Conventional MRI does not reliably distinguish radiation necrosis from tumor recurrence after stereotactic radiosurgery

Distinguishing radiation necrosis (RN) from tumor recurrence after stereotactic radiosurgery (SRS) for brain metastases is challenging. This study assesses the sensitivity (SN) and specificity (SP) of an MRI-based parameter, the "lesion quotient" (LQ), in characterizing tumor progression from RN. Records of patients treated with SRS for brain metastases between 01/01/1999 and 12/31/2009 and with histopathologic analysis of a subsequent contrast enhancing enlarging lesion at the treated site at a single institution were examined. The LQ, the ratio of maximal nodular cross sectional area on T2-weighted imaging to the corresponding maximal cross sectional area of T1-contrast enhancement, was calculated by a neuroradiologist blinded to the histopathological outcome. Cutoffs of <0.3, 0.3-0.6, and >0.6 have been previously suggested to have correlated with RN, mixed findings and tumor recurrence, respectively. These cutoff values were evaluated for SN, SP, positive predictive value (PPV) and negative predictive value (NPV). Logistic regression analysis evaluated for associated clinical factors. For the 51 patients evaluated, the SN, SP, PPV and NPV for identifying RN (LQ < 0.3) were 8, 91, 25 and 73 %, respectively. For the combination of recurrent tumor and RN (LQ 0.3-0.6) the SN, SP, PPV and NPV were 0, 64, 0 and 83 %. The SN, SP, PPV and NPV of the LQ for recurrent tumor (LQ > 0.6) were 59, 41, 62 and 39 %, respectively. Standard MRI techniques do not reliably discriminate between tumor progression and RN after treatment with SRS for brain metastases. Additional imaging modalities are warranted to aid in distinguishing between these diagnoses.

Ascending dose trials of the safety and tolerability of Toca 511, a retroviral replicating vector encoding cytosine deaminase, in patients with recurrent high-grade glioma

2101

Background: Patients with the most common and aggressive form of brain cancer, glioblastoma multiforme (GBM), have a poor prognosis and current treatments are only palliative. Gene therapy approaches using replication-deficient viral vectors have been investigated previously for GBM with limited efficacy, likely due to poor gene delivery throughout the tumor. Methods: Toca 511 is a novel retroviral replicating vector (RRV) that is engineered to deliver a modified cytosine deaminase prodrug activator gene (CD) selectively to cancer cells. In those cancer cells expressing the CD gene, the antifungal prodrug 5-FC is converted to 5-FU. We are currently evaluating the safety and tolerability of a single dose of Toca 511 administered by direct intratumoral injection to subjects with recurrent high grade glioma (rHGG). After a period of time during which the vector is allowed to spread through the tumor, the patient begins oral 5-FC which is repeated cyclically. Results: Three subjects have been enrolled in each of the first two dose groups. No dose limiting toxicities (DLTs) have been identified in these groups and the treatment was well tolerated. There have been no grade 3 or 4 AEs considered related to either Toca 511 or 5-FC. A further 9 subjects were then enrolled at the 3rd dose level and are being followed. A second study has been initiated in which Toca 511 is injected into the walls of the resection cavity at the time of surgery for rHGG and followed by cyclic treatment with oral 5-FC. Conclusions: These clinical studies are the first to investigate a RRV to deliver genes to human brain tumors and further dose escalation is anticipated.

Anaplastic oligodendroglial tumors: The Cleveland Clinic experience

2100

Background: Anaplastic oligodendroglial tumors include both anaplastic oligodendroglioma (AO), and anaplastic oligoastrocytoma (AOA), histological categories of WHO grade 3 gliomas. There is limited data on specific prognostic factors for patients with these tumors. Methods: After obtaining IRB approval, the Cleveland Clinic Brain Tumor and Neuro-Oncology Center’s database was used to identify patients with histologically confirmed AO and AOA at the time of diagnosis. Multivariable analysis was conducted with use of a Cox proportional hazards model and a stepwise selection algorithm that used p<0.05 both as the criteria for entry and retention in the model to identify independent predictors of survival. Results: Chart records of 139 patients, 52% of whom were male, diagnosed between 1992 and 2009 were included for analysis. Median age at presentation was 47 years (range, 18-83 years). 22% of patients had biopsy only, 35% had gross total resection, 43% had near total resection or subtotal resection. Following surgery, 30% of patients were treated with chemotherapy (CT) alone, 14% were treated with radiotherapy (RT) and 47% received both CT and RT. Median progression free survival and median overall survival (OS) were 29.0 and 58.7 months respectively. On multivariate analysis, four factors were identified as independent predictors of OS: age at diagnosis (≥50 vs. <50, p=0.004), Hypothyroidism (p=0.009), multifocal disease (p=0.005) and 1p 19q co-deletion (p<0.001). Choice of initial therapy did not impact survival in this cohort of patients. Conclusions: Older age, hypothyroidism and multifocal disease were associated with higher mortality. 1p, 19q co-deletion was associated with lower mortality. [Table: see text]

