Search

Purpose: Improved efficacy of anticancer therapy and a growing pool of survivors give rise to a question about their quality of life and return to premorbid status. Radiation is effective in brain metastasis eradication, although the optimal approach and long-term effects on brain function are largely unknown. We studied the effects of radiosurgery on brain function., Methods and Materials: Adult C57BL/6J mice with or without brain metastases (rat 9L gliosarcoma) were treated with cone beam single-arc stereotactic radiosurgery (SRS; 40 Gy). Tumor growth was monitored using bioluminescence, whereas longitudinal magnetic resonance imaging, behavioral studies, and histologic analysis were performed to evaluate brain response to the treatment for up to 18 months., Results: Stereotactic radiosurgery (SRS) resulted in 9L metastases eradication within 4 weeks with subsequent long-term survival of all treated animals, whereas all nontreated animals succumbed to the brain tumor. Behavioral impairment, as measured with a recognition memory test, was observed earlier in mice subjected to radiosurgery of tumors (6 weeks) in comparison to SRS of healthy brain tissue (10 weeks). Notably, the deficit resolved by 18 weeks only in mice not bearing a tumor, whereas tumor eradication was complicated by the persistent cognitive deficits. In addition, the results of magnetic resonance imaging were unremarkable in both groups, and histopathology revealed changes. SRS-induced tumor eradication triggered long-lasting and exacerbated neuroinflammatory response. No demyelination, neuronal loss, or hemorrhage was detected in any of the groups., Conclusions: Tumor disintegration by SRS leads to exacerbated neuroinflammation and persistent cognitive deficits; therefore, methods aiming at reducing inflammation after tumor eradication or other therapeutic methods should be sought., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Synchrotron facilities produce ultra-high dose rate X-rays that can be used for selective cancer treatment when combined with micron-sized beams. Synchrotron microbeam radiation therapy (MRT) has been shown to inhibit cancer growth in small animals, whilst preserving healthy tissue function. However, the underlying mechanisms that produce successful MRT outcomes are not well understood, either in vitro or in vivo. This study provides new insights into the relationships between dosimetry, radiation transport simulations, in vitro cell response, and pre-clinical brain cancer survival using intracerebral gliosarcoma (9LGS) bearing rats. As part of this ground-breaking research, a new image-guided MRT technique was implemented for accurate tumor targeting combined with a pioneering assessment of tumor dose-coverage; an essential parameter for clinical radiotherapy. Based on the results of our study, we can now (for the first time) present clear and reproducible relationships between the in vitro cell response, tumor dose-volume coverage and survival post MRT irradiation of an aggressive and radioresistant brain cancer in a rodent model. Our innovative and interdisciplinary approach is illustrated by the results of the first long-term MRT pre-clinical trial in Australia. Implementing personalized synchrotron MRT for brain cancer treatment will advance this international research effort towards clinical trials.

The current methodology for determining the biological effect of Boron Neutron Capture Therapy (BNCT) has recently been questioned, and a more accurate framework based in the photon iso-effective dose has been proposed. In this work we derive a first order approximation to this quantity. The new approach removes the main drawbacks of the current method, being based on new weighting factors which are true constants (dose independent) but which can be evaluated from published data on the existing (dose-dependent) weighting factors. In addition to this, we apply the formalism to allow the comparison to a fractionated conventional radiotherapy treatment, for which there is a lot of knowledge from clinical practice. As an application, the photon iso-effective dose of a BNCT treatment for a brain tumor is estimated. An excel sheet used for these calculations is also provided as supplementary material and can be used also with user-provided input data for the estimation of the photon iso-effective dose for comparison with conventional radiotherapy, both to single and fractionated treatments., Competing Interests: Declaration of competing interest The authors declare no conflict of interest for this work., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Microbeam Radiation Therapy (MRT) exploits tumour selectivity and normal tissue sparing with spatially fractionated kilovoltage X-ray microbeams through the dose volume effect. Experimental measurements with Ta 2 O 5 nanoparticles (NPs) in 9L gliosarcoma treated with MRT at the Australian Synchrotron, increased the treatment efficiency. Ta 2 O 5 NPs were observed to form shells around cell nuclei which may be the reason for their efficiency in MRT. In this article, our experimental observation of NP shell formation is the basis of a Geant4 radiation transport study to characterise dose enhancement by Ta 2 O 5 NPs in MRT. Our study showed that NP shells enhance the physical dose depending microbeam energy and their location relative to a single microbeam. For monochromatic microbeam energies below ∼70keV, NP shells show highly localised dose enhancement due to the short range of associated secondary electrons. Low microbeam energies indicate better targeted treatment by allowing higher microbeam doses to be administered to tumours and better exploit the spatial fractionation related selectivity observed with MRT. For microbeam energies above ∼100keV, NP shells extend the physical dose enhancement due to longer-range secondary electrons. Again, with NPs selectively internalised, the local effectiveness of MRT is expected to increase in the tumour. Dose enhancement produced by the shell aggregate varied more significantly in the cell population, depending on its location, when compared to a homogeneous NP distribution. These combined simulation and experimental data provide first evidence for optimising MRT through the incorporation of newly observed Ta 2 O 5 NP distributions within 9L cancer cells., (Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

We recently developed the synthesis of ultrasmall gadolinium-based nanoparticles (GBN), (hydrodynamic diameter <5 nm) characterized by a safe behavior after intravenous injection (renal clearance, preferential accumulation in tumors). Owing to the presence of gadolinium ions, GBN can be used as contrast agents for magnetic resonance imaging (MRI) and as radiosensitizers. The attempt to determine the most opportune delay between the intravenous injection of GBN and the irradiation showed that a very low content of radiosensitizing nanoparticles in the tumor area is sufficient (0.1 μg/g of particles, i.e. 15 ppb of gadolinium) for an important increase of the therapeutic effect of irradiation. Such a promising and unexpected result is assigned to a suited distribution of GBN within the tumor, as revealed by the X-ray fluorescence (XRF) maps.

Purpose: Primary pediatric gliosarcoma (pPGS) is an extremely rare entity with only 25 cases reported in the English literature. The value of concurrent and adjuvant temozolomide is not known in this group of patient., Methods: Five patients of pPGS treated from 2006 to 2011 were included in this retrospective analysis. All patients underwent maximal safe surgical resection. Adjuvant therapy included conformal radiation 60 Gy in 30 fractions (2 Gy daily for 5 days in a week) with concurrent temozolomide 75 mg/m(2) daily followed by six cycles of maintenance temozolomide 150-200 mg/m(2) (day 1 to day 5) every 4 weeks. We combined the survival data of 25 patients (already published) and five of our patients and analyzed them in terms of progression free survival (PFS) and overall survival (OS) using Kaplan-Meier method., Results: Male to female ratio was 1:4 and median age was 12 years (range, 7-19 years). All but one patient underwent gross total resection and four patients completed adjuvant radiotherapy as well as concurrent and adjuvant temozolomide. At a median follow up of 22.6 months (range, 0 to 45.3 months), two patients were dead and two were alive without disease while one was lost to follow up. For the pooled data, estimated median PFS and OS of all 30 patients reported in literature were 12 and 43 months, respectively. Two years PFS and OS rate for all patients was 44.2 and 62.9%, respectively., Conclusion: Adjuvant radiotherapy and temozolomide is well tolerated and show an encouraging survival in pPGS.

Purpose: Synchrotron microbeam radiation therapy (MRT) is an innovative irradiation modality based on spatial fractionation of a high-dose X-ray beam into lattices of microbeams. The increase in lifespan of brain tumor-bearing rats is associated with vascular damage but the physiological consequences of MRT on blood vessels have not been described. In this manuscript, we evaluate the oxygenation changes induced by MRT in an intracerebral 9L gliosarcoma model., Methods: Tissue responses to MRT (two orthogonal arrays (2 × 400Gy)) were studied using magnetic resonance-based measurements of local blood oxygen saturation (MR&#95;SO2) and quantitative immunohistology of RECA-1, Type-IV collagen and GLUT-1, marker of hypoxia., Results: In tumors, MR&#95;SO2 decreased by a factor of 2 in tumor between day 8 and day 45 after MRT. This correlated with tumor vascular remodeling, i.e. decrease in vessel density, increases in half-vessel distances (×5) and GLUT-1 immunoreactivity. Conversely, MRT did not change normal brain MR&#95;SO2, although vessel inter-distances increased slightly., Conclusion: We provide new evidence for the differential effect of MRT on tumor vasculature, an effect that leads to tumor hypoxia. As hypothesized formerly, the vasculature of the normal brain exposed to MRT remains sufficiently perfused to prevent any hypoxia., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

This feasibility work assesses the therapeutic effectiveness of minibeam radiation therapy, a new synchrotron radiotherapy technique. In this new approach the irradiation is performed on 9L gliosarcoma-bearing rats with arrays of parallel beams of width 500-700 µm. Two irradiation configurations were compared: a lateral unidirectional irradiation and two orthogonal arrays interlacing at the target. A dose escalation study was performed. A factor of three gain in the mean survival time obtained for some animals paves the way for further exploration of the different possibilities of this technique and its further optimization.

