis. We conclude that interstitial hyperthermia of brain tumors with ferromagnetic implants is feasible and carries significant but acceptable morbidity given the extremely poor prognosis of this patient population.

Patterns of recurrence of malignant astrocytoma following stereotactic interstitial brachytherapy with iodine-125 implants

The pattern of tumor recurrence was studied in a series of 68 patients who were treated with interstitial brachytherapy for malignant astrocytoma. Thirty-six patients had newly diagnosed tumors and were treated following surgery and external beam therapy, while 32 were treated for recurrent tumors. Recurrence pattern was determined using computed tomography at the time of clinical deterioration. Thirty-eight percent of tumor recurrence occurred within the original tumor margin and 50% occurred at the original site but extended beyond the initial margin. In all, 88.0% recurred at the initial tumor site, 71.4% being confined to within 2 cm of the pretreatment tumor borders while 6.0% recurred intracranially outside of the initial tumor margin. One patient recurred with spinal metastasis while two patients developed systemic metastases. The significance of these findings is discussed.

Interstitial brachytherapy for newly diagnosed patients with malignant gliomas: the UCSF experience

Although interstitial brachytherapy appears to be effective in treating recurrent malignant gliomas, it has been studied less extensively in patients with newly diagnosed tumors. To examine the effect of this treatment when used at the time of primary diagnosis, we retrospectively reviewed the records of 88 patients who received temporary interstitial implants of 125I for newly diagnosed malignant gliomas. This brachytherapy was preceded by a course of external radiation therapy and followed, in some cases, by chemotherapy. The median duration of survival after the beginning of external radiation therapy was 87 weeks in patients with glioblastoma multiforme and 160 weeks in those with anaplastic gliomas. In 46% of patients with glioblastoma multiforme and 56% of those with anaplastic gliomas, a second operation was necessary to remove symptomatic radiation necrosis, recurrent tumor, or both. Our results support the conclusion that interstitial brachytherapy used at the primary diagnosis lengthens survival in selected patients with glioblastoma multiforme. However, the toxicity is significant in terms of the need for surgical resection of symptomatic necrosis. In patients with anaplastic gliomas, the toxicity associated with the treatment probably outweighs its advantages.

Thermoradiotherapy of recurrent malignant brain tumors

In an attempt to improve local control and survival over those achieved with brain implant alone, a Phase I/II study of interstitial thermoradiotherapy was undertaken for recurrent malignant gliomas and recurrent solitary brain metastases. Between June 1987 and September 1990, 49 tumors in 48 patients were treated with thermoradiotherapy, including 26 glioblastoma multiforme (GM), 16 anaplastic astrocytomas (AA), 4 adenocarcinomas, and 3 melanomas. Patient age ranged from 18 to 71 years and Karnofsky Performance Status from 40 to 90. Stereotactically implanted catheters were used for both hyperthermia and brachytherapy. Hyperthermia was administered immediately before and after brachytherapy, heating as much of the tumor as possible to 42.5 degrees C for 30 min using helical coil microwave antennas. High-activity iodine-125 sources delivered tumor doses of 32.6 to 63.3 Gy. Complications included reversible neurologic changes in 13 patients, 9 seizures, 4 infections, 1 deep venous thrombosis with pulmonary embolus, and 1 scalp burn. Eighteen patients underwent reoperation for tumor and/or necrosis. Follow-up ranged from 9 to 166+ weeks. The median follow-up for living patients with GM and AA was 37 weeks and 92 weeks, respectively. Actuarial median survival was 47 weeks for patients with GM. For patients with AA, actuarial survival was 65% at 18 months and median survival has not yet been reached. Multivariate analysis showed a strong correlation between freedom from local tumor progression and "T90" temperature or minimum tumor temperature. Interstitial brain thermoradiotherapy is now being evaluated in a randomized Phase II trial for previously untreated GM.

Stereotactic brachytherapy for malignant glioma using a relocatable frame

Interstitial brachytherapy for recurrent gliomas normally necessitates the invasive application of a stereotactic frame by screw-fixation which must be kept on for several hours. The use of a relocatable stereotactic frame offers many advantages over conventional systems. We present our experience in 18 patients and verify that the frame used is accurate, comfortable, well tolerated and associated with no major disadvantages.

Role for proton beam irradiation in treatment of pediatric CNS malignancies

The ability to vary the proton energy (depth of beam penetration) and modulate the dose distribution at the end of range permits delivery of an increased dose to the designated cancer-containing volume with a reduced dose to overlying normal brain tissue. The evolution of childhood CNS malignancy following therapy is reviewed to identify radiation response variables indicating where the proton dose distribution will improve the therapeutic ratio. The review documents that of the 1262 children expected to develop CNS malignancy in 1989, only 43% will survive 5 years. About 75% of those with medulloblastoma and over 90% with astrocytoma die from persistent (in-field) disease. When the patient has been treated with radiation, it is accepted that disease persistence indicates the cancer dose was insufficient. Potentially 536 children could show an improved incidence of local control and improved survival from an increased cancer dose available from proton irradiation. As the total dose and volume of brain irradiated is increased about 1800 cGy, brain dysfunction increases, producing a spectrum of functional and intellectual deficits which are age and volume related. About 900 irradiated patients would have fewer in-field histologic and functional changes if the dose to normal brain, or the volume of brain irradiated, is reduced by an improved dose distribution. A proton beam treatment plan, delivering a cancer dose of 7400 cGy, is simulated for a thalamic astrocytoma. The dose distribution of this plan is compared with an x-ray plan used to treat a patient, in which a dose of 5400 cGy was delivered to the astrocytoma. Comparative isodose distributions and dose-volume histograms indicate a decreased integral dose to normal brain and a decreased volume of normal brain irradiated, even as the cancer dose is boosted 2000 cGy with protons.

High activity iodine-125 interstitial implant for gliomas

A total of 307 adult patients with glioma were treated with high-activity removable iodine-125 interstitial brain implants at the University of California at San Francisco from December 1979 to June 1990. Recurrent gliomas underwent brain implant alone whereas previously untreated (primary) tumors underwent brain implant boost after external beam radiotherapy. Of these patients, 106 had primary glioblastoma multiforme, 68 had primary non-glioblastoma glioma, 66 had recurrent glioblastoma multiforme and 67 had recurrent nonglioblastoma glioma. Median follow-up for living patients was 143 weeks. Median survival from diagnosis for primary glioblastoma multiforme and high and low grade nonglioblastoma glioma was 88 weeks, 142 weeks, and 226 weeks, respectively. Median survival measured from the date of implant for recurrent glioblastoma multiforme and high and low grade nonglioblastoma glioma was 49 weeks, 52 weeks, and 81 weeks, respectively. Ninety-two percent of patients had no toxicity or transient acute side effects. Severe acute toxicity was seen in 6% of patients, life threatening acute toxicity in 1% of patients, and fatal toxicity in less than 1% of patients. Forty percent of patients with malignant glioma underwent reoperation at a median of 33 weeks after brain implant, with tumor found in 95% of specimens at reoperation. This large experience demonstrates that interstitial implant is well-tolerated and prolongs survival in patients with primary and recurrent glioblastoma multiforme, as evidenced by the 3-year survival rates of 22% and 15%, respectively.