Management of newly diagnosed glioblastoma: guidelines development, value and application

Congress of neurological surgeons systematic review and evidence-based guidelines update on the role of neuropathology in the management of progressive glioblastoma in adults

TARGET POPULATION

These recommendations apply to adult patients with progressive or recurrent glioblastoma (GBM).

QUESTION

For adult patients with progressive glioblastoma does testing for Isocitrate Dehydrogenase (IDH) 1 or 2 mutations provide new additional management or prognostic information beyond that derived from the tumor at initial presentation?

RECOMMENDATION

Level III: Repeat IDH mutation testing is not necessary if the tumor is histologically similar to the primary tumor and the patient's clinical course is as expected.

QUESTION

For adult patients with progressive glioblastoma does repeat testing for MGMT promoter methylation provide new or additional management or prognostic information beyond that derived from the tumor at initial presentation and what methods of detection are optimal?

RECOMMENDATION

Level III: Repeat MGMT promoter methylation is not recommended.

QUESTION

For adult patients with progressive glioblastoma does EGFR amplification or mutation testing provide management or prognostic information beyond that provided by histologic analysis and if performed on previous tissue samples, does it need to be repeated?

RECOMMENDATION

Level III: In cases that are difficult to classify as glioblastoma on histologic features EGFR amplification testing may help in classification. If a previous EGFR amplification was detected, repeat testing is not necessary. Repeat EGFR amplification or mutational testing may be recommended in patients in which target therapy is being considered.

QUESTION

For adult patients with progressive glioblastoma does large panel or whole genome sequencing provide management or prognostic information beyond that derived from histologic analysis?

RECOMMENDATION

Level III: Primary or repeat large panel or whole genome sequencing may be considered in patients who are eligible or interested in molecularly guided therapy or clinical trials.

QUESTION

For adult patients with progressive glioblastoma should immune checkpoint biomarker testing be performed to provide management and prognostic information beyond that obtained from histologic analysis?

RECOMMENDATION

Level III: The current evidence does not support making PD-L1 or mismatch repair (MMR) enzyme activity a component of standard testing.

QUESTION

For adult patients with progressive glioblastoma are there meaningful biomarkers for bevacizumab responsiveness and does their assessment provide additional information for tumor management and prognosis beyond that learned by standard histologic analysis?

RECOMMENDATION

Level III: No established Bevacizumab biomarkers are currently available based upon the inclusion criteria of this guideline.

Progesterone Is More Effective Than Dexamethasone in Prolonging Overall Survival and Preserving Neurologic Function in Experimental Animals with Orthotopic Glioblastoma Allografts

OBJECTIVE

Dexamethasone (DEXA) has been widely used in the management of peritumoral brain edema. DEXA, however, has many systemic side effects and can interact negatively with glioma therapy. Progesterone (PROG), however, is a well-tolerated and readily accessible anti-inflammatory and antiedema agent, with potent neuroprotective properties. We investigated whether PROG could serve as a viable alternative to DEXA in the management of peritumoral brain edema.

METHODS

We used an orthotopic C6 glioblastoma model with male Sprague-Dawley rats. Tumor grafts were allowed to grow for 14 days before drug treatment with DEXA 1 mg/kg, PROG 10 mg/kg, or PROG 20 mg/kg for 5 consecutive days. The overall animal survival and neurologic function were evaluated. Mechanistic studies on blood-brain barrier permeability and angiogenic responses were performed on the ex vivo tumor grafts.

RESULTS

We found that all drug treatments prolonged overall survival to different extents. PROG 10 mg led to significantly longer survival and better preservation of neurologic function and body weight. The blood-brain barrier permeability was better preserved with PROG 10 mg than with DEXA, possibly through downregulation of matrix metalloproteinase-9 and aquaporin-4 expression. Antiangiogenic responses were also observed in the PROG group.

CONCLUSIONS

The present proof-of-concept pilot study has provided novel information on the use of PROG as a corticosteroid-sparing agent in brain tumor management. Further translational and clinical studies are warranted.