Adult low-grade gliomas: The Cleveland Clinic experience

2076

Background: Low-grade gliomas account for 10-20% of all primary brain tumors. There is limited data on specific prognostic factors for patients with low-grade gliomas. Methods: After obtaining IRB approval, the Cleveland Clinic Brain Tumor and Neuro-Oncology Center’s database was used to identify patients with histologically confirmed grade 2 glioma at the time of diagnosis. Multivariable analysis was conducted with use of a Cox proportional hazards model and a stepwise selection algorithm that used p<0.10 as the criteria for entry and p<0.05 as retention in the model to identify independent predictors of survival. Results: Chart records of 478 patients (54% of whom were men) diagnosed between 1991 and 2010 were included for analysis. The median age at presentation was 41 years (range, 18-83 years). 42% of patients had biopsy only, 27% had gross total resection, 6% had near total resection, and 25% had subtotal resection. 22% of patients were initially treated with radiation, 30% with adjuvant chemotherapy, and 7% with concurrent chemotherapy. Median progression free survival and median overall survival (OS) were 5.1 years and 12.8 years, respectively. On multivariate analysis, independent of additional therapy, five factors were identified as independent predictors of OS: age at diagnosis (p=0.002), Karnofsky performance status (KPS, p<0.0001), histology (astrocytoma vs. other, p=0.001), hemispheric location (left or bilateral involvement vs. right, p=0.02) and gender (male vs. female, p=0.0003). Conclusions: Older age, male gender, poor performance status, astrocytic histology, and left hemispheric or bilateral involvement are associated with higher mortality. [Table: see text]

Phase II trial of sunitinib as adjuvant therapy after stereotactic radiosurgery (SRS) in patients with 1-3 newly diagnosed brain metastases

2018

Background: For patients with 1-3 brain metastases, standard therapy after SRS is adjuvant whole brain radiotherapy (WBRT). SRS without WBRT carries a higher rate of brain relapse. Due to concerns about neurologic sequelae of WBRT, however, many patients and physicians opt to defer WBRT until the time of central nervous system (CNS) progression. This trial used sunitinib as an alternative to WBRT for post-SRS adjuvant therapy. Sunitinib inhibits vascular endothelial growth factor signaling, and we hypothesized that it would prevent growth of microscopic brain metastases presumed to be present. The objective was to use adjuvant sunitinib after SRS to prevent the emergence of new or progressive disease in the brain or at the site of SRS and to preserve neurocognitive function. Methods: Eligible patients had 1-3 newly diagnosed brain metastases, RTOG RPA class 1-2, and started sunitinib < 1 month after SRS and baseline neuropsychological testing (NPT). Patients with controlled systemic disease were allowed to continue chemotherapy for their primary disease according to a list of published regimens (therapy + sunitinib) included in the protocol. Patients received sunitinib 37.5 or 50 mg/d days 1-28 every 42 days until CNS progression. NPT and MRIs were obtained every 2 cycles. The primary endpoint was the rate of CNS progression at 6 months (PFS6) after SRS. Results: Fourteen patients enrolled. The median age was 59 (range 46-80). Main histologies: lung 36%, breast 21%, melanoma 14%. Toxicities: Grade 4: neutropenia [ANC] (1 pt); Grade 3: fatigue (5), ANC (2), rash (1). Dose reduction due to toxicity: 1 pt (to 37.5 mg/d). The CNS PFS6 and PFS12 were 50% + 13% and 43% + 13%, respectively. The median PFS was 6.6 months (95% C.I. 1.5-19). NPT results will be reported at the meeting. Conclusions: Sunitinib after SRS for 1-3 brain metastases was well tolerated with a PFS6 of 50%. The use of novel agents to prevent progressive brain metastasis after SRS requires the incorporation of chemotherapy regimens to control the patient’s primary disease. Future trials should continue to explore the paradigm of secondary chemoprevention of brain metastases after definitive local therapy (surgery or SRS).