To determine whether temozolomide is an active agent in the treatment of children with high-grade astrocytomas and whether survival is influenced by the expression of the O6-methylguanine-methyltransferase gene (MGMT) in these patients. In the Children's Oncology Group study ACNS0126, 107 patients with a diagnosis of anaplastic astrocytoma (AA), glioblastoma multiforme (GBM), or gliosarcoma were enrolled. All patients underwent concomitant chemoradiotherapy with temozolomide, followed by adjuvant chemotherapy with temozolomide. The outcomes were compared with those of children treated in Children's Cancer Group (CCG) study CCG-945. Formalin-fixed, paraffin-embedded tumor tissue was available in 71 cases for immunohistochemical analysis of MGMT expression. Ninety patients were deemed eligible, 31 with AA, 55 with GBM, and 4 with other eligible diagnoses. The 3-year event-free survival (EFS) and overall survival (OS) rates were 11 ± 3% and 22 ± 5%, respectively. There was no evidence that temozolomide given during radiation therapy and as adjuvant therapy resulted in improved EFS compared with that found in CCG-945 (p = 0.98). The 3-year EFS rate for AA was 13 ± 6% in ACNS0126 compared with 22 ± 5.5% in CCG-945 (p = 0.95). The 3-year EFS rate for GBM was 7 ± 4% in ACNS0126 compared with 15 ± 5% in CCG-945 (p = 0.77). The 2-year EFS rate was 17 ± 5% among patients without MGMT overexpression and 5 ± 4% among those with MGMT overexpression (p = 0.045). Temozolomide failed to improve outcome in children with high-grade astrocytomas. MGMT overexpression was adversely associated with survival.

Gliosarcoma is a rare variant of Glioblastoma Multiforme (GBM). It is a very aggressive tumour and usually managed like GBM. Treatment of choice is surgery with good surgical margins followed by radiotherapy (60 Gy). Median survival is seven months. Here we present a case report of 55 years old male who was diagnosed as brain tumour in left temporoparietal region. It turned out to be gliosarcoma after surgical resection and histopathological evaluation.

Objective: Buthus martensi Karsch (BmK) CT, a kind of scorpion toxin peptide, was found to inhibit glioma cell proliferation in previous researches. (131)I-BmK CT may have more inhibition effect and could be used as a glioma cell-targeted therapy and imaging agent. The purpose of this study was to investigate whether (131)I-BmK CT could specifically conjugate with C6 glioma cell and induce glioma cell inhibition in vitro., Methods: After cloning, expression, and purification, BmK CT was labeled with (131)I by indirect labeling (Bolton-Hunter method). The cell conjugation experiment was performed to investigate the connection between the reciprocal of cell conjugation rate and the reciprocal of cell count. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) method and flow cytometry were used to detect the inhibition effect of BmK CT and (131)I-BmK CT on glioma cell proliferation., Results: (131)I-BmK CT was successfully prepared with the overall yield of 34.5%. The cell conjugation experiment indicated that (131)I-BmK CT could specifically conjugate with C6 cells. MTT tests indicated that both BmK CT and (131)I-BmK CT could inhibit C6 growth. The ability of (131)I-BmK CT to inhibit cell growth is superior to that of BmK CT. The inhibitory rate (IR) of glioma cells was 60.5% (p < 0.01) at the concentration of 2 microg/mL with BmK CT. And the IR was 71.2% (p < 0.01) at the radioactivity concentration of 50 microCi/mL (concentration was much lower than 2 microg/mL) with (131)I-BmK CT. BmK CT could block the C6 glioma cell cycle in the G0/G1 stage. (131)I-BmK CT blocked the cell cycle in the S stage (the proportions of C6 in the S, G0/G1, and G2/M phases were 24.5% +/- 0.4% vs. 44.0% +/- 2.3%, 63.9% +/- 0.6% vs. 51.8% +/- 1.6%, and 11.6% +/- 1.0% vs. 4.3 +/- 0.7% [p < 0.05], respectively, at an initial radioactivity concentration of 50 microCi/mL)., Conclusions: On the basis of cytology experiments, it was found that (131)I-BmK CT could specifically conjugate with C6 glioma cell and inhibit cell growth. Hence, it may be used as a glioma-targeted agent.

Purpose: Tumour hypoxia affects cancer biology and therapy-resistance in both animals and humans. The purpose of this study was to determine whether EF5 ([2-(2-nitro-1-H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)-acetamide]) binding and/or radioactive drug uptake correlated with single-dose radiation response in 9L gliosarcoma tumours., Materials and Methods: Twenty-two 9L tumours were grown in male Fischer rats. Rats were administered low specific activity (18)F-EF5 and their tumours irradiated and assessed for cell survival and hypoxia. Hypoxia assays included EF5 binding measured by antibodies against bound-drug adducts and gamma counts of (18)F-EF5 tumour uptake compared with uptake by normal muscle and blood. These assays were compared with cellular radiation response (in vivo to in vitro assay). In six cases, uptake of tumour versus muscle was also assayed using images from a PET (positron emission tomography) camera (PENN G-PET)., Results: The intertumoural variation in radiation response of 9L tumour-cells was significantly correlated with uptake of (18)F-labelled EF5 (i.e., including both bound and non-bound drug) using either tumour to muscle or tumour to blood gamma count ratios. In the tumours where imaging was performed, there was a significant correlation between the image analysis and gamma count analysis. Intertumoural variation in cellular radiation response of the same 22 tumours was also correlated with mean flow cytometry signal due to EF5 binding., Conclusion: To our knowledge, this is the first animal model/drug combination demonstrating a correlation of radioresponse for tumour-cells from individual tumours with drug metabolism using either immunohistochemical or non-invasive techniques.

To analyze the effects of the microbeam width (25, 50 and 75 microm) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 microm wide microbeams, all spaced 211 microm on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 microm wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of approximately 50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 microm width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 microm or 25 microm widths when used with a 211 microm on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are kept constant in all groups. The use of 50 microm wide microbeams combined with moderate peak doses resulted in a higher therapeutic ratio.

The technical feasibility of temporal and spatial fractionations of the radiation dose has been evaluated using synchrotron microbeam radiation therapy for brain tumors in rats. A significant increase in lifespan (216%, p < 0.0001) resulted when three fractions of microbeam irradiation were applied to the tumor through three different ports, orthogonal to each other, at 24 h intervals. However, there were no long-term survivors, and immunohistological studies revealed that 9 L tumors were not entirely ablated.

The epidemiology and natural history of adult gliosarcomas (GSMs), as well as patient and treatment factors associated with outcome, are ill defined. Patients over 20 years of age with GSM diagnosed from 1988 to 2004 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. Kaplan-Meier survival analysis and Cox models were used to examine outcomes. Similar analyses were conducted for patients diagnosed with glioblastoma (GBM) over the same time period. GSM represented 2.2% of the 16,388 patients identified with either GSM or GBM. No significant differences between GSM and GBM were identified with respect to age, gender, race, tumor size, or use of adjuvant radiation therapy (RT). Patients with GSM were more likely to have temporal lobe involvement and undergo some form of tumor resection. The most important analyzed factors influencing GSM overall survival were age, extent of resection, and use of adjuvant RT. After adjusting for factors impacting overall survival, the prognosis for GSM appears slightly worse than for GBM (HR = 1.17, 95% CI, 1.05-1.31). GSM is a rare malignancy that presents very similarly to GBM with a slightly greater propensity for temporal lobe involvement. Optimal treatment remains to be defined. However, these retrospective findings suggest tumor excision, as opposed to biopsy only, and adjuvant RT may improve outcome. Despite therapy, prognosis remains dismal and outcomes may be inferior to those seen in GBM patients.