Using Smaller-Than-Standard Radiation Treatment Margins Does Not Change Survival Outcomes in Patients with High-Grade Gliomas

PURPOSE

The number of studies that evaluate treatment margins for high grade gliomas (HGG) are limited. We hypothesize that patients with HGG who are treated with a gross tumor volume (GTV) to planning tumor volume (PTV) expansion of ≤1 cm will have progression-free survival (PFS) and overall survival (OS) rates similar to those treated in accordance with standard protocols by the Radiation Therapy Oncology Group or European Organisation for Research and Treatment of Cancer. Furthermore, the PFS and OS of subgroups within the study population will have equivalent survival outcomes with GTV1-to-PTV1 margins of 1.0 cm and 0.4 cm.

METHODS AND MATERIALS

Treatment plans and outcomes for patients with pathologically confirmed HGG were analyzed (n = 267). Survival (PFS and OS) was calculated from the time of the first radiation treatment and a χ² test or Fisher exact test was used to calculate the associations between margin size and patient characteristics. Survival was estimated using Kaplan-Meier and compared using the log-rank test. All analyses were performed on the univariate level.

RESULTS

The median PFS and OS times were 10.6 and 19.1 months, respectively. By disease, the median PFS and OS times were 8.6 and 16.1 months for glioblastoma and 26.7 and 52.5 months for anaplastic glioma. The median follow-up time was 18.3 months. The treatment margin had no effect on outcome and the 1.0 cm GTV1-PTV1 margin subgroup (n = 212) showed median PFS and OS times of 10.7 and 19.1 months, respectively, and the 0.4 cm margin subgroup (n = 55) 10.2 and 19.3 months, respectively. In comparison with the standard treatment with 2 cm to 3 cm margins, there was not a significant difference in outcomes.

CONCLUSIONS

There is no apparent difference in survival when utilizing smaller versus larger margins as defined by the guidelines of the Radiation Therapy Oncology Group and European Organisation for Research and Treatment of Cancer. Although there remains no class I evidence that outcomes after treatment with smaller margins are identical to those after treatment with larger margins, this large series with long-term follow up suggests that a reduction of the margins is safe and further investigation is warranted.

Glioblastoma (GBM) effects on quantitative MRI of contralateral normal appearing white matter

PURPOSE

The objective was to investigate (with quantitative MRI) whether the normal appearing white matter (NAWM) of glioblastoma (GBM) patients on the contralateral side (cNAWM) was different from NAWM of healthy controls.

METHODS

Thirteen patients with newly diagnosed GBM and nine healthy age-matched controls were MRI-scanned with quantitative magnetization transfer (qMT), chemical exchange saturation transfer (CEST), and transverse relaxation time (T₂)-mapping. MRI scans were performed after surgery and before chemo-radiation treatment. Comprehensive qMT, CEST, T₂ data were acquired. A two-pool MT model was fit to qMT data in transient state, to calculate MT model parameters [Formula: see text]. CEST signal was isolated by removing the contributions from the MT and direct water saturation, and CEST signal was calculated for Amide (CEST_Amide), Amine (CEST_Amine) and nuclear overhauser effect, NOE (CEST_NOE).

RESULTS

There was no difference between GBM patients and normal controls in the qMT properties of the macromolecular pool [Formula: see text]. However, their free water pool spectrum was different (1/R_aT_2a,patient = 28.1 ± 3.9, 1/R_aT_2a,control = 25.0 ± 1.1, p = 0.03). This difference could be attributed to the difference in their T₂ time ([Formula: see text] = 83 ± 4, [Formula: see text] = 88 ± 1, p = 0.004). CEST signals were statistically significantly different with the CEST_Amide having the largest difference between the two cohorts (CEST_{Amide,patient} = 2.8 ± 0.4, CEST_{Amide,control} = 3.4 ± 0.5, p = 0.009).

CONCLUSIONS

CEST in cNAWM of GBM patients was lower than healthy controls which could be caused by modified brain metabolism due to tumor cell infiltration. There was no difference in MT properties of the patients and controls, however, the differences in free water pool properties were mainly due to reduced T₂ in cNAWM of the patients (resulting from structural changes and increased cellularity).