A nomogram for individualized estimation of survival among patients with brain metastasis

PURPOSE

An estimated 24%-45% of patients with cancer develop brain metastases. Individualized estimation of survival for patients with brain metastasis could be useful for counseling patients on clinical outcomes and prognosis.

METHODS

De-identified data for 2367 patients with brain metastasis from 7 Radiation Therapy Oncology Group randomized trials were used to develop and internally validate a prognostic nomogram for estimation of survival among patients with brain metastasis. The prognostic accuracy for survival from 3 statistical approaches (Cox proportional hazards regression, recursive partitioning analysis [RPA], and random survival forests) was calculated using the concordance index. A nomogram for 12-month, 6-month, and median survival was generated using the most parsimonious model.

RESULTS

The majority of patients had lung cancer, controlled primary disease, no surgery, Karnofsky performance score (KPS) ≥ 70, and multiple brain metastases and were in RPA class II or had a Diagnosis-Specific Graded Prognostic Assessment (DS-GPA) score of 1.25-2.5. The overall median survival was 136 days (95% confidence interval, 126-144 days). We built the nomogram using the model that included primary site and histology, status of primary disease, metastatic spread, age, KPS, and number of brain lesions. The potential use of individualized survival estimation is demonstrated by showing the heterogeneous distribution of the individual 12-month survival in each RPA class or DS-GPA score group.

CONCLUSION

Our nomogram provides individualized estimates of survival, compared with current RPA and DS-GPA group estimates. This tool could be useful for counseling patients with respect to clinical outcomes and prognosis.

Recursive partitioning analysis of prognostic factors for glioblastoma patients aged 70 years or older

BACKGROUND

The most-used prognostic scheme for malignant gliomas included only patients aged 18 to 70 years. The purpose of this study was to develop a prognostic model for patients ≥70 years of age with newly diagnosed glioblastoma.

METHODS

A total of 437 patients ≥70 years of age with newly diagnosed glioblastoma, pooled from 2 tertiary academic institutions, was identified for recursive partitioning analysis (RPA). The resulting prognostic model, based on the final pruned RPA tree, was validated using 265 glioblastoma patients ≥70 years of age from a data set independently compiled by a French consortium.

RESULTS

RPA produced 9 terminal nodes, which were pruned to 4 prognostic subgroups with markedly different median survivals: subgroup I = patients <75.5 years of age who underwent surgical resection (9.3 months); subgroup II = patients ≥75.5 years of age who underwent surgical resection (6.4 months); subgroup III = patients with Karnofsky performance status of 70 to 100 who underwent biopsy only (4.6 months); and subgroup IV = patients with Karnofsky performance status <70 who underwent biopsy only (2.3 months). Application of this prognostic model to the French cohort also resulted in significantly different (P < .0001) median survivals for subgroups I (8.5 months), II (7.7 months), III (4.3 months), and IV (3.1 months).

CONCLUSIONS

This model divides elderly glioblastoma patients into prognostic subgroups that can be easily implemented in both the patient care and the clinical trial settings. This purely clinical prognostic model serves as a backbone for the future incorporation of the increasing number of potential molecular prognostic markers.

Convection-enhanced delivery of therapeutic agents into the brain

CED of therapeutic agents remains a promising strategy for treating malignant gliomas and non-neoplastic neurological diseases. Although initial clinical trials have failed to show survival benefit for new agents delivered via this approach, multiple earlier stage trials have addressed only a fraction of the myriad of technical and technological issues that surround this novel approach. Development of CED has been limited by the fact that both new technologies and novel therapeutic agents are being developed simultaneously.New trials are being planned to investigate agents that can be coinfused with radiographic tracers, as well as novel catheters that avoid problems with backflow and potentially will provide more reliable drug distribution.

