Canadian recommendations for the treatment of glioblastoma multiforme

Extended dosing (12 cycles) vs conventional dosing (6 cycles) of adjuvant temozolomide in adults with newly diagnosed high-grade gliomas: a randomized, single-blind, two-arm, parallel-group controlled trial

Purpose

Maximum safe surgical resection followed by adjuvant chemoradiation and temozolomide chemotherapy is the current standard of care in the management of newly diagnosed high grade glioma. However, there are controversies about the optimal number of adjuvant temozolomide cycles. This study aimed to compare the survival benefits of 12 cycles against 6 cycles of adjuvant temozolomide adults with newly diagnosed high grade gliomas.

Methods

Adult patients with newly diagnosed high grade gliomas, and a Karnofsky performance status>60%, were randomized to receive either 6 cycles or 12 cycles of adjuvant temozolomide. Patients were followed-up for assessment of overall survival (OS) and progression-free survival (PFS) by brain MRI every 3 months within the first year after treatment and then every six months.

Results

A total of 100 patients (6 cycles, 50; 12 cycles, 50) were entered. The rate of treatment completion in 6 cycles and 12 cycles groups were 91.3% and 55.1%, respectively. With a median follow-up of 26 months, the 12-, 24-, 36-, and 48-month OS rates in 6 cycles and 12 cycles groups were 81.3% vs 78.8%, 58.3% vs 49.8%, 47.6% vs 34.1%, and 47.6% vs 31.5%, respectively (p-value=.19). Median OS of 6 cycles and 12 cycles groups were 35 months (95% confidence interval (CI), 11.0 to 58.9) and 23 months (95%CI, 16.9 to 29.0). The 12-, 24-, 36-, and 48- month PFS rates in 6 cycles and 12 cycles groups were 70.8% vs 56.9%, 39.5% and 32.7%, 27.1% vs 28.8%, and 21.1% vs 28.8%, respectively (p=.88). The Median PFS of 6 cycles and 12 cycles groups was 18 months (95% CI, 14.8 to 21.1) and 16 (95% CI, 11.0 to 20.9) months.

Conclusion

Patients with newly diagnosed high grade gliomas treated with adjuvant temozolomide after maximum safe surgical resection and adjuvant chemoradiation do not benefit from extended adjuvant temozolomide beyond 6 cycles.

Trial registration

Prospectively registered with the Iranian Registry of Clinical Trials: IRCT20160706028815N3. Date registered: 18/03/14.

Impact of Extended Adjuvant Temozolamide Beyond 6 Months in the Management of Glioblastoma Patients

OBJECTIVES

Our study aimed to assess the benefit of prolonging adjuvant temozolomide (TMZ) therapy beyond 6 cycles in glioblastoma multiform patients.

MATERIALS AND METHODS

The medical records of 329 patients in 2 cancer centers in Egypt were reviewed from January 2008 to December 2018 who were diagnosed with diffuse gliomas. Data were collected on patient demographics, presenting complaints, tumor size, treatment modalities (extent of surgery, radiotherapy dose and technique, concomitant TMZ, and the number of adjuvant TMZ cycles), and reported adverse events.

RESULTS

In the studied cohort, 105 patients were treated with adjuvant TMZ, 33 patients received <6 cycles (TMZL), 41 patients received the standard 6 cycles (TMZS), and 31 patients received >6 cycles (TMZE). Our results showed the median overall survival in the TMZL arm was 8.47 months compared with 15.83 months in the TMZS arm and 27.33 months in the TMZE arm ( P < 0.001). Furthermore, a median progression-free survival of 6.35 months was reported in the TMZL group versus, 12.7 and 22.90 months in (TMZS) and (TMZE) groups, respectively( P < 0.001). In the multivariate analysis, the extended adjuvant TMZ with a hazard ratio of 3.106 (95% CI: 2.43-14.46; P < 0.001) was statistically significantly associated with a better outcome.

CONCLUSIONS

Extended adjuvant TMZ therapy beyond 6 cycles may significantly improve the progression-free survival and overall survival in patients with glioblastoma multiform.

Development and validation of an advanced ex vivo brain slice invasion assay to model glioblastoma cell invasion into the complex brain microenvironment

Organotypic cultures of murine brain slices are well-established tools in neuroscience research, including electrophysiology studies, modeling neurodegeneration, and cancer research. Here, we present an optimized ex vivo brain slice invasion assay that models glioblastoma multiforme (GBM) cell invasion into organotypic brain slices. Using this model, human GBM spheroids can be implanted with precision onto murine brain slices and cultured ex vivo to allow tumour cell invasion into the brain tissue. Traditional top-down confocal microscopy allows for imaging of GBM cell migration along the top of the brain slice, but there is limited resolution of tumour cell invasion into the slice. Our novel imaging and quantification technique involves embedding stained brain slices into an agar block, re-sectioning the slice in the Z-direction onto slides, and then using confocal microscopy to image cellular invasion into the brain tissue. This imaging technique allows for the visualization of invasive structures beneath the spheroid that would otherwise go undetected using traditional microscopy approaches. Our ImageJ macro (BraInZ) allows for the quantification of GBM brain slice invasion in the Z-direction. Importantly, we note striking differences in the modes of motility observed when GBM cells invade into Matrigel in vitro versus into brain tissue ex vivo highlighting the importance of incorporating the brain microenvironment when studying GBM invasion. In summary, our version of the ex vivo brain slice invasion assay improves upon previously published models by more clearly differentiating between migration along the top of the brain slice versus invasion into the slice.

Pattern of Recurrence of Glioblastoma Versus Grade 4 IDH-Mutant Astrocytoma Following Chemoradiation: A Retrospective Matched-Cohort Analysis

Background and Purpose: To quantitatively compare the recurrence patterns of glioblastoma (isocitrate dehydrogenase-wild type) versus grade 4 isocitrate dehydrogenase-mutant astrocytoma (wild type isocitrate dehydrogenase and mutant isocitrate dehydrogenase, respectively) following primary chemoradiation. Materials and Methods: A retrospective matched cohort of 22 wild type isocitrate dehydrogenase and 22 mutant isocitrate dehydrogenase patients were matched by sex, extent of resection, and corpus callosum involvement. The recurrent gross tumor volume was compared to the original gross tumor volume and clinical target volume contours from radiotherapy planning. Failure patterns were quantified by the incidence and volume of the recurrent gross tumor volume outside the gross tumor volume and clinical target volume, and positional differences of the recurrent gross tumor volume centroid from the gross tumor volume and clinical target volume. Results: The gross tumor volume was smaller for wild type isocitrate dehydrogenase patients compared to the mutant isocitrate dehydrogenase cohort (mean ± SD: 46.5 ± 26.0 cm³ vs 72.2 ± 45.4 cm³, P = .026). The recurrent gross tumor volume was 10.7 ± 26.9 cm³ and 46.9 ± 55.0 cm³ smaller than the gross tumor volume for the same groups (P = .018). The recurrent gross tumor volume extended outside the gross tumor volume in 22 (100%) and 15 (68%) (P= .009) of wild type isocitrate dehydrogenase and mutant isocitrate dehydrogenase patients, respectively; however, the volume of recurrent gross tumor volume outside the gross tumor volume was not significantly different (12.4 ± 16.1 cm³ vs 8.4 ± 14.2 cm³, P = .443). The recurrent gross tumor volume centroid was within 5.7 mm of the closest gross tumor volume edge for 21 (95%) and 22 (100%) of wild type isocitrate dehydrogenase and mutant isocitrate dehydrogenase patients, respectively. Conclusion: The recurrent gross tumor volume extended beyond the gross tumor volume less often in mutant isocitrate dehydrogenase patients possibly implying a differential response to chemoradiotherapy and suggesting isocitrate dehydrogenase status might be used to personalize radiotherapy. The results require validation in prospective randomized trials.

Evaluation of interim MRI changes during limited-field radiation therapy for glioblastoma and implications for treatment planning

BACKGROUND AND PURPOSE

Consensus for defining gross tumor volume (GTV) and clinical target volume (CTV) for limited-field radiation therapy (LFRT) of GBM are not well established. We leveraged a department MRI simulator to image patients before and during LFRT to address these questions.