Quantitative Magnetization Transfer in Monitoring Glioblastoma (GBM) Response to Therapy

Quantitative magnetization transfer (qMT) was used as a biomarker to monitor glioblastoma (GBM) response to chemo-radiation and identify the earliest time-point qMT could differentiate progressors from non-progressors. Nineteen GBM patients were recruited and MRI-scanned before (Day0), two weeks (Day14), and four weeks (Day28) into the treatment, and one month after the end of the treatment (Day70). Comprehensive qMT data was acquired, and a two-pool MT model was fit to the data. Response was determined at 3-8 months following the end of chemo-radiation. The amount of magnetization transfer ([Formula: see text]) was significantly lower in GBM compared to normal appearing white matter (p < 0.001). Statistically significant difference was observed in [Formula: see text] at Day0 between non-progressors (1.06 ± 0.24) and progressors (1.64 ± 0.48), with p = 0.006. Changes in several qMT parameters between Day14 and Day0 were able to differentiate the two cohorts with [Formula: see text] providing the best separation (relative [Formula: see text] = 1.34 ± 0.21, relative [Formula: see text] = 1.07 ± 0.08, p = 0.031). Thus, qMT characteristics of GBM are more sensitive to treatment effects compared to clinically used metrics. qMT could assess tumor aggressiveness and identify early progressors even before the treatment. Changes in qMT parameters within the first 14 days of the treatment were capable of separating early progressors from non-progressors, making qMT a promising biomarker to guide adaptive radiotherapy for GBM.

SEOM clinical guidelines for diagnosis and treatment of glioblastoma (2017)

Glioblastoma (GB) is the most common brain malignancy and accounts for over 50% of all high-grade gliomas. Radiotherapy (RT) with concomitant and adjuvant temozolomide (TMZ) chemotherapy is the current standard of care for patients with newly diagnosed GB up to age 70. Recently, a new standard of care has been adopted for elderly patients (≥ 65 years) based on short course of RT and TMZ. Several clinically relevant molecular markers that assist in diagnosis and prognosis have recently been identified. The treatment for recurrent GB is not well defined, and decision-making is usually based on prior strategies as well as several clinical and radiological factors. The presence of neurologic deficits and seizures can significantly impact quality of life.

Complications of ventricular entry during craniotomy for brain tumor resection

OBJECTIVE Recent studies have demonstrated that periventricular tumor location is associated with poorer survival and that tumor location near the ventricle limits the extent of resection. This finding may relate to the perception that ventricular entry leads to further complications and thus surgeons may choose to perform less aggressive resection in these areas. However, there is little support for this view in the literature. This study seeks to determine whether ventricular entry is associated with more complications during craniotomy for brain tumor resection. METHODS A retrospective analysis of patients who underwent craniotomy for tumor resection at Henry Ford Hospital between January 2010 and November 2012 was conducted. A total of 183 cases were reviewed with attention to operative entry into the ventricular system, postoperative use of an external ventricular drain (EVD), subdural hematoma, hydrocephalus, and symptomatic intraventricular hemorrhage (IVH). RESULTS Patients in whom the ventricles were entered had significantly higher rates of any complication (46% vs 21%). Complications included development of subdural hygroma, subdural hematoma, intraventricular hemorrhage, subgaleal collection, wound infection, urinary tract infection/deep venous thrombosis, hydrocephalus, and ventriculoperitoneal (VP) shunt placement. Specifically, these patients had significantly higher rates of EVD placement (23% vs 1%, p < 0.001), hydrocephalus (6% vs 0%, p = 0.03), IVH (14% vs 0%, p < 0.001), infection (15% vs 5%, p = 0.04), and subgaleal collection (20% vs 4%, p < 0.001). It was also observed that VP shunt placement was only seen in cases of ventricular entry (11% vs 0%, p = 0.001) with 3 of 4 of these patients having a large ventricular entry (defined here as entry greater than a pinhole [< 3 mm] entry). Furthermore, in a subset of glioblastoma patients with and without ventricular entry, Kaplan-Meier estimates for survival demonstrated a median survival time of 329 days for ventricular entry compared with 522 days for patients with no ventricular entry (HR 1.13, 95% CI 0.65-1.96; p = 0.67). CONCLUSIONS There are more complications associated with ventricular entry during brain tumor resection than in nonviolated ventricular systems. Better strategies for management of periventricular tumor resection should be actively sought to improve resection and survival for these patients.