Prospective Study of the Short-Term Adverse Effects of Gamma Knife Radiosurgery

Purpose of this study is to determine the types, incidence, and severity of acute complications of intracranial stereotactic radiosurgery (SRS), specifically Gamma Knife (GK). Patients who had never had previous SRS were eligible for this prospective IRB-approved study. The questionnaire used applicable questions from CTCAE v.3.0, the Brief Pain Questionnaire (Short Form), Brief Fatigue Inventory, and the Tinnitus Handicap Inventory. Questionnaires were obtained prior to Gamma Knife (GK), 1 week, 1 month, and 2 months to assess complications. Seventy-six eligible patients (median age of 62 years) had complete data and were analyzed. Diagnoses included: 26 (34%) with brain metastases, 15 (20%) with trigeminal neuralgia, 12 (16%) with schwannoma, 10 (13%) with meningioma, 7 (9%) with arteriovenous malformation, 3 (4%) with pituitary adenoma, and 3 (4%) with other. At 1 week, 24% developed minimal scalp numbness (p = 0.0004 baseline compared to 1 week). Only 13% had minimal scalp numbness at 1 month and 2% at 2 months (both p = NS compared to baseline). There was no difference in scalp tingling between baseline and the various time points. Thirteen percent developed pin site pain at 1 week with a median intensity level of 2 out of 10. By one month, only 3% had pin site pain with a median intensity level of 3 out of 10. Four percent developed pin-site infection at 1 week and none at 1 and 2 months. There was no significant difference in nausea from baseline at 1 week, but there was worsening nausea at 1 month (p = 0.0114). By 1 month, 10% reported new local hair loss. 23%, 16%, and 15% complained of new/worsening fatigue at 1 week, 1 month, and 2 months, respectively, but 40% reported fatigue at baseline. Balance improved following SRS over all time periods (for all comparisons, p < 0.009). 1%, 6%, and 3% developed new tinnitus at 1 week, 1 month, and 2 months, respectively, which was significant when comparing baseline to non-baseline (p = 0.0269). Thirty-two patients were employed prior to SRS. Three (9%) patients did not return to work. Twenty-seven (84%) patients returned to work a median of 4 days after SRS. Two people did not report their employment status after SRS. There was no significant difference in face swelling, headache, eye pain, vomiting, seizures, or passing out at any intervals compared to baseline. This prospective study demonstrates that GK is well tolerated with few patients developing major acute effects. Many patients are able to return to work shortly after GK.

Radiotherapeutic and surgical management for newly diagnosed brain metastasis(es): An American Society for Radiation Oncology evidence-based guideline

Purpose

To systematically review the evidence for the radiotherapeutic and surgical management of patients newly diagnosed with intraparenchymal brain metastases.

Methods and Materials

Key clinical questions to be addressed in this evidence-based Guideline were identified. Fully published randomized controlled trials dealing with the management of newly diagnosed intraparenchymal brain metastases were searched systematically and reviewed. The U.S. Preventative Services Task Force levels of evidence were used to classify various options of management.

Results

The choice of management in patients with newly diagnosed single or multiple brain metastases depends on estimated prognosis and the aims of treatment (survival, local treated lesion control, distant brain control, neurocognitive preservation).

Single brain metastasis and good prognosis (expected survival 3 months or more): For a single brain metastasis larger than 3 to 4 cm and amenable to safe complete resection, whole brain radiotherapy (WBRT) and surgery (level 1) should be considered. Another alternative is surgery and radiosurgery/radiation boost to the resection cavity (level 3). For single metastasis less than 3 to 4 cm, radiosurgery alone or WBRT and radiosurgery or WBRT and surgery (all based on level 1 evidence) should be considered. Another alternative is surgery and radiosurgery or radiation boost to the resection cavity (level 3). For single brain metastasis (less than 3 to 4 cm) that is not resectable or incompletely resected, WBRT and radiosurgery, or radiosurgery alone should be considered (level 1). For nonresectable single brain metastasis (larger than 3 to 4 cm), WBRT should be considered (level 3).

Multiple brain metastases and good prognosis (expected survival 3 months or more): For selected patients with multiple brain metastases (all less than 3 to 4 cm), radiosurgery alone, WBRT and radiosurgery, or WBRT alone should be considered, based on level 1 evidence. Safe resection of a brain metastasis or metastases causing significant mass effect and postoperative WBRT may also be considered (level 3).