Purpose: This open-label, prospective, single-arm, phase II study combined erlotinib with radiation therapy (XRT) and temozolomide to treat glioblastoma multiforme (GBM) and gliosarcoma. The objectives were to determine efficacy of this treatment as measured by survival and to explore the relationship between molecular markers and treatment response., Patients and Methods: Sixty-five eligible adults with newly diagnosed GBM or gliosarcoma were enrolled. We intended to treat patients not currently treated with enzyme-inducing antiepileptic drugs (EIAEDs) with 100 mg/d of erlotinib during XRT and 150 mg/d after XRT. Patients receiving EIAEDs were to receive 200 mg/d of erlotinib during XRT and 300 mg/d after XRT. After XRT, the erlotinib dose was escalated until patients developed tolerable grade 2 rash or until the maximum allowed dose was reached. All patients received temozolomide during and after XRT. Molecular markers of epidermal growth factor receptor (EGFR), EGFRvIII, phosphatase and tensin homolog (PTEN), and methylation status of the promotor region of the MGMT gene were analyzed from tumor tissue. Survival was compared with outcomes from two historical phase II trials., Results: Median survival was 19.3 months in the current study and 14.1 months in the combined historical control studies, with a hazard ratio for survival (treated/control) of 0.64 (95% CI, 0.45 to 0.91). Treatment was well tolerated. There was a strong positive correlation between MGMT promotor methylation and survival, as well as an association between MGMT promotor-methylated tumors and PTEN positivity shown by immunohistochemistry with improved survival., Conclusion: Patients treated with the combination of erlotinib and temozolomide during and following radiotherapy had better survival than historical controls. Additional studies are warranted.

Purpose: Despite beneficial effects of irradiation/chemotherapy on survival of glioblastoma (GBM) patients, collateral damage to intact neural tissue leads to "radiochemobrain" and reduced quality of life in survivors. For prophylactic neuroprotection, erythropoietin (EPO) is a promising candidate, provided that concerns regarding potential tumor promoting effects are alleviated., Methods and Materials: Human GBM-derived cell lines U87, G44, G112, and the gliosarcoma-derived line G28 were treated with EPO, with and without combinations of irradiation or temozolomide (TMZ). Responsiveness of glioma cells to EPO was measured by cell migration from spheroids, cell proliferation, and clonogenic survival. Implantation of U87 cells into brains of nude mice, followed 5 days later by EPO treatment (5,000 U/kg intraperitoneal every other day for 2 weeks) should reveal effects of EPO on tumor growth in vivo. Reverse transcriptase-polymerase chain reaction was performed for EPOR, HIF-1alpha, and epidermal growth factor receptor (EGFR)vIII in cell lines and 22 human GBM specimens., Results: EPO did not modulate basal glioma cell migration and stimulated proliferation in only one of four cell lines. Importantly, EPO did not enhance tumor growth in mouse brains. Preincubation of glioma cells with EPO for 3 h, followed by irradiation and TMZ for another 24 h, resulted in protection against chemoradiation-induced cytotoxicity in three cell lines. Conversely, EPO induced a dose-dependent decrease in survival of G28 gliosarcoma cells. In GBM specimens, expression of HIF-1alpha correlated positively with expression of EPOR and EGFRvIII. EPOR and EGFRvIII expression did not correlate., Conclusions: EPO is unlikely to appreciably influence basal glioma growth. However, concomitant use of EPO with irradiation/chemotherapy in GBM patients is not advisable.

Background: Gliosarcomas (GS) are biphasic brain tumors composed of glioblastoma multiforme (GBM) and sarcomatous component. Therapeutic approaches include maximum surgical decompression with postoperative radiotherapy. Outcomes in gliosarcoma are poor despite multimodality management., Aims: To analyze the outcome in patients of GS treated in our institute over a period of 15 years and compare it with GBM treated during the same period., Settings and Design: Clinical records of the post-irradiated GS patients and GBM patients seen between 1990 and 2004 were retrieved., Materials and Methods: Demographic and treatment variables were evaluated for their influence on overall survival (OS). The survival outcomes of GBM and GS treated during the same period were also compared., Statistical Analysis: Univariate analysis was carried out using the Kaplan-Meier method and tested using log-rank test for significance., Results: During these 15 years, 24 evaluable GS patients were treated as compared to 251 evaluable patients of GBM. There was a slight male preponderance in GS (14 males vs.10 females) with a median age of 50 years. All patients underwent surgery followed by post-operative radiotherapy (median dose of 60 Gy). None of the patient or treatment related factors were found to be significantly influencing their OS. Median OS in GS was 7.3 months compared to 7.5 months in GBM patients (P = 0.790)., Conclusions: The OS appears to be similar for GS and GBM. None of the demographic variables appeared to prognosticate the survivals of GS.

Purpose: Lipid nanocapsules (LNC) entrapping lipophilic complexes of (188)Re ((188)Re(S(3)CPh)(2)(S(2)CPh) [(188)Re-SSS]) were investigated as a novel radiopharmaceutical carrier for internal radiation therapy of malignant gliomas. The present study was designed to evaluate the efficacy of intra-cerebral administration of (188)Re-SSS LNC by means of convection-enhanced delivery (CED) on a 9L rat brain tumour model., Methods: Female Fischer rats with 9L glioma were treated with a single injection of (188)Re-SSS LNC by CED 6 days after cell implantation. Rats were put into random groups according to the dose infused: 12, 10, 8 and 3 Gy in comparison with blank LNC, perrhenate solution (4 Gy) and non-treated animals. The radionuclide brain retention level was evaluated by measuring (188)Re elimination in faeces and urine over 72 h after the CED injection. The therapeutic effect of (188)Re-SSS LNC was assessed based on animal survival., Results: CED of (188)Re perrhenate solution resulted in rapid drug clearance with a brain T (1/2) of 7h. In contrast, when administered in LNC, (188)Re tissue retention was greatly prolonged, with only 10% of the injected dose being eliminated at 72 h. Rat median survival was significantly improved for the group treated with 8 Gy (188)Re-SSS LNC compared to the control group and blank LNC-treated animals. The increase in the median survival time was about 80% compared to the control group; 33% of the animals were long-term survivors. The dose of 8 Gy proved to be a very effective dose, between toxic (10-12 Gy) and ineffective (3-4 Gy) doses., Conclusions: These findings show that CED of (188)Re-loaded LNC is a safe and potent anti-tumour system for treating malignant gliomas. Our data are the first to show the in vivo efficacy of (188)Re internal radiotherapy for the treatment of brain malignancy.

The aim of this work focuses on the description of the short-term response of a 9L brain tumor model and its vasculature to microbeam radiation therapy (MRT) using magnetic resonance imaging (MRI). Rat 9L gliosarcomas implanted in nude mice brains were irradiated by MRT 13 days after tumor inoculation using two orthogonal arrays of equally spaced 28 planar microbeams (25 microm width, 211 microm spacing and dose 500 Gy). At 1, 7 and 14 days after MRT, apparent diffusion coefficient, blood volume and vessel size index were mapped by MRI. Mean survival time after tumor inoculation increased significantly between MRT-treated and untreated groups (23 and 28 days respectively, log-rank test, p < 0.0001). A significant increase of apparent diffusion coefficient was observed 24 h after MRT in irradiated tumors versus non-irradiated ones. In the untreated group, both tumor size and vessel size index increased significantly (from 7.6 +/- 2.2 to 19.2 +/- 4.0 mm(2) and +23%, respectively) between the 14th and the 21st day after tumor cell inoculation. During the same period, in the MRT-treated group, no difference in tumor size was observed. The vessel size index measured in the MRT-treated group increased significantly (+26%) between 14 and 28 days of tumor growth. We did not observe the significant difference in blood volume between the MRT-treated and untreated groups. MRT slows 9L tumor growth in a mouse brain but MRI results suggest that the increase in survival time after our MRT approach may be rather due to a cytoreduction than to early direct effects of ionizing radiation on tumor vessels. These results suggest that MRT parameters need to be optimized to further damage tumor vessels.