Intravoxel Incoherent Motion Metrics as Potential Biomarkers for Survival in Glioblastoma

Objective

Intravoxel incoherent motion (IVIM) is an MRI technique with potential applications in measuring brain tumor perfusion, but its clinical impact remains to be determined. We assessed the usefulness of IVIM-metrics in predicting survival in newly diagnosed glioblastoma.

Methods

Fifteen patients with glioblastoma underwent MRI including spin-echo echo-planar DWI using 13 b-values ranging from 0 to 1000 s/mm². Parametric maps for diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (f) were generated for contrast-enhancing regions (CER) and non-enhancing regions (NCER). Regions of interest were manually drawn in regions of maximum f and on the corresponding dynamic susceptibility contrast images. Prognostic factors were evaluated by Kaplan-Meier survival and Cox proportional hazards analyses.

Results

We found that f_CER and D*_CER correlated with rCBF_CER. The best cutoffs for 6-month survival were f_CER>9.86% and D*_CER>21.712 x10⁻³mm²/s (100% sensitivity, 71.4% specificity, 100% and 80% positive predictive values, and 80% and 100% negative predictive values; AUC:0.893 and 0.857, respectively). Treatment yielded the highest hazard ratio (5.484; 95% CI: 1.162–25.88; AUC: 0.723; P = 0.031); f_CER combined with treatment predicted survival with 100% accuracy.

Conclusions

The IVIM-metrics f_CER and D*_CER are promising biomarkers of 6-month survival in newly diagnosed glioblastoma.

Guidelines, "minimal requirements" and standard of care in glioblastoma around the Mediterranean Area: A report from the AROME (Association of Radiotherapy and Oncology of the Mediterranean arEa) Neuro-Oncology working party

Glioblastoma is the most common and the most lethal primary brain tumor in adults. Although studies are ongoing, the epidemiology of glioblastoma in North Africa (i.e. Morocco, Algeria and Tunisia) remains imperfectly settled and needs to be specified for a better optimization of the neuro-oncology healthcare across the Mediterranean area and in North Africa countries. Over the last years significant therapeutic advances have been accomplished improving survival and quality of life of glioblastoma patients. Indeed, concurrent temozolomide-radiotherapy (temoradiation) and adjuvant temozolomide has been established as the standard of care associated with a survival benefit and a better outcome. Therefore, considering this validated strategy and regarding the means and some other North Africa countries specificities, we decided, under the auspices of AROME (association of radiotherapy and oncology of the Mediterranean area; www.aromecancer.org), a non-profit organization, to organize a dedicated meeting to discuss the standards and elaborate a consensus on the "minimal requirements" adapted to the local resources. Thus, panels of physicians involved in daily multidisciplinary brain tumors management in the two borders of the Mediterranean area have been invited to the AROME neuro-oncology working party. We report here the consensus, established for minimal human and material resources for glioblastoma diagnosis and treatment faced to the standard of care, which should be reached. If the minimal requirements are not reached, the patients should be referred to the closest specialized medical center where at least minimal requirements, or, ideally, the standard of care should be guaranteed to the patients.

Molecular genetics of gliomas

Diffusely infiltrating gliomas are the most common primary brain tumors and include astrocytomas, oligodendrogliomas, and oligoastrocytomas of grades II and III and glioblastoma (GBM), grade IV. Histologic classification is increasingly aided by molecular genetic studies, which assist in the diagnosis and provide prognostic and predictive value. Mutations in IDH1 are frequent in grades II and III astrocytomas, oligodendrogliomas, and oligoastrocytomas, as well as secondary GBMs. IDH1-mutated diffuse gliomas are distinct from their IDH1 wild-type counterparts based on clinical features, growth rates, and concurrent genomic alterations. Grades II and III astrocytomas, as well as secondary GBMs are characterized by IDH1, TP53, and ATRX mutations, whereas oligodendrogliomas most frequently harbor codeletion of 1p/19q and mutations in CIC, FUBP1, and the TERT promoter. Primary GBMs frequently show molecular alterations in EGFR, PDGFRA, PTEN, TP53, NF1, and CDKN2A/B, as well as TERT promoter mutations, but not IDH mutations. Pediatric GBMs have a distinctive molecular pathogenesis, as H3F3A and DAXX mutations are frequent, and their gene expression profile is different than adult GBMs. Other lower-grade gliomas of childhood, such as pilocytic astrocytoma and pleomorphic xanthoastrocytoma, are characterized by BRAF mutations or activating gene rearrangements involving BRAF.

Molecular pathways in gliomagenesis and their relevance to neuropathologic diagnosis

Gliomas are a large and diverse group of primary brain tumors that include those that are diffusely infiltrative and others that are well-circumscribed and low grade. Diffuse gliomas are currently classified by the World Health Organization as astrocytomas, oligodendrogliomas, or oligoastrocytomas and range in grade from II to IV. Glioblastoma (GBM), World Health Organization grade IV, is the highest grade and most common form of astrocytoma. In the past, the diagnosis of gliomas was almost exclusively based on histopathologic features. More recently, improved understanding of molecular genetic underpinnings has led to ancillary molecular studies becoming standard for classification, prognostication, and predicting therapy response. Isocitrate dehydrogenase (IDH) mutations are frequent in grade II and III infiltrating gliomas and secondary GBMs. Infiltrating astrocytomas and secondary GBMs are characterized by IDH, TP53, and ATRX mutations, whereas oligodendrogliomas demonstrate 1p/19q codeletion and mutations in IDH, CIC, FUBP1, and the telomerase reverse transcriptase (TERT) promoter. Primary GBMs typically lack IDH mutations and are instead characterized by EGFR, PTEN, TP53, PDGFRA, NF1, and CDKN2A/B alterations and TERT promoter mutations. Pediatric GBMs differ from those in adults and frequently have mutations in H3F3A, ATRX, and DAXX, but not IDH. In contrast, circumscribed, low-grade gliomas of childhood, such as pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and ganglioglioma, often harbor mutations or activating gene rearrangements in BRAF. Neuropathologic assessment of gliomas increasingly relies on ancillary testing of molecular alterations for proper classification and patient management.

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.

The role of cytoreductive surgery in the management of progressive glioblastoma : a systematic review and evidence-based clinical practice guideline

QUESTION

Should patients with previously diagnosed malignant glioma who are suspected of experiencing progression of the neoplasm process undergo repeat open surgical resection?

TARGET POPULATION

These recommendations apply to adults with previously diagnosed malignant glioma who are suspected of experiencing progression of the neoplastic process and are amenable to surgical resection.

RECOMMENDATIONS LEVEL II

Repeat cytoreductive surgery is recommended in symptomatic patients with locally recurrent or progressive malignant glioma. The median survival in these patient diagnosed with glioblastoma is expected to range from 6 to 17 months following a second procedure. It is recommended that the following preoperative factors be considered when evaluating a patient for repeat operation: location of recurrence in eloquent/critical brain regions, Karnofsky Performance Status and tumor volume.

The role of neuropathology in the management of progressive glioblastoma : a systematic review and evidence-based clinical practice guideline

QUESTION

1. What are the most important diagnostic considerations in reporting progressive glioblastoma?

TARGET POPULATION

These recommendations apply to adults with progressive glioblastoma

RECOMMENDATIONS

LEVEL III

For patients who undergo biopsy or neurosurgical resection at the time of radiologic or clinical progression, it is recommended that the pathologist report the presence and extent of progressive neoplasm as well as the presence and extent of necrosis within the pathologic material examined. Furthermore, to ensure the proper interpretation of progressive glioblastoma, it is recommended that the pathologist take into account the patient's previous diagnosis and treatment, as well as the current clinical and neuroimaging features that have led to a second biopsy or resection.

QUESTION

2. What techniques and ancillary studies are most useful in separating malignant progression from treatment effect?

TARGET POPULATION

These recommendations apply to adults with progressive glioblastoma

RECOMMENDATIONS

LEVEL III

In the setting of prior radiation and chemotherapy, it is recommended to adhere to strict histologic criteria for microvascular proliferation and necrosis in order to establish a diagnosis of a glioblastoma. Immunohistochemistry and genetic studies are selectively recommended for distinguishing neoplastic cells from atypical reactive cells in progressive glioblastoma.