MATERIALS AND METHODS

Supratentorial GBM patients receiving LFRT (46 Gy + boost to 60 Gy) underwent baseline MRI (MRI1) and interim MRI during RT (MRI2). GTV1 was defined as T1 enhancement + surgical cavity on MRI1 without routine inclusion of T2 abnormality (unless tumor did not enhance). The initial CTV margin was 15 mm from GTV1, and the boost CTV margin was 5-7 mm. The GTV1 characteristics were categorized into three groups: identical T1 and T2 abnormality (Group A), T1 only with larger T2 abnormality not included (Group B), and T2 abnormality when tumor lacked enhancement (Group C). GTV2 was contoured on MRI2 and compared with GTV1 plus 5-15 mm expansions.

RESULTS

Among 120 patients treated from 2014-2019, 29 patients (24%) underwent replanning based on MRI2. On MRI2, 84% of GTV2 were covered by GTV1 + 5 mm, 93% by GTV1 + 7 mm, and 98% by GTV1 + 15 mm. On MRI1, 43% of GTV1 could be categorized into Group A, 39% Group B, and 18% Group C. Group B's patterns of failure, local control, or progression-free survival were similar to Group A/C.

CONCLUSIONS

Initial CTV margin of 15 mm followed by a boost CTV margin of 7 mm is a reasonable approach for LFRT of GBM. Omitting routine inclusion of T2 abnormality from GTV delineation may not jeopardize disease control.

High-Grade Gliomas Located in the Right Hemisphere Are Associated With Worse Quality of Life

BACKGROUND

The impact of glioma location on quality of life (QOL) has not been conclusively studied, possibly due to the prohibitively high sample size that standard statistical analyses would require and the inherent heterogeneity of this disease. By using a novel algorithm, we investigated the impact of tumor location on QOL in a limited set of 53 consecutive patients.

METHODS

The glial tumors of 53 consecutive patients were segmented and registered to a standardized atlas. The Euclidian distance between 90 brain regions and each tumor's margin was calculated and correlated to the patient's self-reported QOL as measured by the Sherbrooke Neuro-Oncology Assessment Scale questionnaire.

RESULTS

QOL was not correlated to tumor volume, though a significant correlation was observed with its proximity to these areas: right supramarginal gyrus, right rolandic operculum, right superior temporal gyrus, right middle temporal gyrus, right angular gyrus, and right inferior parietal lobule. Interestingly, all identified areas are in the right hemisphere, and localized in the temporoparietal region. We postulate that the adverse relation between proximity to these areas and QOL results from disruption in visuospatial functioning.

CONCLUSIONS

Although the areas identified in this study are traditionally considered non-eloquent areas, tumor proximity to these regions showed more impact on QOL than any other brain regions. We postulate that this effect is mediated via an adverse impact on the visuospatial functioning.

Investigation of the potential anticancer effects of napelline and talatisamine dirterpenes on experimental brain tumor models

Brain cancers are one of the most aggressive tumours in humans. Especially, gliomas are among the deadliest of human cancers and show high resistance to chemotherapeutic agents. On the other hand, discovery of biologically effective non-synthetic biomaterials in treatments of different diseases, especially cancer, has continued to be one of the most popular research topics today. Therefore, we aimed to investigate biochemical, cytological and molecular genetic effects of napelline and talatisamine diterpenes in human U-87 MG glioma cells by using total antioxidant status and total oxidative status, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxphenyl)-2-(4-sulfophenyl)-2H-tetrozolium, inner salt and lactate dehydrogenase release assay and RT2 Prolifer PCR Arrays. Our results revealed that napelline and talatisamine exhibited cytotoxic effects at high doses. Napelline and talatisamine diterpenes increased apoptosis compared to control in U-87 MG cells. While napelline induced up-regulation of 50 and down-regulation of 13 genes, talatisamine induced up-regulation of 32 and down-regulation of 18 genes in U-87 MG cells. Napelline was shown to have a higher anticancer activity than talatisamine. We think that, napelline and talatisamine might be evaluated as potential chemotherapeutic agents for treatment of glioblastoma.

5-Aminolevulinic Acid Hydrochloride (5-ALA)-Guided Surgical Resection of High-Grade Gliomas: A Health Technology Assessment

BACKGROUND

High-grade gliomas are a type of malignant brain tumour. Optimal management often includes maximal surgical resection. 5-aminolevulinic acid hydrochloride (5-ALA) is an imaging agent that makes a high-grade glioma fluoresce under blue light, which can help guide the surgeon when removing the tumour. We conducted a health technology assessment of 5-ALA-guided surgical resection of high-grade gliomas, which included an evaluation of effectiveness, safety, the budget impact of publicly funding 5-ALA, and patient preferences and values.

METHODS

We performed a systematic literature search of the clinical evidence to retrieve systematic reviews, and selected and reported results from one review that was recent, of high quality, and relevant to our research question. We complemented the identified systematic review with a literature search to identify randomized controlled trials published after the review. We reported the risk of bias of each included study and the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We also performed a systematic economic literature search to identify economic studies that compared 5-ALA-guided surgical resection of high-grade gliomas with standard surgical care or other intraoperative imaging modalities. We did not conduct a primary economic evaluation due to lack of high-quality published clinical evidence evaluating 5-ALA-guided surgical resection. From the perspective of the Ontario Ministry of Health, we analyzed the 5-year budget impact of publicly funding 5-ALA-guided surgical resection for adults with newly diagnosed, primary, high-grade gliomas for which resection is considered feasible. To contextualize the potential value of 5-ALA, we spoke with someone who had experience with high-grade glioma, 5-ALA-guided resection, and standard surgical treatment.

RESULTS

We included one systematic review reporting on a single randomized controlled trial in the clinical evidence review. 5-ALA increased the proportion of patients achieving complete tumour resection compared with standard care (relative risk of incomplete resection 0.55, 95% confidence interval 0.42-0.71; GRADE: Low). Evidence was uncertain for an effect on overall survival with 5-ALA (hazard ratio for death 0.82, 95% confidence interval 0.62-1.07; GRADE: Low), but there may be an improvement in 6-month progression-free survival (GRADE: Very low). Adverse events between groups was insufficiently reported, but appeared similar between groups for overall and neurological adverse events, with an observed increase in neurological deficits 48 hours after surgery with 5-ALA (GRADE: Very low). The economic literature search identified five studies that met our inclusion criteria because they evaluated the cost-effectiveness of 5-ALA-guided surgical resection as compared with surgery with a standard operating microscope under white light ("white-light microscopy"). Most of these studies found 5-ALA-guided surgical resection was cost-effective compared to white-light microscopy for high-grade gliomas. However, all studies derived clinical model inputs of the comparative safety and effectiveness parameters of 5-ALA from limited and low-quality evidence. Public funding of 5-ALA-guided surgical resection in Ontario over the next 5 years would result in a budget impact of about $930,000 in year 1 to about $1,765,000 in year 5, yielding a total budget impact of about $7,500,000 over this period. The one participant we interviewed had experience with high-grade glioma, standard surgical treatment, and 5-ALA-guided resection. The participant felt that 5-ALA-guided resection resulted in accurate tumour removal and also found it reassuring that 5-ALA could help the surgeon better visualize the tumour.

CONCLUSIONS

5-ALA-guided surgical resection appears to improve the extent of resection of high-grade gliomas compared with surgery using standard white-light microscopy (GRADE: Low). The evidence suggests 5-ALA-guided resection may improve overall survival; however, we cannot exclude the possibility of no effect (Grade: Low). 5-ALA may improve 6-month progression-free survival, although the results are highly uncertain (GRADE: Very low). There is an uncertain impact on overall or neurological adverse events (GRADE: Very low). We did not identify any economic studies conducted from the perspective of the Ontario or Canadian public health care payer. Of the studies that met our inclusion criteria, most found 5-ALA-guided surgical resection was cost-effective compared to white-light microscopy for high-grade gliomas. However, clinical model inputs for the comparative effectiveness and safety of 5-ALA were based on limited and low-quality evidence. We estimate that publicly funding 5-ALA-guided surgical resection in Ontario over the next 5 years would result in a total 5-year budget impact of about $7,500,000. For people diagnosed with high-grade gliomas, 5-ALA is seen positively as a useful imaging tool for brain tumour resection.

Gliosarcomas: magnetic resonance imaging findings

BACKGROUND

Central nervous system (CNS) gliosarcoma (GSM) is a rare primary neoplasm characterized by the presence of glial and sarcomatous components.

OBJECTIVE

In this report, we describe the clinical and neuroimaging aspects of three cases of GSM and correlate these aspects with pathological findings. We also provide a brief review of relevant literature.