Aims and Background: Gliosarcomas are rare malignant primary brain tumors that usually affect the fifth or sixth decades of life. The purpose of this study was to describe our experience with such lesions in elderly patients and to establish their prognosis factors., Methods: Between 1993 and 2001, 7 patients over 60 years of age were treated at our institute for cerebral gliosarcomas. All patients underwent surgery for total or at least sub-total removal of a neoplastic mass., Results: Owing to poor clinical conditions (Karnofsky performance score = 40), one patient was not treated postoperatively. Remaining patients were treated with whole-brain radiotherapy, whereas concomitant chemotherapy (temozolomide) was administrated only to 4 patients. Histological examination showed the prevalence of sarcomatous aspects in 3 patients; the gliomatous aspect prevailed in 4 patients., Conclusions: Sarcomatous aspects and multimodality treatment (surgery, radiotherapy and chemotherapy) were associated with a better prognosis and showed in these elderly patients a trend similar to that of young people.

The purpose of this work was the understanding of microbeam radiation therapy at the ESRF in order to find the best compromise between curing of tumors and sparing of normal tissues, to obtain a better understanding of survival curves and to report its efficiency. This method uses synchrotron-generated x-ray microbeams. Rats were implanted with 9L gliosarcomas and the tumors were diagnosed by MRI. They were irradiated 14 days after implantation by arrays of 25 microm wide microbeams in unidirectional mode, with a skin entrance dose of 625 Gy. The effect of using 200 or 100 microm center-to-center spacing between the microbeams was compared. The median survival time (post-implantation) was 40 and 67 days at 200 and 100 microm spacing, respectively. However, 72% of rats irradiated at 100 microm spacing showed abnormal clinical signs and weight patterns, whereas only 12% of rats were affected at 200 microm spacing. In parallel, histological lesions of the normal brain were found in the 100 microm series only. Although the increase in lifespan was equal to 273% and 102% for the 100 and 200 microm series, respectively, the 200 microm spacing protocol provides a better sparing of healthy tissue and may prove useful in combination with other radiation modalities or additional drugs.

We report a 48-year-old woman with primary diffuse leptomeningeal gliomatosis (PDLG) histologically diagnosed as gliosarcoma. She was admitted complaining of headache, numbness of the right arm, double vision, and visual field defects. Computerized tomography (CT) scans showed ventricular dilatation consistent with communicating hydrocephalus. Magnetic resonance imaging (MRI) revealed diffuse meningeal thickening and gadolinium enhancement without a definite intraparenchymal lesion. Whole-spine MRI demonstrated across-the-board dural thickening and gadolinium enhancement. Cytological examination showed atypical anaplastic cells. As no diagnosis could be made she underwent biopsy of the leptomeninges. Histological examination of the specimen returned a diagnosis of gliosarcoma. Despite chemotherapy and radiotherapy she died 11 months after admission. Autopsy findings included gliosarcoma in the leptomeninges and spinal cord without an underlying parenchymal tumor. To our knowledge, this is the first report of primary diffuse leptomeningeal gliosarcomatosis.

Gliosarcoma is a highly malignant brain tumor consisting of both a glioblastoma and a mesenchymal component. The latter typically resembles fibrosarcoma, but differentiation patterns resembling osteosarcoma, chondrosarcoma, angiosarcoma and rhabdomyosarcoma have also been described. Molecular-genetic studies have shown that both glioblastoma and the mesenchymal component share identical cytogenetic abnormalities or mutations, suggesting a monoclonal origin from glial cells. We report an unusual case of gliosarcoma that presented as a large intracerebral tumor with infiltration of the temporal bone and the soft tissues in the infratemporal fossa. Microscopically, the tumor consisted of alternating areas of glioblastoma and fibrosarcoma. Focally, areas ofosteosarcomatous and liposarcomatous differentiation were found. Although gliosarcoma with transcranial penetration is very rare, it should be suspected in case of intracranial tumor with glioblastoma-imaging features, infiltration of bone and extracranial growth. Our case of liposarcomatous differentiation in gliosarcoma--together with another very recently reported similar case--expands the morphologic heterogeneity of this peculiar brain tumor.

Object: To improve the effectiveness of boron neutron capture therapy (BNCT) for malignant gliomas, the authors used epithermal rather than thermal neutrons for deep penetration and two boron compounds-sodium borocaptate (BSH) and boronophenylalanine (BPA)-with different accumulation mechanisms to increase the boron level in tumors while compensating for each other's faults., Methods: Thirteen patients, 10 of whom harbored a glioblastoma multiforme (GBM), one a gliosarcoma, one an anaplastic astrocytoma, and one an anaplastic oligoastrocytoma, were treated using this modified BNCT between January 2002 and December 2003. Postoperatively, neuroimaging revealed that only one patient with a GBM had no lesion enhancement postoperatively. The patients underwent 18F-BPA positron emission tomography, if available, to assess the accumulation and distribution of BPA before neutron radiotherapy. The neutron fluence rate was estimated using the Simulation Environments for Radiotherapy Applications dose-planning system before irradiation. The patients' volume assessments were performed using magnetic resonance (MR) imaging or computerized tomography (CT) scanning. Improvements in the disease as seen on neuroimages were assessed between 2 and 7 days after irradiation to determine the initial effects of BNCT; its maximal effects were also analyzed on serial neuroimages. The mean tumor volume before BNCT was 42.3 cm3. Regardless of the pre-BNCT tumor volume, in every patient harboring an assessable lesion, improvements on MR or CT images were recognized both at the initial assessment (range of volume reduction rate 17.4-71%, mean rate 46.4%) and at follow-up assessments (range of volume reduction rates 30.3-87.6%, mean rate 58.5%). More than 50% of the contrast-enhanced lesions disappeared in eight of the 12 patients during the follow-up period., Conclusions: This modified BNCT produced a good improvement in malignant gliomas, as seen on neuroimages.

Purpose: To develop a valid treatment strategy for recurrent high-grade gliomas using stereotactic hypofractionated reirradiation based on biologic imaging and temozolomide., Patients and Methods: The trial included a total of 44 patients with recurrent high-grade gliomas (1 patient with anaplastic oligodendroglioma, 8 with anaplastic astrocytoma, 33 with glioblastoma multiforme, and 2 with gliosarcoma) after previous surgery and postoperative conventional radiotherapy +/- chemotherapy. For fractionated stereotactic radiotherapy (SFRT) treatment planning, the gross tumor volume was defined by (11)C-methionine positron emission tomography (MET-PET) or (123)I-alpha-methyl-tyrosine (IMT) single-photon computed emission tomography (SPECT)/computed tomography (CT)/magnetic resonance imaging (MRI) fusion in 82% of the patients and by CT/T1+gadolinium-MRI image fusion in 18% of the patients. Six fractions of 5 Gy were administered in 6 days. In 29 of 44 patients (66%), chemotherapy with temozolomide (200 mg/m(2) body surface/day) was given in one to two cycles before and four to five cycles after SFRT. The patients were evaluated in follow-up by clinical investigators and MRI or CT every 3 months after SFRT until death. In cases suspicious for radiation necrosis, a MET-PET or IMT-SPECT investigation was performed., Results: The median survival time in the whole group was 8 months. Treatment planning based on PET(SPECT)/CT/MRI imaging was associated with improved survival in comparison to treatment planning using CT/MRI alone: median survival time 9 months vs. 5 months (p = 0.03, log-rank). Median survival time were 11 months for patients who received SFRT based on biologic imaging plus temozolomide and significantly lower, 6 months for patients treated with SFRT without biologic imaging, without temozolomide or without both (p = 0.008, log rank). The most important prognostic factor in univariate analysis was a long interval between initial diagnosis and recurrence (p = 0.0002, log-rank). In the multivariate model, time interval to retreatment (p = 0.006) and temozolomide (p = 0.04) remained statistically significant. No acute neurologic toxicity Grade 3 or higher and no Grade 4 hematologic toxicity was observed., Conclusion: This is the first study of biologic imaging optimized SFRT plus temozolomide in recurrent high-grade gliomas. It demonstrates the feasibility and safety of this approach. The most striking result of the trial is the statistically significant longer survival time in the univariate analysis for patients reirradiated using MET-PET or IMT-SPECT/CT/MRI image fusion in the treatment planning, in comparison to patients treated based on MRI/CT alone. Multivariate analysis confirmed a significant survival benefit from multimodal treatment (i.e., addition of temozolomide), despite the limited number of patients. Whether treatment planning with SPECT/PET independently influences survival has to be studied in a larger series of patients.