Patients with poor prognosis (expected survival less than 3 months): Patients with either single or multiple brain metastases with poor prognosis should be considered for palliative care with or without WBRT (level 3).

It should be recognized, however, that there are limitations in the ability of physicians to accurately predict patient survival. Prognostic systems such as recursive partitioning analysis, and diagnosis-specific graded prognostic assessment may be helpful.

Conclusions

Radiotherapeutic intervention (WBRT or radiosurgery) is associated with improved brain control. In selected patients with single brain metastasis, radiosurgery or surgery has been found to improve survival and locally treated metastasis control (compared with WBRT alone).

Quality of life after gamma knife radiosurgery for benign lesions: a prospective study

This study was initiated to evaluate the impact of intracranial radiosurgery for non-malignant indications on a patient's quality of life (QOL).The study sample includes a total of 31 patients treated with single-fraction Gamma Knife radiosurgery (GKRS) for a non-malignant indication. Patients were treated at the Cleveland Clinic from 2005 through 2007 and all underwent pretreatment evaluation including screening for depression and anxiety, serum hemoglobin, hematocrit, calcium, albumin and thyroid stimulating hormone. Each patient was followed prospectively for eight weeks after treatment using a validated tool to assess fatigue and a separate questionnaire assessing quality of life. Dose and volume of GKRS were based on institutional practice and indication. The 13 question Functional Assessment of Chronic Illness Therapy Fatigue Scale (FACIT-F) was used to assess fatigue. Six additional questions assessing QOL outcomes not measured by the FACIT-F were added. Patients completed the questionnaire prior to GKRS and weekly for eight weeks. Questionnaires were scored using the FACIT scoring guidelines with a maximum score of 52. The additional questions were scored similarly with higher scores correlating with better QOL. The indications for treatment were arteriovenous malformation (5), schwannoma (12), trigeminal neuralgia (7), meningioma (4), pituitary adenoma (2), and glomus tumor (1). Median radiosurgery dose was 15 Gy (range 12-82 Gy). Doses for trigeminal neuralgia were prescribed to the 100% isodose line (IDL) while other lesions were treated to approximately the 50% IDL. Median volume of tissue treated was 2.5 cc (range 0.132-15.4 cc). Analysis of the 31 patients and 227 person-weeks of follow-up shows that GKRS does not adversely impact fatigue and QOL during the first 8 weeks after treatment. Mean FACIT-F score was 43 at baseline and 41, 43, 45, 43, 46, 44, 45, 47 at weeks 1-8 respectively after GKRS. In addition, questions assessing patients' quality of life, and ability to work and exercise showed no decline after GKRS. Mean baseline score for these questions was 13 and 18, 19, 19, 19, 20, 19, 19 and 21 at weeks 1-8 after GK. This analysis of a prospective data set indicates that Gamma Knife radiosurgery does not adversely impact levels of fatigue or quality of life during the first 8 weeks after treatment for benign indications.

Myeloid-derived suppressor cell accumulation and function in patients with newly diagnosed glioblastoma

To assess the accumulation of myeloid-derived suppressor cells (MDSCs) in the peripheral blood of patients with glioma and to define their heterogeneity and their immunosuppressive function. Peripheral blood mononuclear cells (PBMCs) from healthy control subjects and from patients with newly diagnosed glioma were stimulated with anti-CD3/anti-CD28 and T cells assessed for intracellular expression of interferon (IFN)-γ. Antibody staining of PBMCs from glioma patients and healthy donors (CD33, HLADR, CD15, and CD14) followed by 4-color flow cytometry analysis-defined MDSC levels in the peripheral blood. To assess the role of MDSCs in suppressing T cell IFNγ production, PBMCs were depleted of MDSCs using anti-CD33 and anti-CD15 antibody-coated beads prior to T cell stimulation. Enzyme-linked immunosorbent assays were used to assess plasma arginase activity and the level of granulocyte colony-stimulating factor (G-CSF). Patients with glioblastoma have increased MDSC counts (CD33+HLADR-) in their blood that are composed of neutrophilic (CD15(+); >60%), lineage-negative (CD15(-)CD14(-); 31%), and monocytic (CD14(+); 6%) subsets. After stimulation, T cells from patients with glioblastoma had suppressed IFN-γ production when compared with healthy, age-matched donor T cells. Removal of MDSCs from the PBMCs with anti-CD33/CD15-coated beads significantly restored T cell function. Significant increases in arginase activity and G-CSF levels were observed in plasma specimens obtained from patients with glioblastoma. The accumulation of MDSCs in peripheral blood in patients with glioma likely promotes T cell immune suppression that is observed in this patient population. Increased plasma levels of arginase and G-CSF may relate to MDSC suppressor function and MDSC expansion, respectively, in patients with glioma.