METHODS

Three patients were evaluated with magnetic resonance imaging (MRI), and biopsies confirmed the diagnosis of primary GSM, without previous radiotherapy.

RESULTS

The analysis of conventional sequences (T1, T1 after contrast injection, T2, Fluid attenuation inversion recovery, SWI and DWI/ADC map) and advanced (proton 1H MR spectroscopy and perfusion) revealed an irregular, necrotic aspect of the lesion, peritumoral edema/infiltration and isointensity of the solid component on a T2-weighted image. These features were associated with irregular and peripheral contrast enhancement, lipid and lactate peaks, increased choline and creatine levels in proton spectroscopy, increased relative cerebral blood volume (rCBV) in perfusion, multifocality and drop metastasis in one of the cases.

CONCLUSION

These findings are discussed in relation to the general characteristics of GSM reported in the literature.

A positive feedback loop involving nuclear factor IB and calpain 1 suppresses glioblastoma cell migration

Glioblastoma (GBM) is a brain tumor that remains largely incurable because of its highly-infiltrative properties. Nuclear factor I (NFI)-type transcription factors regulate genes associated with GBM cell migration and infiltration. We have previously shown that NFI activity depends on the NFI phosphorylation state and that calcineurin phosphatase dephosphorylates and activates NFI. Calcineurin is cleaved and activated by calpain proteases whose activity is, in turn, regulated by an endogenous inhibitor, calpastatin (CAST). The CAST gene is a target of NFI in GBM cells, with differentially phosphorylated NFIs regulating the levels of CAST transcript variants. Here, we uncovered an NFIB-calpain 1-positive feedback loop mediated through CAST and calcineurin. In NFI-hyperphosphorylated GBM cells, NFIB expression decreased the CAST-to-calpain 1 ratio in the cytoplasm. This reduced ratio increased autolysis and activity of cytoplasmic calpain 1. Conversely, in NFI-hypophosphorylated cells, NFIB expression induced differential subcellular compartmentalization of CAST and calpain 1, with CAST localizing primarily to the cytoplasm and calpain 1 to the nucleus. Overall, this altered compartmentalization increased nuclear calpain 1 activity. We also show that nuclear calpain 1, by cleaving and activating calcineurin, induces NFIB dephosphorylation. Of note, knockdown of calpain 1, NFIB, or both increased GBM cell migration and up-regulated the pro-migratory factors fatty acid-binding protein 7 (FABP7) and Ras homolog family member A (RHOA). In summary, our findings reveal bidirectional cross-talk between NFIB and calpain 1 in GBM cells. A physiological consequence of this positive feedback loop appears to be decreased GBM cell migration.

Effects of nuclear factor I phosphorylation on calpastatin (CAST) gene variant expression and subcellular distribution in malignant glioma cells

Malignant glioma (MG) is the most lethal primary brain tumor. In addition to having inherent resistance to radiation treatment and chemotherapy, MG cells are highly infiltrative, rendering focal therapies ineffective. Genes involved in MG cell migration and glial cell differentiation are up-regulated by hypophosphorylated nuclear factor I (NFI), which is dephosphorylated by the phosphatase calcineurin in MG cells. Calcineurin is cleaved and thereby activated by calpain proteases, which are, in turn, inhibited by calpastatin (CAST). Here, we show that the CAST gene is a target of NFI and has NFI-binding sites in its intron 3 region. We also found that NFI-mediated regulation of CAST depends on NFI's phosphorylation state. We noted that occupation of CAST intron 3 by hypophosphorylated NFI results in increased activation of an alternative promoter. This activation resulted in higher levels of CAST transcript variants, leading to increased levels of CAST protein that lacks the N-terminal XL domain. CAST was primarily present in the cytoplasm of NFI-hypophosphorylated MG cells, with a predominantly perinuclear immunostaining pattern. NFI knockdown in NFI-hypophosphorylated MG cells increased CAST levels at the plasma membrane. These results suggest that NFI plays an integral role in the regulation of CAST variants and CAST subcellular distribution. Along with the previous findings indicating that NFI activity is regulated by calcineurin, these results provide a foundation for further investigations into the possibility of regulatory cross-talk between NFI and the CAST/calpain/calcineurin signaling pathway in MG cells.

The relationship between repeat resection and overall survival in patients with glioblastoma: a time-dependent analysis

OBJECTIVEPrevious studies assessed the relationship between repeat resection and overall survival (OS) in patients with glioblastoma, but ignoring the timing of repeat resection may have led to biased conclusions. Statistical methods that take time into account are well established and applied consistently in other medical fields. The goal of this study was to illustrate the change in the effect of repeat resection on OS in patients with glioblastoma once timing of resection is incorporated.METHODSThe authors conducted a retrospective study of patients initially diagnosed with glioblastoma between January 2005 and December 2014 who were treated at Memorial Sloan Kettering Cancer Center. Patients underwent at least 1 craniotomy with both pre- and postoperative MRI data available. The effect of repeat resection on OS was assessed with time-dependent extended Cox regression controlling for extent of resection, initial Karnofsky Performance Scale score, sex, age, multifocal status, eloquent status, and postoperative treatment.RESULTSEighty-nine (55%) of 163 patients underwent repeat resection with a median time between resections of 7.7 months (range 0.5-50.8 months). Median OS was 18.8 months (95% confidence interval [CI] 16.3-20.5 months) from initial resection. When timing of repeat resection was ignored, repeat resection was associated with a lower risk of death (hazard ratio [HR] 0.62, 95% CI 0.43-0.90, p = 0.01); however, when timing was taken into account, repeat resection was associated with a higher risk of death (HR 2.19, 95% CI 1.47-3.28, p < 0.001).CONCLUSIONSIn this study, accounting for timing of repeat resection reversed its protective effect on OS, suggesting repeat resection may not benefit OS in all patients. These findings establish a foundation for future work by accounting for timing of repeat resection using time-dependent methods in the evaluation of repeat resection on OS. Additional recommendations include improved data capture that includes mutational data, development of algorithms for determining eligibility for repeat resection, more rigorous statistical analyses, and the assessment of additional benefits of repeat resection, such as reduction of symptom burden and enhanced quality of life.

Nuclear Factor I Represses the Notch Effector HEY1 in Glioblastoma

Glioblastomas (GBMs) are highly aggressive brain tumors with a dismal prognosis. Nuclear factor I (NFI) is a family of transcription factors that controls glial cell differentiation in the developing central nervous system. NFIs have previously been shown to regulate the expression of astrocyte markers such as glial fibrillary acidic protein (GFAP) in both normal brain and GBM cells. We used chromatin immunoprecipitation (ChIP)–on-chip to identify additional NFI targets in GBM cells. Analysis of our ChIP data revealed ~400 putative NFI target genes including an effector of the Notch signaling pathway, HEY1, implicated in the maintenance of neural stem cells. All four NFIs (NFIA, NFIB, NFIC, and NFIX) bind to NFI recognition sites located within 1 kb upstream of the HEY1 transcription site. We further showed that NFI negatively regulates HEY1 expression, with knockdown of all four NFIs in GBM cells resulting in increased HEY1 RNA levels. HEY1 knockdown in GBM cells decreased cell proliferation, increased cell migration, and decreased neurosphere formation. Finally, we found a general correlation between elevated levels of HEY1 and expression of the brain neural stem/progenitor cell marker B-FABP in GBM cell lines. Knockdown of HEY1 resulted in an increase in the RNA levels of the GFAP astrocyte differentiation marker. Overall, our data indicate that HEY1 is negatively regulated by NFI family members and is associated with increased proliferation, decreased migration, and increased stem cell properties in GBM cells.

Three-Dimensional Conformal Radiotherapy, Temozolomide Chemotherapy, and High-Dose Fractionated Stereotactic Boost in a Protocol-Driven, Postoperative Treatment Schedule for High-Grade Gliomas

Aims and background

No available scientific report deals with high-dose (≥70 Gy) radiotherapy plus temozolomide chemotherapy (TMZ CHT) in high-grade gliomas. The survival results of a protocol-driven, postoperative treatment schedule are reported here to contribute to the discussion on this issue.