The steroid dexamethasone sodium phosphate (DEX) is routinely used to treat edema in brain tumor patients. The objective of the present study was to evaluate the effects of DEX on the uptake of boronophenylalanine (BPA) using the rat 9L gliosarcoma tumor model and surrounding brain tissue. Two steroid dosage protocols were used. The high-dose DEX protocol involved five 3mg/kg intraperitoneal injections at 47, 35, 23, 11 and 1 h prior to the administration of the BPA for a total dose of 15 mg DEX/kg rat. The low-dose DEX administration protocol involved two doses of 1.5mg/kg at 17 h and 1h prior to BPA injection for a total dose of 3mg DEX/kg rat. The control animals received no pretreatment, prior to the administration of BPA. Seventeen days after tumor implantation, rats were injected i.p. with 0.014 ml/g body weight BPA solution (1200 mg BPA/kg; approximately 59 mg (10)B/kg). In all groups, rats were euthanized at 3h after BPA injection. Administration of the steroid had an effect on tumor weight, which decreased to approximately 78% (p > 0.05) of the control weight in the low-dose DEX group, and approximately 48% (p < 0.001) of the control weight in the high-dose DEX group. At 3 h after the administration of BPA, the concentration of boron in tumor was comparable (p > 0.1) in the control and high-dose DEX groups. The lowest mean value (73.8+/-1.6 microg/g) was obtained in the low-dose DEX group. This was significantly lower (p > 0.02) than the tumor boron contents in the high-dose DEX and control groups, which were 81.1+/-1.9 and 79.9+/-1.7 microg/g, respectively. Tumor:blood boron partition ratios for the control, low- and high-dose DEX groups were 2.3, 2.3 and 2.5, respectively. Boron concentrations were also measured in the normal brain and in the zone of brain adjacent to the tumor exhibiting edema. Although treatment with DEX had no appreciable effect on boron uptake in the normal brain of the rat, after the administration of BPA, it did impact on the boron levels in the zone of peritumoral edema. After the high-dose DEX administration protocol, boron levels in the zone of edema were reduced by approximately 14% (p < 0.02). This finding suggests that BPA targeting of tumor cells in the peritumoral zone could be compromised by DEX. These cells appear to play a critical role in tumor recurrence after BNCT or conventional radiotherapy.

The (11)B(p,alpha)(8)Be* nuclear reaction was assessed for its ability to quantitatively map the in vivo subcellular distribution of boron within gliosarcomas treated with a boronated neutron capture therapy agent. Intracranial 9L gliosarcomas were produced in Fischer 344 rats. Fourteen days later, the majority of the rats were treated with f-boronophenylalanine and killed humanely 30 or 180 min after intravenous injection. Freeze-dried tumor cryosections were imaged using the (11)B(p,alpha)(8)Be* nuclear reaction and proton microbeams obtained from the nuclear microprobe at Lawrence Livermore National Laboratory. The (11)B distributions within cells could be imaged quantitatively with spatial resolutions down to 1.5 microm, minimum detection limits of 0.8 mg/kg, and acquisition times of several hours. These capabilities offer advantages over alpha-particle track autoradiography, electron energy loss spectroscopy, and secondary ion mass spectrometry (SIMS) for quantification of (11)B in tissues. However, the spatial resolution, multi-isotope capability, and analysis times achieved with SIMS are superior to those achieved with (11)B(p,alpha)(8)Be* analysis. When accuracy in quantification is crucial, the (11)B(p,alpha)(8)Be* reaction is well suited for assessing the microdistribution of (11)B. Otherwise, SIMS may well be better suited to image the microdistribution of boron associated with neutron capture therapy agents in biological tissues.

Production of DNA damage is the basis of cancer treatments such as chemo- and radiotherapy. Such treatments induce mitotic catastrophe, a form of cell death resulting from abnormal mitosis and leading to the formation of interphase cells with multiple micronuclei. In this study, we compared apoptosis induction and micronuclei formation to assess the DNA damage provoked in vivo by cytotoxic agents in established 9L rat gliosarcoma tumors expressing a mutated p53 gene. Results from TUNEL assays revealed the efficiency of local gamma-irradiation at the tumor site to induce apoptosis within 9L tumor mass. However, little or no apoptosis was detected after systemic (ip) injection of cisplatin (1 mg/kg). Interestingly, the micronuclei assays showed that not only gamma-irradiation but also cisplatin treatment led to an increase in the emergence of binucleated cells with micronuclei. Apoptosis induction and micronuclei emergence are thus not absolutely correlated. However, micronuclei assays, rarely performed on solid tumors, appear more sensitive than apoptosis assays in evaluating DNA damage linked to chemotherapy.

Our laboratory has employed replication-defective herpes simplex virus type 1 gene transfer vectors for treatment of animal models of human malignant glioblastoma. The base vectors were defective for the immediate early (IE) genes ICP4, ICP27, and ICP22 but expressed the IE gene ICP0, which can arrest tumor cell division, and an IE thymidine kinase (alpha-tk) gene construct that mediates suicide gene therapy (SGT) in the presence of ganciclovir (GCV). Previously, we reported that SGT using ICP0/alpha-tk vectors in nude mouse models of glioblastoma was improved by coexpression of the gap-junction-forming protein connexin43 (Cx43) or human tumor necrosis factor alpha (TNF alpha). We also showed that further gains in therapeutic outcome could be achieved by combining TNF alpha-enhanced SGT with gamma-knife radiosurgery (GKR). To expand these observations, we have first repeated these studies in immunocompetent rats with brain tumors derived from implanted 9L gliosarcoma cells and second compared the most efficient vector from this study with a new recombinant vector, NUREL-C2, which expressed both TNF alpha and Cx43 along with ICP0 and alpha-tk. Results from the first part indicated that our ICP0/alpha-tk/TNF alpha vector in combination with GKR provides an effective therapy although this treatment was not statistically better than GKR combined with the ICP0/alpha-tk/Cx43 vector. Our observations in the second part suggested that NUREL-C2 may be more effective than the ICP0/alpha-tk/TNF alpha vector in combination treatments with GCV (P = 0.08) or GCV plus GKR (P = 0.10). GKR significantly enhanced the efficacy of NUREL-C2/GCV treatment (P = 0.02) as well as other virus/GCV treatments (P < or = 0.05). Conversely, the efficacy of GKR was significantly improved by both the ICP0/alpha-tk/TNF alpha vector and NUREL-C2 in combination with GCV (P = 0.02 and P < 0.01, respectively). Together these results indicate that NUREL-C2 may be an attractive candidate for Phase I gene-therapy safety studies in patients with recurrent malignant glioblastoma.

Purpose: Analysis of the results of radiotherapy in a large group of cerebral gliomas with identification of prognostic factors and the outcome with respect to different decades of treatment., Patients and Methods: Two decades (1979-1999) of radiotherapy in supratentorial astrocytic and oligodendroglial tumors (n = 821) at the University Hospital Groningen were retrospectively evaluated. Prognostic factors for survival were analyzed. Two decades of radiotherapy treatment were compared with respect to radiotherapy dose and treatment-field design., Results: Glioblastoma multiforme, including gliosarcoma, was the most frequent supratentorial glioma (n = 442) with a poor survival, i.e., median survival time (MST) 7 months, especially in patients > 50 years of age and with poor performance. Patients with good performance were selected for radiotherapy with an optimum dose of 60 Gy local-field irradiation. However, in patients with poor prognosis, no radiotherapy was applied or a shorter treatment scheme was given. Anaplastic astrocytomas (n = 131) were treated in the same way as glioblastoma multiforme. Over time, a decrease in radiation dose (from 60 to 45 Gy) and from whole brain irradiation to local-field treatment was observed, following the literature. In low-grade gliomas, prognostic factors for survival were age, performance, and extent of resection. Gemistocytic astrocytoma (n = 15) had an inferior survival compared to astrocytoma (MST 46 vs. 54 months), but a superior survival compared to anaplastic astrocytoma (MST 10 months). The presence of an oligodendroglial component in a glioma implied a superior survival compared to the astrocytic gliomas. The inherent biology of the glioma is reflected by the study of recurrent tumors with progression to higher grades of malignancy in 32-40% and by the histology of recurrent oligodendroglial tumors. In comparing two decades of radiotherapy in gliomas, no differences in survival were observed despite the technological improvements. However, reduction in long-term side effects was not evaluated, especially in low-grade gliomas which were treated in the second decade of the study with local fields only and a reduced radiotherapy dose using computerized three-dimensional (3-D) planning., Conclusion: Radiotherapy does not cure cerebral glioma. Prognostic factors for survival are histopathologic classification and grading, age, and patient performance. Technological improvements do not improve survival, but possibly reduce late effects.