The role of imaging in the management of progressive glioblastoma : a systematic review and evidence-based clinical practice guideline

QUESTION

Which imaging techniques most accurately differentiate true tumor progression from pseudo-progression or treatment related changes in patients with previously diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adults with previously diagnosed glioblastoma who are suspected of experiencing progression of the neoplastic process.

RECOMMENDATIONS LEVEL II

Magnetic resonance imaging with and without gadolinium enhancement is recommended as the imaging surveillance method to detect the progression of previously diagnosed glioblastoma.

LEVEL II

Magnetic resonance spectroscopy is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma.

LEVEL III

The routine use of positron emission tomography to identify progression of glioblastoma is not recommended.

LEVEL III

Single-photon emission computed tomography imaging is recommended as a diagnostic method to differentiate true tumor progression from treatment-related imaging changes or pseudo-progression in patients with suspected progressive glioblastoma.

Operability of glioblastomas: "sins of action" versus "sins of non-action"

Despite prognosis of glioblastomas is still poor, mounting evidence suggests that more extensive surgical resections are associated with longer life expectancy. However, the surgical indications, at present, are far from uniform and the concept of operability is extremely surgeon-dependant. The results of glioblastoma resection in 104 patients operated on between March 2005 and April 2011 were reviewed with the aim to shed some light on the limits between 'sins of action' (operating upon complex tumors causing a permanent severe deficit) and 'sins of non-action' (considering inoperable tumors that can be resected with good results). Fifty-five patients (54.4 %) (Group 1) presented with a 'disputable' surgical indication because of one or more of the following clinico-radiological aspects: involvement of motor and language areas (39.4 %), deep location (7.7 %), corpus callosum infiltration (13.4 %), or major vessels encasement (8.6 %). Forty-six (42.5 %) patients (Group 2) presented with an 'indisputable' surgical indication (readily accessible tumors in non-eloquent areas). Overall mortality was 2.9 %. The mean overall survival was 19.8 months and not significantly different in the two Groups (20.4 Group 2 and 19.5 months for Group 1; p = 0.7). Patients with GTR and <72 years had a longer survival (p = 0.004 and 0.03, respectively). Seventy patients (69.3 %) showed an uneventful post-operative course, without statistical significance difference between Group 1 and 2. The gross total removal of glioblastoma with many complexities (Group 1) was found to be feasible with acceptable mortality, morbidity and long-term survival rates.

Toxicity and survival in primary glioblastoma patients treated with concomitant plus adjuvant temozolomide versus adjuvant temozolomide: results of a single-institution, retrospective, matched-pair analysis

BACKGROUND

To compare survival and hematological toxicity rates between two postoperative therapy regimens in patients with primary glioblastoma (GBM), namely temozolomide (TMZ) concomitant to radiation, followed by adjuvant TMZ, versus adjuvant TMZ after radiation only.

PATIENTS AND METHODS

A total of 191 patients with primary GBM were postoperatively treated with either radiation and concomitant TMZ, followed by adjuvant TMZ (Stupp protocol) (n = 154), or radiation followed by adjuvant TMZ (n = 37). The incidence of hematological adverse effects (AE) was recorded for all patients. From both treatment groups, 26 patients were matched according to age, Karnofsky performance scale (KPS) score, and O6-methylguanine-DNA-methyltransferase (MGMT) promoter methylation.

RESULTS

Hematological AEs were mild in both unmatched groups, but were significantly more frequent in the concomitant plus adjuvant TMZ group (p < 0.001). Matched-pair analysis confirmed significantly more frequent hematological AEs in the concomitant and adjuvant group compared to the sequential (adjuvant) TMZ group (p = 0,012). Patients treated with concomitant plus adjuvant TMZ showed significantly longer progression-free survival (PFS) (10.6 versus 6.6 months; p = 0.014), but no prolonged overall survival (OS) (16.9 vs. 15.6 months; p = 0.717) compared to patients who received the sequential treatment regimen.

CONCLUSION

In this retrospective study, the OS in patients with primary GBM treated with sequential TMZ following radiation appeared to be similar to that in patients treated with concomitant plus adjuvant TMZ. Given the significantly higher risk of hematological AE for concomitant treatment, the role of concomitant plus adjuvant TMZ use compared to sequential administration of TMZ, especially for patients with MGMT-unmethylated tumors, should be further evaluated.