Methods and study design

Uniform criteria were prospectively adopted for case selection during the period 1993–2006 in the management of 123 patients, and we progressively introduced three-dimensional conformal radiotherapy (3D-CRT, 60 Gy), TMZ CHT and a high-dose (70 Gy) stereotactic boost (HDSRT) in the treatment schedule. Palliative radiotherapy was delivered by whole brain irradiation (WBI, 50 Gy) for bulky tumors, whereas radical irradiation was performed with 3D-CRT throughout the study period. Two periods of accrual are considered: 36 patients were treated before 31 December 1999 (29.25%) and 87 (70.75%) after 1 January 2000. This subdivision was due to the implementation of HDSRT hardware and TMZ CHT from January 2000.

Results

The median overall survival was 13 months and the 1-, 2- and 3-year survival rates were 53%, 19.5% and 11.6%, respectively. The differences in survival related to the treatment variables were highly significant, both in univariate and multivariate analysis. The median survival and 1-, 2- and 3-year survival rates in the palliative WBI group were 9.75 months and 37%, 2%, and 0%, respectively; in the 3D-CRT group 17.25 months and 64%, 34%, and 15%, respectively; in the TMZ CHT concomitant with radiotherapy group 20 months and 61%, 39%, and 21%, respectively; in the TMZ CHT concomitant with and sequential to radiotherapy group 25.75 months and 84%, 54%, and 26%, respectively, and in the HDSRT group 22 months and 72%, 48%, and 37%, respectively. No symptomatic radiation necrosis occurred in any of the groups.

Conclusions

The results reported here are generally better than those reported in the literature. The selection of patients on the basis of favorable prognostic factors and suitability to the currently available, aggressive postoperative treatment resources can be the mainstay for improving therapeutic results. In particular, the new treatment option reported here (HDSRT in association with TMZ CHT) proved to be safe and effective in obtaining a relatively favorable outcome.

Adjuvant Radiation Therapy and Temozolomide in Gliosarcoma: Is It Enough? Case Series of Seven Patients

Objective:

We present our experience of gliosarcoma (GSM) in oncology tertiary care center over the last 5 years.

Materials and Methods:

We carried out a retrospective analysis of seven patients with GSM diagnosed between April 2008 and December 2012. Demographic data, clinicopathological data, treatment strategies employed, details of recurrence, and survival patterns were reviewed.

Results:

The median age at diagnosis was 54 years, ranging between 34 and 63 years with a female predominance (57.1% females). Headache and neurological deficit were the most common symptoms with parietal region being the most common site of lesion. Subtotal resection followed by concurrent chemoradiation therapy was delivered to six patients. The results following completion of planned schedule of concurrent chemoradiotherapy were quite disappointing with two patients having no evidence of disease, one patient was lost to follow-up, and other three had progressive disease. One patient with progressive disease subsequently received eight cycles of bevacizumab on a clinical trial protocol. Fifteen-month posttreatment, she had stable disease on follow-up.

Conclusions:

Our experience suggests that despite treatment, the diagnosis of GSM portends a poor prognosis and the use of bevacizumab could represent a treatment approach to improve outcome in these patients. Although the role of targeted therapy in GSM remains unclear because of paucity of experience, the treatment decision should be according to patient's performance status, ability, and willingness to receive additional treatment.

Impact on Radiation Dose and Volume V57 Gy of the Brain on Recurrence and Survival of Patients with Glioblastoma Multiformae

BACKGROUND

The aim of the study was to analyze impact of irradiated brain volume V57 Gy (volume receiving 57 Gy and more) on time to progression and survival of patients with glioblastoma.

PATIENTS AND METHODS

Dosimetric analysis of treatment plan data has been performed on 70 patients with glioblastoma, treated with postoperative radiochemotherapy with temozolomide, followed by adjuvant temozolomide. Patients were treated with 2 different methods of definition of treatment volumes and prescription of radiation dose. First group of patients has been treated with one treatment volume receiving 60 Gy in 2 Gy daily fraction (31 patients) and second group of the patients has been treated with "cone-down" technique, which consisted of two phases of treatment: the first phase of 46 Gy in 2 Gy fraction followed by "cone-down" boost of 14 Gy in 2 Gy fraction (39 patients). Quantification of V57 Gy and ratio brain volume/V57Gy has been done. Average values of both parameters have been taken as a threshold value and patients have been split into 2 groups for each parameter (values smaller/ lager than threshold value).

RESULTS

Mean value for V57 Gy was 593.39 cm3 (range 166.94 to 968.60 cm3), mean value of brain volume has was 1332.86 cm3 (range 1047.00 to 1671.90 cm3) and mean value of brain-to-V57Gy ratio was 2.46 (range 1.42 to 7.67). There was no significant difference between two groups for both V57 Gy and ratio between brain volume and V57 Gy.

CONCLUSIONS

Irradiated volume with dose 57 Gy or more (V57 Gy) and ration between whole brain volume and 57 Gy had no impact on time to progression and survival of patients with glioblastoma.

Recurrent glioblastomas in the elderly after maximal first-line treatment: does preserved overall condition warrant a maximal second-line treatment?

A growing literature supports maximal safe resection followed by standard combined chemoradiotherapy (i.e. maximal first-line therapy) for selected elderly glioblastoma patients. To assess the prognostic factors from recurrence in elderly glioblastoma patients treated by maximal safe resection followed by standard combined chemoradiotherapy as first-line therapy. Multicentric retrospective analysis comparing the prognosis and optimal oncological management of recurrent glioblastomas between 660 adult patients aged of < 70 years (standard group) and 117 patients aged of ≥70 years (elderly group) harboring a supratentorial glioblastoma treated by maximal first-line therapy. From recurrence, both groups did not significantly differ regarding Karnofsky performance status (KPS) (p = 0.482). Oncological treatments from recurrence significantly differed: patients of the elderly group received less frequently oncological treatment from recurrence (p < 0.001), including surgical resection (p < 0.001), Bevacizumab therapy (p < 0.001), and second line chemotherapy other than Temozolomide (p < 0.001). In multivariate analysis, Age ≥70 years was not an independent predictor of overall survival from recurrence (p = 0.602), RTOG-RPA classes 5-6 (p = 0.050) and KPS at recurrence <70 (p < 0.001), available in all cases, were independent significant predictors of shorter overall survival from recurrence. Initial removal of ≥ 90% of enhancing tumor (p = 0.004), initial completion of the standard combined chemoradiotherapy (p = 0.007), oncological treatment from recurrence (p < 0.001), and particularly surgical resection (p < 0.001), Temozolomide (p = 0.046), and Bevacizumab therapy (p = 0.041) were all significant independent predictors of longer overall survival from recurrence. Elderly patients had substandard care from recurrence whereas age did not impact overall survival from recurrence contrary to KPS at recurrence <70. Treatment options from recurrence should include repeat surgery, second line chemotherapy and anti-angiogenic agents.

Personalized Radiotherapy Planning Based on a Computational Tumor Growth Model

In this article, we propose a proof of concept for the automatic planning of personalized radiotherapy for brain tumors. A computational model of glioblastoma growth is combined with an exponential cell survival model to describe the effect of radiotherapy. The model is personalized to the magnetic resonance images (MRIs) of a given patient. It takes into account the uncertainty in the model parameters, together with the uncertainty in the MRI segmentations. The computed probability distribution over tumor cell densities, together with the cell survival model, is used to define the prescription dose distribution, which is the basis for subsequent Intensity Modulated Radiation Therapy (IMRT) planning. Depending on the clinical data available, we compare three different scenarios to personalize the model. First, we consider a single MRI acquisition before therapy, as it would usually be the case in clinical routine. Second, we use two MRI acquisitions at two distinct time points in order to personalize the model and plan radiotherapy. Third, we include the uncertainty in the segmentation process. We present the application of our approach on two patients diagnosed with high grade glioma. We introduce two methods to derive the radiotherapy prescription dose distribution, which are based on minimizing integral tumor cell survival using the maximum a posteriori or the expected tumor cell density. We show how our method allows the user to compute a patient specific radiotherapy planning conformal to the tumor infiltration. We further present extensions of the method in order to spare adjacent organs at risk by re-distributing the dose. The presented approach and its proof of concept may help in the future to better target the tumor and spare organs at risk.