Background: In a previous study, we found that Gadobenate dimeglumine (Gd-BOPTA) resulted in a significantly greater Gd uptake by brain tumor tissue than Gadopentate dimeglumine (Gd-DTPA). Therefore, we investigated whether Gd-BOPTA is an efficient agent for neutron capture therapy (NCT)., Materials and Methods: Four groups of Fisher344 rats (control, neutron (n), n+ Gd-DTPA, n+ Gd-BOPTA) were subcutaneously injected 9L gliosarcoma cells in both hind legs. Gd-BOPTA and Gd-DTPA (0.05 mmol/g tumor weight) were injected directly into the tumor. At the peak of Gd uptake, thermal neutron irradiation was applied., Results: Two Gd+ groups showed pronounced tumor growth delay as compared with the control and neutron groups (p = 0.0053, 0.0064, respectively). Furthermore, the BOPTA group showed significantly prolonged delay of tumor growth as compared to the DTPA group (p = 0.033)., Conclusion: This is the first report of Gd-NCT to demonstrate that Gd-BOPTA serve as an effective compound for NCT. Better cytocidal effects of Gd-BOPTA warrant further investigation of subcellular Gd distribution.

Objectives: Ischaemic stroke attributable to malignant brain tumour is a rarely reported phenomenon and even various imaging techniques including angiography do not necessarily lead to an accurate diagnosis., Case Description: A 46-year-old, previously healthy man developed apoplectic symptoms with slight right sided hemiparesis and global aphasia. The computed tomography (CT) scan showed lesions of the left temporal lobe and the paraventricular white matter suggestive of left middle cerebral artery (MCA) infarction. Carotid angiography demonstrated compression of the M1 segment of the MCA and occlusion of temporal MCA. The patient initially refused magnetic resonance imaging (MRI) because of claustrophobia. Because of fluctuating symptoms and successive worsening of the condition over weeks an MRI scan was conducted under general anaesthesia. Beneath temporal, opercular, and subcortical infarctions it revealed a left temporal tumour. A tumour biopsy disclosed a gliosarcoma (WHO grade IV). Microscopical examination of the surgical specimen demonstrated invasion of tumour cells into the wall of a greater pre-existing blood vessel., Conclusions: Malignant brain tumours may cause ischaemic infarction. This is a rare but important differential diagnosis for the origin of strokes. The authors describe the first case with infiltration of intracranial blood vessels by tumour cells of a gliosarcoma.

Purpose: A Phase II trial was conducted by the Radiation Therapy Oncology Group (RTOG) to compare the survival of patients with glioblastoma multiforme treated with topotecan combined with standard cranial radiotherapy (RT) for matched patients treated in prior RTOG studies. A secondary objective was to document the acute and late toxicities of this combination of chemotherapy and RT., Methods and Materials: Eighty-seven patients with histologically confirmed glioblastoma multiforme received standard cranial RT (60 Gy/30 fractions in 6 weeks) plus topotecan 1.5 mg/m2 per day i.v. for 5 d/wk every 3 weeks for 3 cycles. Eighty-four patients were evaluated, of whom 60 (71%) were > or =50 years, 44 (52%) were men, and 61 (73%) had a Karnofsky performance status of > or =80. Twenty-nine percent of patients had undergone biopsies, 48% partial resections, and 21% gross total resections. Two resections were unspecified as to the extent of tumor removal. Fourteen percent of patients were recursive partitioning analysis Class III, 46% were Class IV, 35% were Class V, and 5% were Class VI., Results: The median survival was 9.3 months. Sixty-seven patients (80%) had progression. The 1-year survival rate was 32%. One patient remained alive without recurrence. RTOG 9513 patients were matched with patients in an RTOG clinical trial database from previous clinical trials. The matching variables were age, Karnofsky performance status, mental status, and prior surgery. No statistically significant difference was found between the survival of the study patients and that of the matched patients from the RTOG database. Fifty-four percent of patients had Grade IV acute toxicity. The toxicity was primarily hematologic. Four patients had Grade III late central nervous system toxicities., Conclusion: Topotecan administered at a dose of 1.5 mg/m2 per day i.v. for 5 d/wk every 3 weeks for 3 cycles given concurrently with standard cranial RT for glioblastoma does not produce a statistically significant survival advantage over previously tested therapies. Other methods of administration of topotecan or other camptothecins may provide more effective radiosensitization.

Purpose: To investigate the safety of thrice-daily hyperfractionated radiotherapy (RT) given in conjunction with BCNU (carmustine) in high-grade gliomas., Methods and Materials: Patients >18 years old with newly diagnosed high-grade gliomas were eligible. The dose of radiation was 5040 cGy, with a 1440-cGy boost in 180 cGy fractions delivered thrice daily in two 6-day periods with a 2-week interval. BCNU (200 mg/m(2)) was administered on the first day of radiation, then every 7 weeks for 1 year and every 10 weeks for another year., Results: Eighteen patients were enrolled. The mean age was 49.6 years. Sixteen patients had astrocytomas (Grade 3 or 4 in 5 and 11 patients, respectively) and 2 had oligoastrocytomas (Grade 3 and 4 in 1 patient each). One underwent total resection, 9 subtotal resection, and 8 biopsy only. Thirteen patients had stable disease, 4 regression, and 1 progression. The median time to progression was 37.8 weeks. The median overall survival was 44.4 weeks. Nine patients had neurologic toxicities, including 2 deaths at 69 and 139 weeks., Conclusion: This regimen is unacceptably toxic. Factors that could have contributed to the toxicity may include the total radiation dose, thrice-daily hyperfractionation, and the concurrent use of i.v. BCNU.

Radiotherapeutic doses for malignant gliomas are generally palliative because greater, supposedly curative doses would impart clinically unacceptable damage to nearby vital CNS tissues. To improve radiation treatment for human gliomas, we evaluated microbeam radiation therapy, which utilizes an array of parallel, microscopically thin (<100 microm) planar beams (microbeams) of synchrotron-generated X rays. Rats with i.c. 9L gliosarcoma tumors were exposed laterally to a single microbeam, 27 pm wide and 3.8 mm high, stepwise, to produce irradiation arrays with 50, 75, or 100 microm of on-center beam spacings and 150, 250, 300, or 500 Gy of in-slice, skin-entrance, single-exposure doses. The resulting array size was 9 mm wide and 10.4 mm high (using three 3.8-mm vertical tiers); the beam's median energy was -70 keV. When all data were collated, the median survival was 70 days; no depletion of nerve cells was observed. However, when data from the highest skin-entrance dose and/or the smallest microbeam spacings were excluded, the median survival time of the subset of rats was 170 days, and no white matter necrosis was observed. Others have reported unilateral single-exposure broad-beam irradiation of i.c. 9L gliosarcomas at 22.5 Gy with a median survival of only -34 days and with severe depletion of neurons. These results suggest that the therapeutic index of unidirectional microbeams is larger than that of the broad beams and that an application for microbeam radiation therapy in treating certain malignant brain tumors may be found in the future.

