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Barbara Fisher

Bio: Barbara Fisher is an academic researcher from University of Western Ontario. The author has contributed to research in topics: Radiation therapy & Temozolomide. The author has an hindex of 40, co-authored 116 publications receiving 26509 citations. Previous affiliations of Barbara Fisher include London Health Sciences Centre & Mayo Clinic.


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Journal ArticleDOI
TL;DR: Helical tomotherapy plans for craniospinal radiation were generated for the case of a 4-year-old boy with disseminated ependymoma and demonstrated excellent target coverage, homogeneity and organ sparing compared with a conventional linear accelerator based craniOSPinal radiation plan.
Abstract: Helical tomotherapy (HT) plans for craniospinal radiation were generated for the case of a 4-year-old boy with disseminated ependymoma The HT plans demonstrated excellent target coverage, homogeneity and organ sparing compared with a conventional linear accelerator based craniospinal radiation plan On the basis of this case study, further evaluation of HT for craniospinal radiotherapy seems justified

74 citations

Journal ArticleDOI
TL;DR: The results suggest concurrent and adjuvant TMZ does not confer a survival benefit in elderly GBM patients and a sequential approach may be a more effective and efficient strategy by selecting responding patients who may benefit most from subsequent salvage chemotherapy.
Abstract: The landmark Stupp study demonstrated a survival advantage with concomitant and adjuvant temozolomide (TMZ) with standard radiotherapy (RT) in glioblastoma multiforme (GBM) patients but excluded those older than 70 years. The prospective Roa study of older GBM patients treated with hypofractionated 3-week course RT demonstrated equivalence to standard 6-week course RT. Taken together, these trials suggest hypofractionated RT with TMZ may be a reasonable treatment option for elderly GBM patients. We conducted a retrospective review of GBM patients (age ≥60 years) treated with hypofractionated RT and temozolomide at our institution between 2000 and 2010. We identified 112 patients who received hypofractionated RT, with 57 receiving concurrent and adjuvant TMZ and 55 without concurrent chemotherapy. Of the 55 patients who received hypofractionated RT alone initially, 24 subsequently received TMZ as salvage treatment at time of progression. Among the concurrent RT + TMZ patients, mean age was 70 years (range 60–86), median KPS was 80 (range 30–100) and 24/57 (42%) received prior debulking surgery. Median overall survival (OS) among the RT + TMZ patients was 6.9 months (95% CI, 4.5–8.6). Patients without concurrent chemotherapy were similar in demographics (age, sex, corticosteroid use, KPS) except 34/55 (62%) were debulked (P-value 0.045.) Median OS was 9.3 months (95% CI, 5.9–11.8) (P-value 0.351). Sub-group analysis revealed patients treated with initial hypofractionated radiation with salvage TMZ had increased median OS of 13.3 months (95% CI, 9.9–19.3) (P-value 0.012). Our results suggest concurrent and adjuvant TMZ does not confer a survival benefit in elderly GBM patients. A sequential approach may be a more effective and efficient strategy by selecting responding patients who may benefit most from subsequent salvage chemotherapy.

67 citations

Journal ArticleDOI
TL;DR: Low-grade gliomas to radiotherapy are moderately radioresponsive and the best way to measure response remains uncertain because neither visual, area, nor volume changes confidently predicted clinical outcomes.
Abstract: Purpose: We set out to determine the rate of response of low-grade (WHO Grade II) gliomas to radiotherapy and analyze the relationship between radiographic response, symptom control and patient survival. Methods: Patients were eligible for this study if they had received radiotherapy for pathologically confirmed, residual, supratentorial low-grade astrocytoma, oligodendroglioma, or mixed glioma, and imaging studies (baseline and follow-up) were available for review . Percent change in tumor size and rate and timing of response were determined by maximum linear measurement, area measurement, volume measurement using an ellipsoid model, and vol- ume measurement by image segmentation. For each method, response to radiotherapy was defined firstly as a ‡ 50% decrease in tumor size (partial response), and secondly as a decrease equivalent to a 50% area decrease (normalized partial response). Relationships between radiographic response, clinical improvement and progression-free survival were analyzed using a Cox Proportional Hazard's model. Results: Twenty-one patients in a database (13 male, 8 female; ages 22-66 years) met the eligibility criteria. T wenty were imaged by com- puted tomography, 18 had an astrocytoma and 15 were irradiated soon after sur gery. Responses were common and not felt to be due to a steroid effect. Use of normalized response criteria improved agreement between assessment of response as determined by the 4 methods. Median time to maximum radiographic improvement was 2.8 months (range, 1.5-11). Sixteen patients (76%) were improved neurologi- cally, the median time to progression was 4.8 years and the 5-year progression-free survival rate was 43%. W e did not detect a statistically significant association between response (as measured by any method), symptomatology and progression-free survival. Conclusions: Low-grade gliomas are moderately radioresponsive. Use of volume measurement may over-estimate the number of partial responses unless a volume reduction equivalent to a 50% area decrease is used to define response. The best way to measure response remains uncer - tain because neither visual, area, nor volume changes confidently predicted clinical outcomes.