The survival significance of a measurable enhancing lesion after completing standard treatment for newly diagnosed glioblastoma

The goal of this study was to analyze the survival outcome according to the treatment response after completing standard treatment protocol for newly diagnosed glioblastoma (GBM) and to suggest a patient who should be considered for further treatment. After approving by our Institutional Review Board, 57 patients (38 male, 19 female; median age, 52years; age range, 16-81years) with newly diagnosed GBM who completed standard treatment protocol were examined retrospectively. According to the treatment response using the RANO criteria, there were 20 patients with complete response (CR), five patients with partial response (PR), 13 patients with stable disease (SD) and 19 patients with progressive disease (PD) after the completion of standard treatment. Patients (PR+SD+PD) with a measurable enhancing lesion were categorized the MEL group (n=37). We analyzed the difference of survival outcome between CR group and MEL group. The median progression-free survival (PFS) in the CR group was significantly better than that of the MEL group (18.0months vs. 3.0months, p=0.004). The median overall survival (OS) was also significantly longer in the CR group (25.0months vs. 15.0months, p=0.005). However, there was no significant difference in the survival outcome of the CR group compared with that of the subset of MEL group patients who showed PR or SD. Poor survival outcome was found only in MEL group patients who exhibited progression. Patients with a measurable enhancing lesion showing progression after completion of standard treatment protocol are appropriate candidates for further treatment.

Relapse patterns after radiochemotherapy of glioblastoma with FET PET-guided boost irradiation and simulation to optimize radiation target volume

Background

O-(2-18 F-fluoroethyl)-L-tyrosine-(FET)-PET may be helpful to improve the definition of radiation target volumes in glioblastomas compared with MRI. We analyzed the relapse patterns in FET-PET after a FET- and MRI-based integrated-boost intensity-modulated radiotherapy (IMRT) of glioblastomas to perform an optimized target volume definition.

Methods

A relapse pattern analysis was performed in 13 glioblastoma patients treated with radiochemotherapy within a prospective phase-II-study between 2008 and 2009. Radiotherapy was performed as an integrated-boost intensity-modulated radiotherapy (IB-IMRT). The prescribed dose was 72 Gy for the boost target volume, based on baseline FET-PET (FET-1) and 60 Gy for the MRI-based (MRI-1) standard target volume. The single doses were 2.4 and 2.0 Gy, respectively. Location and volume of recurrent tumors in FET-2 and MRI-2 were analyzed related to initial tumor, detected in baseline FET-1. Variable target volumes were created theoretically based on FET-1 to optimally cover recurrent tumor.

Results

The tumor volume overlap in FET and MRI was poor both at baseline (median 12 %; range 0–32) and at time of recurrence (13 %; 0–100). Recurrent tumor volume in FET-2 was localized to 39 % (12–91) in the initial tumor volume (FET-1). Over the time a shrinking (mean 12 (5–26) ml) and shifting (mean 6 (1–10 mm) of the resection cavity was seen. A simulated target volume based on active tumor in FET-1 with an additional safety margin of 7 mm around the FET-1 volume covered recurrent FET tumor volume (FET-2) significantly better than a corresponding target volume based on contrast enhancement in MRI-1 with a same safety margin of 7 mm (100 % (54–100) versus 85 % (0–100); p < 0.01). A simulated planning target volume (PTV), based on FET-1 and additional 7 mm margin plus 5 mm margin for setup-uncertainties was significantly smaller than the conventional, MR-based PTV applied in this study (median 160 (112–297) ml versus 231 (117–386) ml, p < 0.001).

Conclusions

In this small study recurrent tumor volume in FET-PET (FET-2) overlapped only to one third with the boost target volume, based on FET-1. The shrinking and shifting of the resection cavity may have an influence considering the limited overlap of initial and relapse tumor volume. A simulated target volume, based on FET-1 with 7 mm margin covered 100 % of relapse volume in median and led to a significantly reduced PTV, compared to MRI-based PTVs. This approach may achieve similar therapeutic efficacy but lower side effects offering a broader window to intensify concomitant systemic treatment focusing distant failures.

Sampling image segmentations for uncertainty quantification

In this paper, we introduce a method to automatically produce plausible image segmentation samples from a single expert segmentation. A probability distribution of image segmentation boundaries is defined as a Gaussian process, which leads to segmentations which are spatially coherent and consistent with the presence of salient borders in the image. The proposed approach is computationally efficient, and generates visually plausible samples. The variability between the samples is mainly governed by a parameter which may be correlated with a simple Dice's coefficient, or easily set by the user from the definition of probable regions of interest. The method is extended to the case of several neighboring structures, but also to account for under or over segmentation, and the presence of excluded regions. We also detail a method to sample segmentations with more general non-stationary covariance functions which relies on supervoxels. Furthermore, we compare the generated segmentation samples with several manual clinical segmentations of a brain tumor. Finally, we show how this approach can have useful applications in the field of uncertainty quantification, and an illustration is provided in radiotherapy planning, where segmentation sampling is applied to both the clinical target volume and the organs at risk.

The potential impact of delayed radiation therapy on patients with glioblastoma

BACKGROUND

Radiation therapy (RT) is the major component of glioblastoma treatment; however, the time to initiate RT after surgical intervention varies between institutions. Our study examined the time from diagnosis to the initiation of RT and its effects on overall patient survival.

METHODS

We retrospectively examined 267 patients with glioblastoma who received RT as part of their therapy in two Canadian tertiary care centers. The primary goal of the study is to assess if time to RT can predict/impact survival in glioblastoma patients.

RESULTS

The following variables were associated with an increased risk of death: hazard ratio (HR) of time to RT was 0.95 [95% confidence interval (CI), 0.91–0.99] for every extra week. HRs for the type of surgery (resection or biopsy) and type of management received (standard of care in comparison with RT regardless of chemotherapeutic agents other than concomitant and adjuvant temozolomide) were 0.50 (95% CI, 0.37–0.66) and 0.53 (95% CI, 0.38–0.75), respectively. HR for age was 1.02 (95% CI, 1.01–1.03) for every extra year. Standard 60 Gy RT HR was 0.70 [95% confidence interval (CI), 0.51–0.97] in younger patients.

CONCLUSIONS

The time from diagnosis to the initiation of RT was found to be a significant prognostic factor for overall patient survival. The addition of temozolomide to the treatment protocol, age, standard RT dose in younger patients and extent of surgery are others factors associated with longer survival periods.

Impact potentiel de la radiothérapie différée chez les patients atteints d'un glioblastome.

Pro-apoptotic and anti-angiogenic properties of the α /β-thujone fraction from Thuja occidentalis on glioblastoma cells

The most aggressive type of brain tumor is glioblastoma multiforme, which to date remains incurable. Thuja occidentalis is used in homeopathy for the treatment of cancer, however, its mechanism of action remains unknown. We set out to study the effects of thujone fractions of Thuja on glioblastoma using in vitro and in vivo models. We found that the α/ β-thujone fraction decrease the cell viability and exhibit a potent anti-proliferative, pro-apoptotic and anti-angiogenic effects in vitro. In vivo assays showed that α /β-thujone promotes the regression of neoplasia and inhibits the angiogenic markers VEGF, Ang-4 and CD31 into the tumor.

Glioblastoma: Radiation treatment margins, how small is large enough?

Standard treatment for glioblastoma consists of surgical resection followed by radiation therapy with concurrent and adjuvant chemotherapy. Conventional radiation clinical treatment volumes include a 2- to 3-cm margin around magnetic resonance imaging or computed tomography enhancing abnormalities in the brain as well as a margin around the T2 or fluid-attenuated inversion recovery abnormality. However, there remains significant variability with respect to whether such extensive margins are necessary. Collectively, we as authors of this manuscript also use different margins, with A.G.W. employing European Organization for Research and Treatment of Cancer recommendations of a 2- to 3-cm margin on T1 enhancement for 60 Gy and M.P.M. using Radiation Therapy Oncology Group recommendations of 2 cm on T2 signal abnormality for the initial 46 Gy and 2.5-cm margin on T1 enhancement for a 14-Gy boost. Our experiences reflect the heterogeneity of margin definition and selection for this disease and underscore an important area of further research to minimize this variability. In this article, we review studies exploring recurrence patterns and outcomes in patients treated using both conventional and more limited margins. We conclude that treating to "smaller" margins does not alter recurrence patterns nor does it result in inferior survival, but whether this is because of the inherently limited benefit of radiation therapy in the first place, or whether it is truly because microscopic tumor control at larger distances is not an issue, remains unestablished.