Analysis of the growth dynamics of angiogenesis-dependent and -independent experimental glioblastomas by multimodal small-animal PET and MRI

The hypothesis of this study was that distinct experimental glioblastoma phenotypes resembling human disease can be noninvasively distinguished at various disease stages by imaging in vivo.

METHODS

Cultured spheroids from 2 human glioblastomas were implanted into the brains of nude rats. Glioblastoma growth dynamics were followed by PET using (18)F-FDG, (11)C-methyl-l-methionine ((11)C-MET), and 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) and by MRI at 3-6 wk after implantation. For image validation, parameters were coregistered with immunohistochemical analysis.

RESULTS

Two tumor phenotypes (angiogenic and infiltrative) were obtained. The angiogenic phenotype showed high uptake of (11)C-MET and (18)F-FLT and relatively low uptake of (18)F-FDG. (11)C-MET was an early indicator of vessel remodeling and tumor proliferation. (18)F-FLT uptake correlated to positive Ki67 staining at 6 wk. T1- and T2-weighted MR images displayed clear tumor delineation with strong gadolinium enhancement at 6 wk. The infiltrative phenotype did not accumulate (11)C-MET and (18)F-FLT and impaired the (18)F-FDG uptake. In contrast, the Ki67 index showed a high proliferation rate. The extent of the infiltrative tumors could be observed by MRI but with low contrast.

CONCLUSION

For angiogenic glioblastomas, noninvasive assessment of tumor activity corresponds well to immunohistochemical markers, and (11)C-MET was more sensitive than (18)F-FLT at detecting early tumor development. In contrast, infiltrative glioblastoma growth in the absence of blood-brain barrier breakdown is difficult to noninvasively follow by existing imaging techniques, and a negative (18)F-FLT PET result does not exclude the presence of proliferating glioma tissue. The angiogenic model may serve as an advanced system to study imaging-guided antiangiogenic and antiproliferative therapies.

Cost-effectiveness analysis of amino acid PET-guided surgery for supratentorial high-grade gliomas

High-grade gliomas are brain tumors associated with a devastating prognosis. Recent studies have indicated that the combined use of amino acid PET and MRI is superior to MRI alone to plan the surgical resection of high-grade gliomas. The aim of the study was to analyze the cost-effectiveness of the use of amino acid PET for the surgical resection of high-grade gliomas, compared with MRI alone, from the perspective of the national health insurance in Germany.

METHODS

A decision-tree model was set up to compare 2 strategies: the use of MRI alone and the combined use of MRI and PET for surgical resection of high-grade gliomas. For the analysis, 2 scenarios were calculated: a baseline scenario and a more expensive scenario, accounting for disease severity. To test the robustness of the results, probabilistic sensitivity analyses using Monte Carlo simulation were calculated.

RESULTS

Compared with MRI alone, the combined use of MRI and PET showed an incremental cost-effectiveness ratio of €2,948 (€1 ~ U.S.$1.3)per life-year gained for the baseline scenario and an incremental cost-effectiveness ratio of €4,105 per life-year gained for the admissible-charge-rate scenario. In the probabilistic sensitivity analysis in about 60% of the iterations, the combined use of PET and MRI was superior to MRI alone when assuming a willingness-to-pay threshold of €30,000.

CONCLUSION

The model indicates that the combined use of MRI and PET may be cost-effective. The results of this analysis have to be considered carefully because there was only limited empiric evidence for several input parameters.

Glioblastoma: clinical characteristics, prognostic factors and survival in 492 patients

OBJECTIVE

Glioblastoma is the most common and most malignant primary brain tumor in adults. The only overall accepted independent prognostic factors are patient age and performance. We present a large single institution patient series examined for prognostic factors using uni- and multivariate survival analysis.

METHODS

492 patients were included who underwent craniotomy for newly diagnosed glioblastoma WHO grade IV between 1990 and 2007 at our department. The association to patient survival was estimated using log-rank test for univariate analysis and cox regression method for multivariate analysis.