66 citations

Journal ArticleDOI
TL;DR: Long term follow up results for PCV given with RT at the time of initial diagnosis prolongs progression-free survival (PFS), but not overall survival (OS), compared with RT alone are reported.
Abstract: 2000 Background: Early results of R9802 (Shaw et al: J Clin Oncol. 2012; 30(25):3065-70) demonstrated that PCV given with RT at the time of initial diagnosis prolongs progression-free survival (PFS...

63 citations

Journal ArticleDOI
TL;DR: 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.
Abstract: 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/m 2 per day i.v. for 5 d/wk every 3 weeks for 3 cycles. Eighty-four patients were evaluated, of whom 60 (71%) were ≥50 years, 44 (52%) were men, and 61 (73%) had a Karnofsky performance status of ≥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/m 2 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.

61 citations


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Journal ArticleDOI
TL;DR: The addition of temozolomide to radiotherapy for newly diagnosed glioblastoma resulted in a clinically meaningful and statistically significant survival benefit with minimal additional toxicity.
Abstract: methods Patients with newly diagnosed, histologically confirmed glioblastoma were randomly assigned to receive radiotherapy alone (fractionated focal irradiation in daily fractions of 2 Gy given 5 days per week for 6 weeks, for a total of 60 Gy) or radiotherapy plus continuous daily temozolomide (75 mg per square meter of body-surface area per day, 7 days per week from the first to the last day of radiotherapy), followed by six cycles of adjuvant temozolomide (150 to 200 mg per square meter for 5 days during each 28-day cycle). The primary end point was overall survival. results A total of 573 patients from 85 centers underwent randomization. The median age was 56 years, and 84 percent of patients had undergone debulking surgery. At a median follow-up of 28 months, the median survival was 14.6 months with radiotherapy plus temozolomide and 12.1 months with radiotherapy alone. The unadjusted hazard ratio for death in the radiotherapy-plus-temozolomide group was 0.63 (95 percent confidence interval, 0.52 to 0.75; P<0.001 by the log-rank test). The two-year survival rate was 26.5 percent with radiotherapy plus temozolomide and 10.4 percent with radiotherapy alone. Concomitant treatment with radiotherapy plus temozolomide resulted in grade 3 or 4 hematologic toxic effects in 7 percent of patients.

16,653 citations

Journal ArticleDOI
TL;DR: Benefits of adjuvant temozolomide with radiotherapy lasted throughout 5 years of follow-up, and a benefit of combined therapy was recorded in all clinical prognostic subgroups, including patients aged 60-70 years.
Abstract: BACKGROUND: In 2004, a randomised phase III trial by the European Organisation for Research and Treatment of Cancer (EORTC) and National Cancer Institute of Canada Clinical Trials Group (NCIC) reported improved median and 2-year survival for patients with glioblastoma treated with concomitant and adjuvant temozolomide and radiotherapy. We report the final results with a median follow-up of more than 5 years. METHODS: Adult patients with newly diagnosed glioblastoma were randomly assigned to receive either standard radiotherapy or identical radiotherapy with concomitant temozolomide followed by up to six cycles of adjuvant temozolomide. The methylation status of the methyl-guanine methyl transferase gene, MGMT, was determined retrospectively from the tumour tissue of 206 patients. The primary endpoint was overall survival. Analyses were by intention to treat. This trial is registered with Clinicaltrials.gov, number NCT00006353. FINDINGS: Between Aug 17, 2000, and March 22, 2002, 573 patients were assigned to treatment. 278 (97%) of 286 patients in the radiotherapy alone group and 254 (89%) of 287 in the combined-treatment group died during 5 years of follow-up. Overall survival was 27.2% (95% CI 22.2-32.5) at 2 years, 16.0% (12.0-20.6) at 3 years, 12.1% (8.5-16.4) at 4 years, and 9.8% (6.4-14.0) at 5 years with temozolomide, versus 10.9% (7.6-14.8), 4.4% (2.4-7.2), 3.0% (1.4-5.7), and 1.9% (0.6-4.4) with radiotherapy alone (hazard ratio 0.6, 95% CI 0.5-0.7; p<0.0001). A benefit of combined therapy was recorded in all clinical prognostic subgroups, including patients aged 60-70 years. Methylation of the MGMT promoter was the strongest predictor for outcome and benefit from temozolomide chemotherapy. INTERPRETATION: Benefits of adjuvant temozolomide with radiotherapy lasted throughout 5 years of follow-up. A few patients in favourable prognostic categories survive longer than 5 years. MGMT methylation status identifies patients most likely to benefit from the addition of temozolomide. FUNDING: EORTC, NCIC, Nelia and Amadeo Barletta Foundation, Schering-Plough.

6,161 citations

Journal ArticleDOI
TL;DR: Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylation of theMGMT promoter did notHave such a benefit and were assigned to only radiotherapy.
Abstract: background Epigenetic silencing of the MGMT (O 6 -methylguanine–DNA methyltransferase) DNArepair gene by promoter methylation compromises DNA repair and has been associated with longer survival in patients with glioblastoma who receive alkylating agents. methods We tested the relationship between MGMT silencing in the tumor and the survival of patients who were enrolled in a randomized trial comparing radiotherapy alone with radiotherapy combined with concomitant and adjuvant treatment with temozolomide. The methylation status of the MGMT promoter was determined by methylation-specific polymerase-chain-reaction analysis. results The MGMT promoter was methylated in 45 percent of 206 assessable cases. Irrespective of treatment, MGMT promoter methylation was an independent favorable prognostic factor (P<0.001 by the log-rank test; hazard ratio, 0.45; 95 percent confidence interval, 0.32 to 0.61). Among patients whose tumor contained a methylated MGMT promoter, a survival benefit was observed in patients treated with temozolomide and radiotherapy; their median survival was 21.7 months (95 percent confidence interval, 17.4 to 30.4), as compared with 15.3 months (95 percent confidence interval, 13.0 to 20.9) among those who were assigned to only radiotherapy (P=0.007 by the log-rank test). In the absence of methylation of the MGMT promoter, there was a smaller and statistically insignificant difference in survival between the treatment groups. conclusions Patients with glioblastoma containing a methylated MGMT promoter benefited from temozolomide, whereas those who did not have a methylated MGMT promoter did not have such a benefit.

6,018 citations

Journal ArticleDOI
26 Sep 2008-Science
TL;DR: Recurrent mutations in the active site of isocitrate dehydrogenase 1 (IDH1) occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival.
Abstract: Glioblastoma multiforme (GBM) is the most common and lethal type of brain cancer. To identify the genetic alterations in GBMs, we sequenced 20,661 protein coding genes, determined the presence of amplifications and deletions using high-density oligonucleotide arrays, and performed gene expression analyses using next-generation sequencing technologies in 22 human tumor samples. This comprehensive analysis led to the discovery of a variety of genes that were not known to be altered in GBMs. Most notably, we found recurrent mutations in the active site of isocitrate dehydrogenase 1 (IDH1) in 12% of GBM patients. Mutations in IDH1 occurred in a large fraction of young patients and in most patients with secondary GBMs and were associated with an increase in overall survival. These studies demonstrate the value of unbiased genomic analyses in the characterization of human brain cancer and identify a potentially useful genetic alteration for the classification and targeted therapy of GBMs.

5,250 citations

Journal ArticleDOI
TL;DR: Mutations of NADP(+)-dependent isocitrate dehydrogenases encoded by IDH1 and IDH2 occur in a majority of several types of malignant gliomas.
Abstract: Background A recent genomewide mutational analysis of glioblastomas (World Health Organization [WHO] grade IV glioma) revealed somatic mutations of the isocitrate dehydrogenase 1 gene (IDH1) in a fraction of such tumors, most frequently in tumors that were known to have evolved from lower-grade gliomas (secondary glioblastomas). Methods We determined the sequence of the IDH1 gene and the related IDH2 gene in 445 central nervous system (CNS) tumors and 494 non-CNS tumors. The enzymatic activity of the proteins that were produced from normal and mutant IDH1 and IDH2 genes was determined in cultured glioma cells that were transfected with these genes. Results We identified mutations that affected amino acid 132 of IDH1 in more than 70% of WHO grade II and III astrocytomas and oligodendrogliomas and in glioblastomas that developed from these lower-grade lesions. Tumors without mutations in IDH1 often had mutations affecting the analogous amino acid (R172) of the IDH2 gene. Tumors with IDH1 or IDH2 mutations h...

4,853 citations