Expression and mutation analysis of Cyclin A and Ki-67 in glioma and their correlation with tumor progression

The present study aimed to analyze the expression and mutation of Cyclin A and Ki-67 in gliomas, and determine their correlation with tumor progression. Tissue samples of 186 diagnosed glioma patients were examined immunohistochemically for Cyclin A and Ki-67 expression. Gene mutation analysis was performed on genomic DNA extracted from patient samples, using polymerase chain reaction amplification and sequencing. Cyclin A and Ki-67 expression were observed in the glioma and lymphatic metastasis tissues, and were analyzed using SPSS 14.0 statistical software. Of the total patients, 64 (34.41%) were Cyclin A-positive and 68 (36.56%) were Ki-67-positive. The expression of Cyclin A and Ki-67 in glioma was positively correlated with lymphatic metastasis. Statistically significant differences were observed in the mutation rate of Ki-67 (P<0.05), but not Cyclin A (P>0.05), between the gliomas and metastatic tumors. In conclusion, Cyclin A and Ki-67 are highly expressed in glioma tissues, and their expression and mutation are associated with the lymphatic metastasis of glioma in the brain. It may be concluded that Cyclin A and Ki-67 may be used as biomarkers to guide the diagnosis of glioma and evaluate the prognosis of affected patients.

Proficiency performance benchmarks for removal of simulated brain tumors using a virtual reality simulator NeuroTouch

OBJECTIVE

Assessment of neurosurgical technical skills involved in the resection of cerebral tumors in operative environments is complex. Educators emphasize the need to develop and use objective and meaningful assessment tools that are reliable and valid for assessing trainees' progress in acquiring surgical skills. The purpose of this study was to develop proficiency performance benchmarks for a newly proposed set of objective measures (metrics) of neurosurgical technical skills performance during simulated brain tumor resection using a new virtual reality simulator (NeuroTouch).

DESIGN

Each participant performed the resection of 18 simulated brain tumors of different complexity using the NeuroTouch platform. Surgical performance was computed using Tier 1 and Tier 2 metrics derived from NeuroTouch simulator data consisting of (1) safety metrics, including (a) volume of surrounding simulated normal brain tissue removed, (b) sum of forces utilized, and (c) maximum force applied during tumor resection; (2) quality of operation metric, which involved the percentage of tumor removed; and (3) efficiency metrics, including (a) instrument total tip path lengths and (b) frequency of pedal activation.

SETTING

All studies were conducted in the Neurosurgical Simulation Research Centre, Montreal Neurological Institute and Hospital, McGill University, Montreal, Canada.

PARTICIPANTS

A total of 33 participants were recruited, including 17 experts (board-certified neurosurgeons) and 16 novices (7 senior and 9 junior neurosurgery residents).

RESULTS

The results demonstrated that "expert" neurosurgeons resected less surrounding simulated normal brain tissue and less tumor tissue than residents. These data are consistent with the concept that "experts" focused more on safety of the surgical procedure compared with novices. By analyzing experts' neurosurgical technical skills performance on these different metrics, we were able to establish benchmarks for goal proficiency performance training of neurosurgery residents.

CONCLUSION

This study furthers our understanding of expert neurosurgical performance during the resection of simulated virtual reality tumors and provides neurosurgical trainees with predefined proficiency performance benchmarks designed to maximize the learning of specific surgical technical skills.

Expression of TYMS in lymph node metastasis from low-grade glioma

The aim of the present study was to investigate the expression of thymidylate synthase (TYMS) in the primary foci and metastatic lymph nodes of low-grade glioma, and to analyze the function of TYMS in the lymph node metastases from low-grade glioma. The study included 93 cases of surgically resected and pathologically confirmed low-grade glioma, form patients treated at Huaihe Hospital of Henan University (Kaifeng, China). The following clinical data was obtained from each patient: Gender, age, subjective symptoms (dizziness, headache, a feeling of pressure in the head, etc.), site of disease, tumor type, pathological stage, degree of differentiation and lymph node involvement. The surgically resected gliomas and dissected cervical lymph nodes were immunohistochemically stained, and DNA was extracted from the tumor and lymph node tissues samples for polymerase chain reaction sequencing and amplification. The expression of TYMS in the primary foci and metastatic lymph nodes of low-grade glioma was examined. Additionally, the association between pathological features and the postoperative survival rate of the patients was analyzed. The primary lesions of all 93 cases exhibited positive TYMS expression and 43/157 (27.39%) lymph nodes exhibited positive TYMS expression. Factors that significantly influenced the postoperative survival rate of the patients, included the metastasis of the cervical lymph nodes (P<0.01), the number of dissected cervical lymph nodes (P<0.01) and the degree of differentiation (P<0.05). The metastasis of the cervical lymph nodes was the only independent risk factor affecting postoperative disease-free survival. The risk of recurrence in patients with metastasis of the cervical lymph nodes was 6.3-fold higher than in those without metastasis (P<0.01). Thus, the results of the present study provide a theoretical basis for accurately predicting the prognosis of patients with low-grade malignant brain glioma, reducing the conjecture involved in selecting postoperative treatment strategies and improving therapeutic efficacy.

Standardization and quality assurance of radiation therapy volumes for adults with high-grade gliomas

Standard treatment for Glioblastoma Multiforme (GBM) consists of a combination of chemotherapy and radiation therapy followed by adjuvant chemotherapy. While the optimal dose of radiation therapy has been established, significant variability in volume of tissue irradiated exists. In this article we review the current guidelines, patterns of care, patterns of failure, imaging advances and toxicity related to radiation therapy volumes in the treatment of GBM.

Phase II study of PX-866 in recurrent glioblastoma

BACKGROUND

Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system in adults. Increased activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway is common. We performed a phase II study using PX-866, an oral PI3K inhibitor, in participants with recurrent GBM.

METHODS

Patients with histologically confirmed GBM at first recurrence were given oral PX-866 at a dose of 8 mg daily. An MRI and clinical exam were done every 8 weeks. Tissue was analyzed for potential predictive markers.

RESULTS

Thirty-three participants (12 female) were enrolled. Median age was 56 years (range 35-78y). Eastern Cooperative Oncology Group performance status was 0-1 in 29 participants and 2 in the remainder. Median number of cycles was 1 (range 1-8). All participants have discontinued therapy: 27 for disease progression and 6 for toxicity (5 liver enzymes and 1 allergic reaction). Four participants had treatment-related serious adverse events (1 liver enzyme, 1 diarrhea, 2 venous thromboembolism). Other adverse effects included fatigue, diarrhea, nausea, vomiting, and lymphopenia. Twenty-four participants had a response of progression (73%), 1 had partial response (3%, and 8 (24%) had stable disease (median, 6.3 months; range, 3.1-16.8 months). Median 6-month progression-free survival was 17%. None of the associations between stable disease and PTEN, PIK3CA, PIK3R1, or EGFRvIII status were statistically significant.

CONCLUSIONS

PX-866 was relatively well tolerated. Overall response rate was low, and the study did not meet its primary endpoint; however, 21% of participants obtained durable stable disease. This study also failed to identify a statistically significant association between clinical outcome and relevant biomarkers in patients with available tissue.

Clinical practice guidelines and consensus statements in oncology--an assessment of their methodological quality

BACKGROUND

Consensus statements and clinical practice guidelines are widely available for enhancing the care of cancer patients. Despite subtle differences in their definition and purpose, these terms are often used interchangeably. We systematically assessed the methodological quality of consensus statements and clinical practice guidelines published in three commonly read, geographically diverse, cancer-specific journals. Methods Consensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine's standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.

METHODS

Consensus statements and clinical practice guidelines published between January 2005 and September 2013 in Current Oncology, European Journal of Cancer and Journal of Clinical Oncology were evaluated. Each publication was assessed using the Appraisal of Guidelines for Research and Evaluation II (AGREE II) rigour of development and editorial independence domains. For assessment of transparency of document development, 7 additional items were taken from the Institute of Medicine's standards for practice guidelines and the Journal of Clinical Oncology guidelines for authors of guidance documents.

FINDINGS

Thirty-four consensus statements and 67 clinical practice guidelines were evaluated. The rigour of development score for consensus statements over the three journals was 32% lower than that of clinical practice guidelines. The editorial independence score was 15% lower for consensus statements than clinical practice guidelines. One journal scored consistently lower than the others over both domains. No journals adhered to all the items related to the transparency of document development. One journal's consensus statements endorsed a product made by the sponsoring pharmaceutical company in 64% of cases.

CONCLUSION

Guidance documents are an essential part of oncology care and should be subjected to a rigorous and validated development process. Consensus statements had lower methodological quality than clinical practice guidelines using AGREE II. At a minimum, journals should ensure that that all consensus statements and clinical practice guidelines adhere to AGREE II criteria. Journals should consider explicitly requiring guidelines to declare pharmaceutical company sponsorship and to identify the sponsor's product to enhance transparency.

Quality appraisal of clinical practice guidelines on glioma

Clinical practice guidelines (CPGs) play an important role in healthcare. The guideline development process should be precise and rigorous to ensure that the results are reproducible and not vague. To determine the quality of guidelines, the Appraisal of Guidelines and Research and Evaluation (AGREE) instrument was developed and introduced. The aim of the present study was to assess the methodological quality of clinical practice guidelines on glioma. Eight databases (including MEDLINE and Embase) were searched till to August, 2013. The methodological quality of the guidelines was assessed by four authors independently using the AGREE II instrument. Fifteen relevant guidelines were included from 940 citations. The overall agreement among reviewers was moderate (intra-class correlation coefficient = 0.83; 95% confidence interval [CI], 0.66-0.92). The mean scores were moderate for the domains "scope and purpose" (59.54) and "clarity of presentation" (65.46); however, there were low scores for the domains "stakeholder involvement" (43.80), "rigor of development" (39.01), "applicability" (31.89), and "editorial independence" (30.83). Only one third of the guidelines described the systematic methods for searching, and nearly half of the (47%) guidelines did not give a specific recommendation. Only four of 15 described a procedure for updating the guideline; meanwhile, just six guidelines in this field can be considered to be evidence-based. The quality and transparency of the development process and the consistency in the reporting of glioma guidelines need to be improved. And the quality of reporting of guidelines was disappointing. Many other methodological disadvantages were identified. In the future, glioma CPGs should be based on the best available evidence and rigorously developed and reported. Greater efforts are needed to provide high-quality guidelines that serve as a useful and reliable tool for clinical decision-making in this field.

Metabolic therapy: a new paradigm for managing malignant brain cancer

Little progress has been made in the long-term management of glioblastoma multiforme (GBM), considered among the most lethal of brain cancers. Cytotoxic chemotherapy, steroids, and high-dose radiation are generally used as the standard of care for GBM. These procedures can create a tumor microenvironment rich in glucose and glutamine. Glucose and glutamine are suggested to facilitate tumor progression. Recent evidence suggests that many GBMs are infected with cytomegalovirus, which could further enhance glucose and glutamine metabolism in the tumor cells. Emerging evidence also suggests that neoplastic macrophages/microglia, arising through possible fusion hybridization, can comprise an invasive cell subpopulation within GBM. Glucose and glutamine are major fuels for myeloid cells, as well as for the more rapidly proliferating cancer stem cells. Therapies that increase inflammation and energy metabolites in the GBM microenvironment can enhance tumor progression. In contrast to current GBM therapies, metabolic therapy is designed to target the metabolic malady common to all tumor cells (aerobic fermentation), while enhancing the health and vitality of normal brain cells and the entire body. The calorie restricted ketogenic diet (KD-R) is an anti-angiogenic, anti-inflammatory and pro-apoptotic metabolic therapy that also reduces fermentable fuels in the tumor microenvironment. Metabolic therapy, as an alternative to the standard of care, has the potential to improve outcome for patients with GBM and other malignant brain cancers.

Acute ischemic stroke secondary to glioblastoma. A case report

Glioblastoma is a malignant infiltrative glial tumor occurring most often over 50 years of age, with diverse clinical presentations. We describe a case of temporal lobe glioblastoma with a rare presentation as an acute ischemic stroke, discussing the imaging and histopathological findings, and reviewing the literature. A 77-year-old woman had sudden onset of left hemiparesis and hemihypoesthesia. The neuroradiological studies revealed an acute ischemic lesion in the right lenticulostriate arteries territory and a right anterior temporal lobe tumor, enhancing heterogeneously after contrast with enhancement of the right middle cerebral artery wall. Histopathological analysis of the resected temporal lesion revealed a glioblastoma multiforme with tumoral infiltration of the vascular wall. Glioblastoma should be considered in the etiology of acute ischemic stroke, where neuroimaging plays an important diagnostic role, enabling a more immediate therapeutic approach, with a consequent impact on survival.

Restricted calorie ketogenic diet for the treatment of glioblastoma multiforme

Glioblastoma multiforme is the most common malignant primary brain tumor in adults and generally considered to be universally fatal. Glioblastoma multiforme accounts for 12% to 15% of all intracranial neoplasms and affects 2 to 3 adults per every 100,000 in the United States annually. In children glioblastoma multiforme accounts for only approximately 7% to 9% of central nervous system tumors. The mean survival rate in adults after diagnosis ranges from 12 to 18 months with standard therapy and 3 to 6 months without therapy. The prognosis in children is better compared to adult tumor onset with a mean survival of approximately 4 years following gross total surgical resection and chemotherapy. There have been few advances in the treatment of glioblastoma multiforme in the past 40 years beyond surgery, radiotherapy, chemotherapy, and corticosteroids. For this reason a restrictive calorie ketogenic diet, similar to that used in children to control drug resistant seizure activity, has been advanced as an alternative adjunctive treatment to help prolonged survival. This article reviews the science of tumor metabolism and discusses the mechanism of calorie restriction, cellular energy metabolism, and how dietary induced ketosis can inhibit cancer cell's energy supply to slow tumor growth.

Calcineurin regulates nuclear factor I dephosphorylation and activity in malignant glioma cell lines

Malignant gliomas (MG), including grades III and IV astrocytomas, are the most common adult brain tumors. These tumors are highly aggressive with a median survival of less than 2 years. Nuclear factor I (NFI) is a family of transcription factors that regulates the expression of glial genes in the developing brain. We have previously shown that regulation of the brain fatty acid-binding protein (B-FABP; FABP7) and glial fibrillary acidic protein (GFAP) genes in MG cells is dependent on the phosphorylation state of NFI, with hypophosphorylation of NFI correlating with GFAP and B-FABP expression. Importantly, NFI phosphorylation is dependent on phosphatase activity that is enriched in GFAP/B-FABP+ve cells. Using chromatin immunoprecipitation, we show that NFI occupies the GFAP and B-FABP promoters in NFI-hypophosphorylated GFAP/B-FABP+ve MG cells. NFI occupancy, NFI-dependent transcriptional activity, and NFI phosphorylation are all modulated by the serine/threonine phosphatase calcineurin. Importantly, a cleaved form of calcineurin, associated with increased phosphatase activity, is specifically expressed in NFI-hypophosphorylated GFAP/B-FABP+ve MG cells. Calcineurin in GFAP/B-FABP+ve MG cells localizes to the nucleus. In contrast, calcineurin is primarily found in the cytoplasm of GFAP/B-FABP-ve cells, suggesting a dual mechanism for calcineurin activation in MG. Finally, our results demonstrate that calcineurin expression is up-regulated in areas of high infiltration/migration in grade IV astrocytoma tumor tissue. Our data suggest a critical role for calcineurin in NFI transcriptional regulation and in the determination of MG infiltrative properties.

Should we continue temozolomide beyond six cycles in the adjuvant treatment of glioblastoma without an evidence of clinical benefit? A cost analysis based on prescribing patterns in Spain

PURPOSE

The standard adjuvant treatment for glioblastoma is temozolomide concomitant with radiotherapy, followed by a further six cycles of temozolomide. However, due to the lack of empirical evidence and international consensus regarding the optimal duration of temozolomide treatment, it is often extended to 12 or more cycles, even in the absence of residual disease. No clinical trial has shown clear evidence of clinical benefit of this extended treatment. We have explored the economic impact of this practice in Spain.

MATERIALS AND METHODS

Spanish neuro-oncologists completed a questionnaire on the clinical management of glioblastomas in their centers. Based on their responses and on available clinical and demographic data, we estimated the number of patients who receive more than six cycles of temozolomide and calculated the cost of this extended treatment.

RESULTS

Temozolomide treatment is continued for more than six cycles by 80.5 % of neuro-oncologists: 44.4 % only if there is residual disease; 27.8 % for 12 cycles even in the absence of residual disease; and 8.3 % until progression. Thus, 292 patients annually will continue treatment beyond six cycles in spite of a lack of clear evidence of clinical benefit. Temozolomide is covered by the National Health Insurance System, and the additional economic burden to society of this extended treatment is nearly 1.5 million euros a year.

CONCLUSIONS

The optimal duration of adjuvant temozolomide treatment merits investigation in a clinical trial due to the economic consequences of prolonged treatment without evidence of greater patient benefit.