RESULTS

Median patient age was 62 years (mean: 60.4 years, range: 22-93 years), the male: female ratio was 1.26:1. Primary genesis was found in 91.0% of cases. A multifocal tumor was present in 110 cases (22.4%). The median pre- and post-operative Karnofsky Performance Score was 70. Total tumor resection was performed in 288 cases (58.5%), subtotal removal in 134 cases (27.2%). The following parameters were significantly associated with survival in univariate analysis: age, performance, primary genesis, multifocal tumor, neurological deficit, neuropsychological findings, seizures, incidental finding, total or subtotal resection, radiotherapy, chemotherapy, combined radio-/chemotherapy with temozolomide, re-craniotomy, second tumor in patient history. The following parameters were significantly associated with survival in multivariate analysis: age, performance, multifocal tumor, total or subtotal resection, radiotherapy, chemotherapy, combined radio-/chemotherapy with temozolomide.

CONCLUSION

In addition to patient age and performance, we identified multiple lesions and resection status as independent prognostic factors. Radiotherapy, chemotherapy and combined radio-/chemotherapy with temozolomide were significantly associated with prolonged survival.

Impact of 3,4-dihydroxy-6-18F-fluoro-L-phenylalanine PET/CT on managing patients with brain tumors: the referring physician's perspective

We investigated the impact of (18)F-DOPA brain PET/CT on the clinical management of patients with known or suspected brain tumors.

METHODS

A prospective survey of referring physicians was conducted. A pre-PET questionnaire inquired about indication, tumor histology or grade, level of suspicion for tumor recurrence, and planned management. Early post-PET questionnaires asked referring physicians to categorize PET findings as negative, equivocal, or positive; assessed the level of suspicion for primary or recurrent brain tumor; and recorded intended management changes prompted by PET findings. A late follow-up questionnaire 6 mo after the scan aimed at determining patient outcome (recurrence, survival). In addition, all referring physicians were contacted to determine whether management changes intended after (18)F-DOPA PET/CT were implemented.

RESULTS

Fifty-eight consecutive patients were included. The clinical suspicion for recurrence increased in 33%, remained unchanged in 50%, and decreased in 17% of patients after adding the PET/CT result to the available diagnostic data. The late post-PET questionnaire confirmed recurrence in 26 patients whereas 32 had stable disease or remained disease-free. (18)F-DOPA PET/CT resulted in intended management changes in 41% of patients. Changes in intended management from wait and watch to chemotherapy (6 patients [25%]) and from chemotherapy to wait and watch (4 patients [17%]) occurred most frequently. Clinical follow-up revealed that 75% of intended treatment changes were implemented.

CONCLUSION

(18)F-DOPA PET/CT changed the intended management of 41% of patients with brain tumors, and intended management changes were implemented in 75% of these. These changes suggest a potentially important clinical role of imaging amino acid transport in the management of brain tumor patients.

Patterns of care and survival for glioblastoma patients in the Veterans population

Survival outcomes and patterns of care for brain tumor patients in the USA Veterans population have not been previously published and the extent of variation in outcomes between Veterans and the rest of the USA is currently unknown. The Veterans healthcare administration (VA) provides comprehensive care to Veterans and their families and maintains the Veterans affairs central cancer registry (VACCR). This was a retrospective review of microscopically-confirmed, supratentorial glioblastoma multiforme in male Veterans actively followed by the VACCR; survival was analyzed and compared to a national cohort from the surveillance, epidemiology and end results program. We analyzed 1,219 Veterans with glioblastomas diagnosed between 1997 and 2006. Median survival was 6.5 months and 1, 2, and 5 years survival rates were 26.8, 5.4, and 0.5%, respectively. Patients receiving all three treatment modalities (surgical resection, radiotherapy, and chemotherapy) did best; these findings remained true among patients aged 70 and older such that these patients had an overall survival similar to those age <70. A comparable national cohort had longer median survival (9.0 months) and greater 1, 2, and 5 years survival rates (37.8, 12.8, and 4.1%) than the VA cohort. Survival and patterns of care are presented for the first time for Veterans with glioblastoma multiforme. In conclusion, we found that more aggressive therapy was associated with better survival, even among elderly Veterans and whether compared overall or by age group, VA patients showed decreased survival relative to a national cohort. We believe this potential disparity warrants further investigation.