Impact of preexisting tumor necrosis on the efficacy of stereotactic radiosurgery in the treatment of brain metastases in women with breast cancer

BACKGROUND

Breast cancer is the second most common source of brain metastasis. Stereotactic radiosurgery (SRS) can be an effective treatment for some patients with brain metastasis (BM). Necrosis is a common feature of many brain tumors, including BM; however, the influence of tumor necrosis on treatment efficacy of SRS in women with breast cancer metastatic to the brain is unknown.

METHODS

A cohort of 147 women with breast cancer and BM treated consecutively with SRS over 10 years were studied. Of these, 80 (54.4%) had necrosis identified on pretreatment magnetic resonance images and 67 (46.4%) did not. Survival times were computed using the Kaplan-Meier method. Log-rank tests were used to compare groups with respect to survival times, Cox proportional hazards regression models were used to perform univariate and multivariate analyses, and chi-square and Fisher exact tests were used to compare clinicopathologic covariates.

RESULTS

Neurological survival (NS) and survival after SRS were decreased in BM patients with necrosis at the time of SRS compared with patients without necrosis by 32% and 27%, respectively (NS median survival, 25 vs 17 months [log-rank test, P = .006]; SRS median survival, 15 vs 11 months [log-rank test, P = .045]). On multivariate analysis, HER2 amplification status and necrosis influenced NS and SRS after adjusting for standard clinical features, including BM number, size, and volume as well as Karnofsky performance status.

CONCLUSION

Neuroimaging evidence of necrosis at the time of SRS significantly diminished the efficacy of therapy and was a potent prognostic marker.

p300- and Myc-mediated regulation of glioblastoma multiforme cell differentiation

Tumorigenic potential of glioblastoma multiforme (GBM) cells is, in part, attributable to their undifferentiated (neural stem cell-like) phenotype. Astrocytic differentiation of GBM cells is associated with transcriptional induction of Glial Fibrillary Acidic Protein (GFAP) and repression of Nestin, whereas the reciprocal transcription program operates in undifferentiated GBM cells. The molecular mechanisms underlying the regulation of these transcription programs remain elusive. Here, we show that the transcriptional co-activator p300 was expressed in GBM tumors and cell lines and acted as an activator of the GFAP gene and a repressor of the Nestin gene. On the other hand, Myc (formerly known as c-Myc overrode these p300 functions by repressing the GFAP gene and inducing the Nestin gene in GBM cells. Moreover, RNAi-mediated inhibition of p300 expression significantly enhanced the invasion potential of GBM cells in vitro. Taken together, these data suggest that dedifferentiated/undifferentiated GBM cells are more invasive than differentiated GBM cells. Because invasion is a major cause of GBM morbidity, differentiation therapy may improve the clinical outcome.

Silencing IL-13Rα2 promotes glioblastoma cell death via endogenous signaling

Glioblastoma multiforme (GBM) is one of the most lethal forms of cancer, with a survival rate of only 13% to 27% within 2 years of diagnosis despite optimal medical treatment. We hypothesize that the presence of a unique IL-13Rα2 decoy receptor prevents GBM apoptosis. This receptor has a high affinity for interleukin-13 (IL-13), binds the cytokine, and competitively inhibits the intracellular signaling cascade initiated by IL-13. In cells lacking the IL-13Rα2 decoy receptor, IL-13 initiates the production of 15-lipoxygenase-1 (15-LOX-1), which has been implicated in cellular apoptosis. Our group and others have shown that induction of 15-LOX-1 correlates with tumor cell death in colorectal, pancreatic, and prostate cancer. How 15-LOX-1 induces apoptosis remains unclear. