Patterns of failure following treatment for glioblastoma multiforme and anaplastic astrocytoma

A Medical Research Council trial of two radiotherapy doses in the treatment of grades 3 and 4 astrocytoma. The Medical Research Council Brain Tumour Working Party

A total of 474 adult patients with malignant glioma (astrocytoma) grade 3 or 4 were randomised into an MRC study (BR2) comparing 45 Gy (in 20 fractions over 4 weeks) with 60 Gy (in 30 fractions over 6 weeks) of radiotherapy given post-operatively. Using 2:1 randomisation, 318 patients were allocated the 60 Gy course and 156 the 45 Gy course. Adjuvant chemotherapy was not given. The results show that a 60 Gy course produces a modest lengthening of progression-free and overall survival. They suggest a statistically significant prolongation of median survival from 9 months in the 45 Gy group to 12 months in the 60 Gy group (hazard ratio = 0.75, chi 2 = 7.36, d.f. = 1, P = 0.007). Over 80% of patients reported no morbidity from the radiotherapy, and there was no evidence of increased short-term morbidity in the higher dose group. Late morbidity was not assessed. A prognostic index defined in a previous MRC study was validated in this new cohort. It identifies a group of patients (20% of the total) with a 2 year survival rate of 28% (95% confidence interval 19% to 38%). It was apparent that the survival advantage to the higher dose was maintained even in the poorest prognostic groups defined by this index.

Malignant astrocytomas: focal tumor recurrence after focal external beam radiation therapy

Hochberg and Pruitt have reported glioblastomas recurring within 2 cm of the primary site in 90% of patients after whole-brain radiation therapy. They suggested that computerized tomography (CT) scan accuracy would permit smaller radiation fields. A treatment protocol with smaller-field focal brain irradiation following surgical resection is reported. The first 4500 cGy of radiation is focused to within a 3-cm margin around the tumor, with a 1500-cGy boost within a 1.5-cm margin. Forty-two patients with grade III or IV astrocytoma, treated with focal brain radiation therapy were reviewed retrospectively to assess patterns of tumor recurrence. Thirty patients received intra-arterial bromodeoxyuridine (BUdR) radiosensitization with focal brain radiation therapy, and 12 patients underwent conventional focal brain radiation therapy. Tumor margin was defined on preoperative and recurrence CT scans as the contrast-enhanced area; these were traced on acetate templates and compared with each other and with the actual scans. In all 42 patients, the lesion recurred within a 2-cm margin of the original tumor. Four patients had two recurrent areas: the second area was within the 2-cm margin in two, and outside this margin in two. These results are similar to those of Hochberg and Pruitt. It is suggested that focal irradiation is now the optimal treatment for malignant astrocytoma. Since recurrences continue to be within the irradiated volumes, it appears that higher focal doses of radiation are appropriate for clinical treatment trials of malignant astrocytomas.

Radiation in the treatment of high grade malignant gliomas in Queensland

Two hundred and seventy eight patients with histologically proven grade 3 or grade 4 astrocytomas were referred to the Queensland Radium Institute for consideration of radiotherapy between January 1980 and December 1987. The role of radiation in the management of these tumours was examined with respect to the effects of field size, dose and age. It was found that field size did not have a significant effect on survival; in particular whole brain irradiation for patients with grade 4 tumours was not a significant advantage. The doses used at the Queensland Radium Institute produce similar survivals to those used in other centres. The effect of age was significant. For grade 3 tumours there was a survival advantage to those under 50 years receiving radiation, but not to those above that age. For grade 4 tumours, the survival advantage was for those under 60 years, but those over 60 years did seem to get some benefit although the difference did not reach significance. It is suggested that, as the tumour is generally incurable, these patients may be better served by a short simple palliative course of radiation.

External irradiation followed by an interstitial high activity iodine-125 implant "boost" in the initial treatment of malignant gliomas: NCOG study 6G-82-2

Between January 1982 and January 1990, 107 patients with unifocal, circumscribed malignant gliomas participated 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 procarbazine, 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 implants, 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 implants, 67 weeks for all evaluable glioblastoma patients, and 88 weeks for those with implants. Of the glioblastoma 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 dependency, and increasing mass effect at the implantation site after 46.1 weeks (median) for glioblastoma multiforme 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 gliomas 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 60-100%) 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 glioblastoma multiforme but not for those with non-glioblastoma anaplastic gliomas.

Three-dimensional treatment planning of astrocytomas: a dosimetric study of cerebral irradiation

To demonstrate that 3-dimensional planning is both practical and applicable to the treatment of high-grade astrocytomas, 50 patients over a 2-year period have received cerebral irradiation delivered in focussed, non-axial techniques employing from 2 to 5 beams. Astrocytomas have been planned using rapid, practical incorporation of CT data to define appropriate tumor volumes. Tumor + 3.0 cm and tumor + 1.5 cm volumes have been treated to conventional doses of 4500 cGy and 5940 cGy, respectively, using beam orientations that maximally spared normal remaining parenchyma. Analyses of 3-dimensionally calculated plans have been performed using integral dose-volume histograms (DVH) to help select treatment techniques. Using identical CT-based volumetric data as input for generation of Beam's Eye View (BEV) designed blocks, DVH curves demonstrate dosimetric advantages of non-axial techniques over conventional parallel-opposed orientations. Assessment of the non-axial techniques in selected cases indicates that uniform target volume coverage could be maintained with a typical reduction of 30% in the total amount of brain tissue treated to high dose (95% isodose line).

Imaging of adult central nervous system primary malignant gliomas. Staging and follow-up

A classification and staging system for primary adult gliomas was proposed. This system uses the high signal intensity found on proton density or T2-weighted magnetic resonance (MR) scans at the site of the tumor and surrounding edema (including infiltrating tumor).

Interstitial thermoradiotherapy of brain tumors: preliminary results of a phase I clinical trial

A Phase I clinical trial has been initiated to determine the feasibility, tolerance, and toxicity of interstitial thermoradiotherapy in the treatment of high-grade supratentorial brain gliomas. Hyperthermia was delivered by means of thermally-regulating ferromagnetic implants afterloaded into stereotactically placed plastic catheters. Heat treatments were given immediately before interstitial irradiation; in addition, five patients received a second heat treatment at the completion of brachytherapy. The desired target temperature for the 60-minute hyperthermia session was between 42 degrees C and 45 degrees C. Following hyperthermia, the catheters were afterloaded with Ir-192, which delivered a variable radiation dose of 14-50 Gy depending on the clinical situation. Interstitial irradiation was supplemented with external beam radiotherapy (40-41.4 Gy) in patients with previously untreated tumors. A total of 14 patients (4 males, 10 females) have been treated to date on this protocol. Eleven of the patients had a diagnosis of glioblastoma multiforme, whereas three had anaplastic astrocytoma. The mean implant volume was 61.5 cm3 (range: 9-119 cm3); the median number of interstitial treatment catheters implanted was 19 (range: 7-33). Continuous temperature monitoring was performed by means of multisensor thermocouple probes inserted in the center as well as in the periphery of the tumor. Of the 175 monitored intratumoral points, 83 (47%) had time-averaged mean temperatures of greater than 42 degrees C, and only 12 sensors (7%) exceeded a temperature of 45 degrees C. Among the 19 heat treatments attempted, there have been four minor acute toxicities, all of which resolved with conservative medical management and one major complication resulting in the demise of a patient. These preliminary results indicate that ferromagnetic implants offer a promising new approach to treating brain tumors with hyperthermia.

A phase I/II study of the use of Fluosol as an adjuvant to radiation therapy in the treatment of primary high-grade brain tumors

The main objective of this study was to evaluate the safety and efficacy of a perfluorochemical emulsion, Fluosol, with short-term high inspired oxygen tension as an adjuvant to radiation therapy in the treatment of high-grade tumors of the brain. Radiation was delivered to the whole brain at 1.8 Gy per daily treatment for 5 weeks to a total dose of 45 Gy. The radiation portals were then reduced in size to encompass the known volume of tumor, as determined by the presurgical contrast-enhancing ring on computed tomography (CT), plus a 3-cm margin. An additional 10 treatments of 2 Gy each were given to the smaller volume, to bring the total tumor dose to 65 Gy in 7 weeks. This report describes the experience of the first 18 patients treated at the University of Kansas Medical Center on this study, whose median follow-up time from the date of surgery is 77 weeks (62-115 w). Immediately following Fluosol administration on a Monday, patients breathed 100% oxygen for at least 45 minutes prior to and throughout their radiation treatment. On each subsequent day of the weeks in which they received Fluosol, patients breathed 100% oxygen. Hematology and blood chemistries were also drawn prior to Fluosol treatment each Friday during treatment and at the 2-week, 3-month, and 6-month follow-up visits. The median age of the patients was 45 years (16-72); 13 patients were male and 15 carried the diagnosis of glioblastoma multiforme (3 had anaplastic astrocytoma). Two thirds of the patients had an initial allergic reaction to the Fluosol consisting of back pain, shortness of breath, and flushing, but all responded to 50-100 mg of Benadryl. During radiation therapy, all patients developed scalp erythema and complete alopecia by the end of 3 weeks, but no patient required a treatment rest. The serum levels of SGOT, SGPT, and alkaline phosphatase were examined before and throughout the Fluosol treatment and, by week 5, 11/18 of the patients had increased values of all three enzymes above the upper range of normal. These increases persisted through the end of treatment, but most values returned to essentially normal by the 3-month follow-up visit. We conclude that Fluosol, given in the manner described above, appears to be associated with minimal significant side effects and no changes could be detected in the white matter of any of the patients at the time of their magnetic resonance imaging study at 6 months follow-up.(ABSTRACT TRUNCATED AT 400 WORDS)

Patterns of second recurrence of malignant astrocytomas

CT scans of 12 patients who underwent resection of recurrent malignant astrocytoma and who had a radiographically documented second tumor recurrence were studied. Second tumor recurrence was histologically verified in four patients. Eight of 12 second recurrences were no more than 2.0 cm from the contrast-enhancing margin of the first recurrence. The remaining four patients had tumor recurrence within 2.2, 4.6, 5.1 and 6.9 cm of the enhancing margin of the first tumor recurrence. Peritumoral edema at the time of initial recurrence had no relationship to the patterns of second recurrence. It is concluded that patients who undergo reoperation for recurrent malignant astrocytoma are still primarily at risk for local tumor failure, as opposed to diffuse dissemination of disease throughout the brain.

Stereotaxic irradiation of brain tumors

Stereotaxic techniques may be used in combination with interstitial or external beam radiotherapy for the treatment of intracranial malignancies. At the University of California, San Francisco, temporary, high-activity, iodine 125 sources are used mainly for the treatment of malignant gliomas. Patients with unifocal lesions that are smaller than 5 to 6 cm have discrete margins on computed tomography (CT) limited to supratentorial regions are selected for stereotaxic implantation. Both primary and recurrent malignant gliomas are treated with stereotaxic implantation; primary malignant gliomas are treated in addition with nonstereotaxic external beam radiotherapy and concomitant and sequential chemotherapy. Median survival times measured from the time of implantation are as follows: primary glioblastoma multiforme, 95 weeks; recurrent glioblastoma multiforme, 54 weeks; primary anaplastic astrocytoma, 223 weeks; and recurrent anaplastic astrocytoma, 81 weeks. Stereotaxic interstitial brachytherapy in conjunction with hyperthermia (thermoradiotherapy) is being studied in the treatment of recurrent or metastatic intracranial malignancy. External beam radiotherapy delivered stereotaxically in a single fraction (radiosurgery) has been used mainly for benign intracranial processes, although several centers are now exploring its use in the management of highly selected malignant lesions. Although its role is not yet completely defined, it may prove useful in highly selected subsets of patients with small intracranial malignancies, whether primary, recurrent, or metastatic.

Survival and quality of life after interstitial implantation of removable high-activity iodine-125 sources for the treatment of patients with recurrent malignant gliomas

Between January 1980 and January 1988, 95 evaluable patients with recurrent, unifocal, supratentorial malignant gliomas were reirradiated with high-activity iodine-125 sources implanted directly into tumor in afterloaded, removable catheters using computerized tomography-directed stereotaxy. A tumor dose of 5270-15,000 cGy was delivered at a maximum distance of 0.5 cm from the rim of the contrast-enhancing mass seen on CT scans. The median survival for the 50 patients with anaplastic astrocytoma was 81 weeks and for 45 patients with glioblastoma multiforme it was 54 weeks. The 18- and 36-month survival rates for patients with anaplastic astrocytoma were 46% and 28%, respectively; the 18- and 36-month survival rates for patients with glioblastoma multiforme were 22% and 8%, respectively. Because of clinical deterioration, increasing steroid dependency, and increasing mass effect at the implantation site seen on CT scans, necrotic tissue was excised from 47 patients (49%) at craniotomy; in some patients, tumor was mixed with necrotic tissue. The survival of reoperated patients was significantly longer compared with patients who did not undergo this procedure. Serial determination of the Karnofsky Performance Score (KPS) showed that there was no significant deterioration for the group as a whole during the 6 months immediately after implantation. At 18 months, 33 of the patients were alive; KPS ranged between 50 to 90 (mean 79) and 67% were steroid dependent. At 36 months, 18 patients were alive; 17 patients were evaluable with KPS that ranged between 40 to 90 (mean 76) and 53% were steroid dependent. Eleven of the 17 evaluable long-term survivors had a KPS of 80 or higher with a mean of 87. Interstitial brachytherapy may provide long-term survival in selected patients with recurrent malignant gliomas who have been irradiated previously with conventional teletherapy. The quality of life in the majority of long-term survivors appears to be quite satisfactory. Further attempts to control tumor growth using this modality appear to be warranted.