Pseudoprogression of glioblastoma after chemo- and radiation therapy: diagnosis by using dynamic susceptibility-weighted contrast-enhanced perfusion MR imaging with ferumoxytol versus gadoteridol and correlation with survival

PURPOSE

To compare gadoteridol and ferumoxytol for measurement of relative cerebral blood volume (rCBV) in patients with glioblastoma multiforme (GBM) who showed progressive disease at conventional magnetic resonance (MR) imaging after chemo- and radiation therapy (hereafter, chemoradiotherapy) and to correlate rCBV with survival.

MATERIALS AND METHODS

Informed consent was obtained from all participants before enrollment in one of four institutional review board-approved protocols. Contrast agent leakage maps and rCBV were derived from perfusion MR imaging with gadoteridol and ferumoxytol in 19 patients with apparently progressive GBM on conventional MR images after chemoradiotherapy. Patients were classified as having high rCBV (>1.75), indicating tumor, and low rCBV (≤ 1.75), indicating pseudoprogression, for each contrast agent separately, and with or without contrast agent leakage correction for imaging with gadoteridol. Statistical analysis was performed by using Kaplan-Meier survival plots with the log-rank test and Cox proportional hazards models.

RESULTS

With ferumoxytol, rCBV was low in nine (47%) patients, with median overall survival (mOS) of 591 days, and high rCBV in 10 (53%) patients, with mOS of 163 days. A hazard ratio of 0.098 (P = .004) indicated significantly improved survival. With gadoteridol, rCBV was low in 14 (74%) patients, with mOS of 474 days, and high in five (26%), with mOS of 156 days and a nonsignificant hazard ratio of 0.339 (P = .093). Five patients with mismatched high rCBV with ferumoxytol and low rCBV with gadoteridol had an mOS of 171 days. When leakage correction was applied, rCBV with gadoteridol was significantly associated with survival (hazard ratio, 0.12; P = .003).

CONCLUSION

Ferumoxytol as a blood pool agent facilitates differentiation between tumor progression and pseudoprogression, appears to be a good prognostic biomarker, and unlike gadoteridol, does not require contrast agent leakage correction.

Does extent of resection impact survival in patients bearing glioblastoma?

BACKGROUND

The impact of malignant glioma resection on survival is still a matter of controversy. The lack of well-designed prospective studies as well as control of all factors in retrospective studies plays an important role in this debate. Amongst some of these uncontrolled factors, are the inclusion of different histological grades, the lack of objective methods to estimate the extent of resection and unspecified delays in post-operative imaging.

METHODS

We retrospectively reviewed 126 consecutive patients with glioblastoma, operated on by the senior authors at the Centre Hospitalier Universitaire de Sherbrooke, who met the following criteria: >18 years of age, newly diagnosed glioblastoma, pre-operative magnetic resonance imaging (MRI) within 2 weeks prior to surgery, and a post-operative MRI within 72 hours after surgery. Extent of tumour resection was calculated using pre and post-operative tumour delimitation on gadolinium-enhanced T1 MRI in a volumetric analysis.

RESULTS

Applying stringent specific inclusion criteria, 126 patients were retained in the analysis. The median overall survival was 271 days and the median extent of resection was 65%. Patients with more than 90% of tumour resection had a significantly better outcome, improving median survival from 225 to 519 days (P=0.006). Other factors that significantly improved survival were the use of radiotherapy, the number of regimens and type of chemotherapy used.

CONCLUSION

A more aggressive approach combining maximal safe resection and use of salvage chemotherapy seems to confer a survival advantage for glioblastoma patients.

Canadian recommendations for the treatment of recurrent or progressive glioblastoma multiforme

Recommendation 1: Multidisciplinary ApproachTo optimize treatment outcomes, the management of patients with recurrent glioblastoma should be individualized and should involve a multidisciplinary team approach, including neurosurgery, neuropathology, radiation oncology, neuro-oncology, and allied health professions.Recommendation 2: ImagingThe standard imaging modality for assessment of recurrent glioblastoma is Gd-enhanced magnetic resonance imaging (mri). Tumour recurrence should be assessed according to the criteria set out by the Response Assessment in Neuro-Oncology Working Group. The optimal timing and frequency of mri after chemoradiation and adjunctive therapy have not been established.Recommendation 3: Pseudo-progressionProgression observed by mri after chemoradiation can be pseudo-progression. Accordingly, treated patients should not be classified as having progressive disease by Gd-enhancing mri within the first 12 weeks after the end of radiotherapy unless new enhancement is observed outside the radiotherapy field or viable tumour is confirmed by pathology at the time of a required re-operation. Adjuvant temozolomide should be continued and follow-up imaging obtained.Recommendation 4: Repeat SurgerySurgery can play a role in providing symptom relief and confirming tumour recurrence, pseudo-progression, or radiation necrosis. However, before surgical intervention, it is essential to clearly define treatment goals and the expected impact on prognosis and the patient's quality of life. In the absence of level 1 evidence, the decision to re-operate should be made according to individual circumstances, in consultation with the multidisciplinary team and the patient.Recommendation 5: Re-irradiationRe-irradiation is seldom recommended, but can be considered in carefully selected cases of recurrent glioblastoma.Recommendation 6: Systemic TherapyClinical trials, when available, should be offered to all eligible patients. In the absence of a trial, systemic therapy, including temozolomide rechallenge or anti-angiogenic therapy, may be considered. Combination therapy is still experimental; optimal drug combinations and sequencing have not been established.

Secondary gliosarcoma after the treatment of primary glioblastoma multiforme

Context:

Gliosarcoma is a rare variant of glioblastoma multiforme containing distinct gliomatous and sarcomatous components. Gliosarcoma comprise 1.8–8% of glioblastoma multiforme and are clinically similar to them, affecting adults in the fourth and sixth decades of life, with a higher proportion found in males. The survival for patients with Gliosarcoma is equally poor as for those with glioblastoma multiforme, and there is a greater propensity for extracranial metastasis in Gliosarcoma. Clinical treatment-related experience reported in the literature is limited, and Gliosarcoma are currently treated in a similar fashion to glioblastoma multiforme, with modalities including tumor resection, postoperative radiation therapy, and chemotherapy. Gliosarcoma can arise secondarily, after conventional adjuvant treatment of high-grade glioma. The current literature on the occurrence of secondary gliosarcoma after glioblastoma multiforme is limited, with only 54 reported cases.

Case Report:

The authors present a 48-year-old Caucasian male who had previously received postoperative combined radiation and temozolomide chemotherapy for glioblastoma multiforme. After a free disease period of 9 months the disease recurs as Gliosarcoma. The patient underwent a Total surgical excision and received chemotherapy with a basis of bevacizumab and irinotecan. The patient died from tumor progression 5 months after gliosarcoma diagnosis.

Conclusion:

The poor survival of patients with secondary gliosarcoma who had previously received combined radiation and temozolomide chemotherapy for glioblastoma multiforme may reflect a unique molecular profile of glioblastoma multiforme that eventually recurs as secondary gliosarcoma. We have to keep in mind the possibility of gliosarcomatous change in the recurrence of malignant glioma. Awareness of this pathological entity will allow more rapid diagnosis and treatment.

Does neurologic deterioration help to differentiate between pseudoprogression and true disease progression in newly diagnosed glioblastoma multiforme?

Enlarging or new lesions frequently appear on magnetic resonance imaging (mri) after concurrent administration of radiation therapy and temozolomide in glioblastoma multiforme (gbm) patients. However, in nearly half such cases, the observed radiologic changes are not due to true disease progression, but instead are a result of a post-radiation inflammatory state called "pseudoprogression." Retrospective studies have reported that neurologic deterioration at the time of the post-chemoradiotherapy mri is found more commonly in patients with true disease progression. We report a gbm patient with both radiologic progression on the post-chemoradiotherapy mri and concomitant neurologic deterioration, and we caution against incorporating clinical deterioration into the management schema of patients with possible pseudoprogression.

Temozolomide and other potential agents for the treatment of glioblastoma multiforme

This article provides historical and recent perspectives related to the use of temozolomide for the treatment of glioblastoma multiforme. Temozolomide has quickly become part of the standard of care for the modern treatment of stage IV glioblastoma multiforme since its approval in 2005. Yet despite its improvements from previous therapies, median survival remains approximately 15 months, with a 2-year survival rate of 8% to 26%. The mechanism of action of this chemotherapeutic agent, conferred advantages and limitations, treatment resistance and rescue, and potential targets of future research are discussed.