Boron neutron capture therapy (BNCT) is dependent on the selective accumulation of boron-10 in tumor cells relative to the contiguous normal cells. Ion microscopy was used to evaluate the microdistribution of boron-10 from p-boronophenylalanine (BPA) in the 9L rat gliosarcoma and the F98 rat glioma brain tumor models. Four routes of BPA administration were used: i.p. injection, intracarotid (i.c.) injection [with and without blood-brain barrier disruption (BBB-D)], and continuous timed i.v. infusions. i.p. injection of BPA in the 9L gliosarcoma resulted in a tumor-to-brain (T:Br) boron-10 concentration ratio of 3.7:1 when measured at the tumor-normal brain interface. In the F98 glioma, i.c injection of BPA resulted in a T:Br ratio of 2.9:1, and this increased to 5.4:1 when BBB-D was performed. The increased tumor boron uptake would potentially enhance the therapeutic ratio of BNCT by >25%. At present, ion microscopy is the only technique to provide a direct measurement of the T:Br boron-10 concentration ratio for tumor cells infiltrating normal brain. In the 9L gliosarcoma, this ratio was 2.9:1 after i.p. administration. In the F98 glioma, i.c injection resulted in a ratio of 2.2:1, and this increased to 3.0:1 after BBB-D. Ion microscopy revealed a consistent pattern of boron-10 microdistribution for both rat brain tumor models. The boron-10 concentration in the main tumor mass (MTM) was approximately twice that of the infiltrating tumor cells. One hour after a 2-h i.v. infusion of BPA in rats with the 9L gliosarcoma, tumor boron-10 concentrations were 2.7 times higher than that of infiltrating tumor cells [83 +/- 23 microg/g tissue versus 31 +/- 12 microg/g tissue (mean +/- SD)]. Continuous 3- and 6-h i.v. infusions of BPA in the 9L gliosarcoma resulted in similar high boron-10 concentrations in the MTM. The boron-10 concentration in infiltrating tumor cells was two times lower than the MTM after a 3-h infusion. After 6 h, the boron-10 concentration in infiltrating tumor cells had increased nearly 90% relative to the 2- and 3-h infusions. A 24-h i.v. infusion resulted in similar boron-10 levels between the MTM and the infiltrating tumor cells. Boron concentrations in the normal brain were similar for all four infusion times (approximately 20 microg/g tissue). These results are important for BNCT, because clinical protocols using a 2-h infusion have been performed with the assumption that infiltrating tumor cells contain equivalent amounts of boron-10 as the MTM. The results reported here suggest that this is not the case and that a 6-h or longer infusion of BPA may be necessary to raise boron-10 levels in infiltrating tumor cells to that in the MTM.

Background and Purpose: Gliosarcomas are rare biphasic neoplasms of the central nervous system composed of a glioblastoma multiforme (GBM) admixed with a sarcomatous component. There are conflicting reports regarding their clinical aggressiveness. Four hundred and twenty-two consecutive patients with GBM were treated at our hospital between 1980 and 1999, among them 12 gliosarcomas. The goal of this study was to examine clinical features, treatment, survival and patterns of failure of gliosarcoma patients and to compare them with the entire group of GBM patients. This comparison was refined by a matched pair analysis with a group of 12 GBM patients selected for age, Karnofsky performance status, resection status, fractionation scheme and total dose (control GBM group)., Materials and Methods: Seven gliosarcoma patients were male, five female, with a median age of 56 years (range 37-76 years). The median tumor size was 4.5 cm (range 3-8 cm). The locations, all supratentorial, included temporal in six, parietal in five, frontal in four and occipital in one patient. All patients underwent tumor resection followed by postoperative radiation therapy., Results: Median survival was 11.5 months for the gliosarcoma group, 8.1 months for the entire GBM group (log rank test, P=0.16) and 11.0 months for the control GBM group (log rank test, P=0.36). All gliosarcoma patients had local tumor recurrences and died due to neurologic causes within 19.3 months after radiation therapy., Conclusions: With regard to clinical features, survival and patterns of failure, gliosarcomas and GBM cannot be distinguished clinically. Therefore, the same principles should be applied for the treatment of these tumors.

Takagaki, M., Ono, K., Masunaga, S-I., Kinashi, Y., Oda, Y., Miyatake, S-I., Hashimoto, N., Powell, W., Sood, A. and Spielvogel, B. F. Boronated Dipeptide Borotrimethylglycylphenylalanine as a Potential Boron Carrier in Boron Neutron Capture Therapy for Malignant Brain Tumors. Radiat. Res. 156, 118-122 (2001).A boronated dipeptide, borotrimethylglycylphenylalanine (BGPA), was synthesized as a possible boron carrier for boron neutron capture therapy (BNCT) for malignant brain tumors. In vitro, at equal concentrations of (10)B in the extracellular medium, BGPA had the same effect in BNCT as p-boronophenylalanine (BPA). Boron analysis was carried out using prompt gamma-ray spectrometry and track-etch autoradiography. The tumor:blood and tumor:normal brain (10)B concentration ratios were 8.9 +/- 2.1 and 3.0 +/- 1.2, respectively, in rats bearing intracranial C6 gliosarcomas using alpha-particle track autoradiography. The IC(50), i.e. the dose capable of inhibiting the growth of C6 gliosarcoma cells by 50% after 3 days of incubation, was 5.9 x 10(-3) M BGPA, which is similar to that of 6.4 x 10(-3) M for BPA. The amide bond of BGPA is free from enzymatic attack, since it is protected from hydrolysis by the presence of a boron atom at the alpha-carbon position of glycine. These results suggest promise for the use of this agent for BNCT of malignant brain tumors. Further preclinical studies of BGPA are warranted, since BGPA has advantages over both BPA and BSH.

The biodistributions of carborane-containing copper porphyrins, CuTCP and CuTCPH, have been studied previously in mice bearing subcutaneously implanted mammary carcinomas. We now report biodistributions of those porphyrins in Fischer 344 rats bearing intracranial and/or multiple subcutaneous isogeneic 9L gliosarcomas (9LGS). The porphyrin was given either by i.v. infusion or by multiple i.p. injections. When 190 mg CuTCPH/kg body weight was given to the rats by i.v. infusion, median tissue boron concentrations (microg/g) 3 days after the end of infusion were: 64 in subcutaneous tumor, 13 in intracranial tumor, 1 in blood and 3 in brain. When 450 mg CuTCPH/kg body weight was given to the rats by serial i.p. injections, the median concentrations (microg B/g) 4 days after the last injection were: 117 in subcutaneous tumor, 50 in intracranial tumor, 4 in blood, and 4 in brain. CuTCPH biodistribution was also studied in xenografts of the human malignant gliomas U87 and U373, and of the murine EMT-6 mammary carcinoma and the rat 9LGS, each grown subcutaneously in mice with severe combined immunodeficiency (SCIDs). In SCIDs, median boron concentrations (microg/g) 2 days after the last s.c. injection of a total of 190 mg CuTCPH/kg body weight were: 251 in U373, 33 in U87, <0.6 in blood and <0.5 in brain. Because there were such high boron levels in the U373, and because xenografted U373 is similar to spontaneous intracerebral human glioblastoma multiforme (GBM) microscopically, CuTCPH could prove useful as a boron carrier for boron neutron-capture therapy (BNCT) of GBM and of other human malignant gliomas.

New clinical protocols are being developed that will entail the administration of considerably higher doses of the boron delivery agent boronophenylalanine (BPA) than those in current clinical use. Fractionation (2 or 4 fractions) of BPA mediated boron neutron capture therapy (BNCT) is also under consideration at some clinical centres. Given the considerably higher infusion volumes that will be entailed in the delivery of BPA in the new high dosage protocols, there will be a requirement to extend the gap between fractions to 2 or more days. In order to assess the effects of a 2 fraction protocol on the therapeutic efficacy of BPA mediated BNCT, a series of split dose irradiations (two equal fractions) were undertaken using the rat intracranially implanted 9L gliosarcoma model. A single dose exposure to BPA mediated BNCT of 3.0 Gy resulted in long term survival levels of 50%. Survival levels increased to 71% and 77% with a 3 and 5 day gap between dose fractions (two equal fractions), respectively, using the same total dose. A further increase in the time interval between dose fractions to 7 days resulted in a reduction in survival to 36%. However, there was no significant difference between the single dose and the 3, 5 and 7 day survival data (P > 0.1) The difference between the 5 and 7 day split dose survival data was of border-line significance (P = 0.05). It is anticipated that mucositis, could become a potential problem in future BNCT clinical protocols involving higher doses, larger field sizes or multiple fields. The potential sparing of the oral mucosa, due to repopulation during the interval between the two fractions, was investigated using a series of split dose BPA mediated BNC irradiations. The ventral surface of the rat tongue was utilised as a model for oral mucosa. The ED50 (50% incidence) values for the ulceration end point were 3.0+/-0.1, 3.2+/-0.1, 3.0+/-0.1 and 3.6+/-0.1 Gy, for 3, 5, 7 and 9 day splits between doses, respectively. It is evident from this data that there were no significant changes in the ED50 (p < 0.001) until the 9 day dose split, when the ED50 value was 20% higher than the ED50 value after a 7 day split. It was concluded that the two fraction BNCT protocol, with dose splits of up to 5 days, did not diminish the therapeutic response of the rat 9L gliosarcoma, when compared with a single dose BNCT protocol. Tolerance of the oral mucosa to BNC irradiation was not increased until there was a 9 day gap between fractions. However, the beneficial effects of dose sparing at this time interval between doses, would probably be counteracted by a reduction in the therapeutic effectiveness of the BNCT modality, due to repopulation of tumour clonogens between doses.

We characterized the interphase cell death of 9L gliosarcoma after high-dose-rate, low-energy photon irradiation using the Photon Radiosurgery System (PRS), a novel device for interstitial radiotherapy. Within 24 hours after irradiation with a dose of 18 Gray, 22.0% of cells underwent metabolic cell death, whereas dead cells in controls stayed less than 5.0% (p<0.005). In the majority of sensitive cells, loss of membrane integrity preceded the lethal morphological changes. The response was dose-dependent over the range of 9-18 Gray, but saturation was obtained over 18 Gray. On the other hand, a significant (p < 0.01) increase in the number of TUNEL-positive cells with apoptotic morphology was detected 6-24 hours after irradiation, but the fraction remained 1.9-2.1% of the population and was independent of the doses between 9 and 25 Gray. Apoptotic cells were rarely observed in the control cells (0.3-0.6%). Our data indicate that single high-dose irradiation induces both necrotic and apoptotic interphase cell death in 9L gliosarcoma, but rapid cell death mostly occurs through the non-apoptotic pathway.

A number of anti-angiogenic substances are now under evaluation, both experimentally and clinically, as potential agents for the treatment of cancer. It has recently been demonstrated that anti-angiogenic agents can increase the therapeutic potential of photon irradiation in a range of tumour models. In the present communication a preliminary assessment is made of the effects of shark cartilage on the response of the rat 9L gliosarcoma to boron neutron capture therapy (BNCT). Shark cartilage was administered orally as an aqueous suspension at a daily dose of approximately 2000 mg kg-1 body weight. The mean survival time of rats receiving no treatment was 20.7 +/- 0.5 days post intracranial tumour implantation. Administration of shark cartilage alone extended the survival time. Two of the rats treated with shark cartilage were healthy and fully active at the end of the evaluation period (43 days post implantation). At autopsy the brain tumours of these animals were a factor of approximately 4 smaller than controls. In a repeat study with shark cartilage alone the survival time was extended by approximately 30%. After boronophenylalanine-mediated BNCT, with or without shark cartilage, the survival time of rats that eventually became moribund was increased by a factor of approximately 2 relative to controls. In both treatment groups approximately 20% of rats were healthy at 1 year after BNCT. There was no evidence of residual tumour at post-mortem. It was concluded that shark cartilage, when given alone, significantly increased the survival time of tumour-bearing rats, presumably owing to an anti-angiogenic effect. However, the survival data suggested that boronophenylalanine-mediated BNCT did not appear to be enhanced by the administration of shark cartilage.

Glioblastoma multiforme (GBM) is the most common primary human brain tumor. About 7000 new cases are diagnosed yearly in the USA and GBM is almost invariably fatal within a few years after it is diagnosed. Despite current neurosurgical and radiotherapeutic tumor cytoreduction methods, in most cases occult foci of tumor cells infiltrate surrounding brain tissues and cause recurrent disease. Therefore the combination of neurosurgical and radiotherapeutic debulking methods with therapies to inhibit occult GBM cells should improve prognosis. In this study we have combined boron neutron-capture therapy (BNCT), a novel binary radiotherapeutic treatment modality that selectively irradiates tumor tissue and largely spares normal brain tissue, with immunoprophylaxis, a form of active immunization initiated soon after BNCT treatment, to treat advanced, clinically relevantly-sized brain tumors in rats. Using a malignant rat glioma model of high immunogenicity, the 9L gliosarcoma, we have shown that about half of the rats that would have died after receiving BNCT debulking alone, survived after receiving BNCT plus immunoprophylaxis. Further, most of the surviving rats display immunological-based resistance to recurrent 9LGS growth six months or more after treatment. To our knowledge this study represents the first time BNCT and immunoprophylaxis have been combined to treat advanced brain tumors in rats.

Glioblastoma multiforme (GBM) is the most common primary human brain tumor. About 7000 new cases are diagnosed yearly in the USA. Despite current neurosurgical and postoperative radiotherapeutic tumor cytoreduction methods, in most cases occult foci of tumor cells infiltrate surrounding edematous brain tissues and cause recurrent disease within one year. GBM is almost invariably fatal within a few years after it is diagnosed. Our goal is to achieve long-term control of GBM by combining immunoprophylaxis with a radiation-based technique, such as boron neutron-capture therapy (BNCT), potentially capable of specifically targeting the infiltrating tumor cells while sparing the surrounding normal brain tissue. It has long been known that the subcutaneous (sc) injection of irradiated cells or untreated cultured cells (and the removal of the resulting tumors) derived from the well characterized, highly immunogenic 9L gliosarcoma (9LGS) rat model into young isogenic rats can prevent tumor growth after subsequent sc or intracranial (ic) injection of untreated, otherwise lethal 9LGS cells. In this study we have confirmed, quantified and extended those findings to study the efficacy of such immunological memory in normal aging rats and in aging rats previously treated for ic 9LGS tumors by BNCT. (1) The sc injection of 5,000,000 untreated 9LGS cells and the surgical removal of the resulting tumors (method A) protected 80% of normal young rats from an ic challenge with 10,000 untreated 9LGS cells, and a single sc injection of 5,000,000 lethally X-irradiated 9LGS cells (method B) protected 66% of them, but multiple sc injections with a crude particulate fraction prepared from 9LGS cells were not protective. Protection is long-lasting since contralateral ic rechallenge of six-month survivors with an injection of 10,000 viable 9LGS cells resulted in 100% survival. (2) Normal one-year-old rats were only slightly less protected than were normal young rats, approximately 70% rather than approximately 80% (method A) and approximately 60% rather than approximately 66% (method B). (3) BNCT treatment alone resulted in partial immunological protection, as 30% of one-year post-BNCT survivors of ic 9LGS tumors prevailed after contralateral ic rechallenge with 10,000 viable 9LGS cells. Moreover a single sc immunization with 5,000,000 untreated 9LGS cells prior to ic rechallenge boosted survival from 30% to 100%. The relevance of these observations to strategies of preclinical experimentation for immunoprophylaxis of malignant gliomas is discussed.

In Jan. 97 a gliosarcoma was diagnosed in a 61-year- old man after a 6-month history with neurological deficits. A total physical examination, laboratory tests, chest x-ray and abdominal ultrasound scanning revealed no gross abnormalities. Surgery was followed by brain radiation therapy and 6 months later there were metastases to the oral cavity, right palpebra and both lungs. The histological findings of the oral and palpebral metastases revealed only the sarcomatous component. We are aware of 15 cases of gliosarcoma with extraneural metastases, and in 4 of these, the metastases contained only the sarcomatous component. We believe that our case represents the fifth case of pure sarcomatous metastases.

Clinical trials of boron neutron capture therapy (BNCT) for glioblastoma multiforme are currently in progress using p-boronophenylalanine (BPA) as the 10B delivery agent. Enhancement of tumor boron uptake and/or the tumor-to-blood (T:B) boron concentration ratio would have the potential of significantly improving the therapeutic gain of BNCT. The effects of total dose, infusion time, and route of administration of BPA on tumor and blood boron concentrations were studied in rats bearing the 9L gliosarcoma. Increasing the total dose of BPA from 250 to 1000 mg/kg, administered intravenously over a 2-h infusion period, resulted in an increase in tumor boron concentration from approximately 30 to approximately 70 microg 10B/g, with a constant T:B boron concentration ratio of about 3.7:1. Similarly, extension of the infusion time from 2 to 6 h, at a constant dose-rate of 125 mg BPA/kg/h, resulted in an increase in tumor boron concentration from approximately 30 to approximately 80 microg 10B/g, while, again, maintaining a constant T:B ratio of about 3.7:1. In contrast, intracarotid infusion of BPA for 1 h at a dose rate of 125 mg BPA/kg resulted in an increase in the tumor boron concentration from approximately 26 to approximately 38 microg 10B/g with a corresponding increase in the T:B ratio from 3.5:1 to 5.0:1. The effects of these results on the therapeutic gain potentially achievable with BNCT are discussed.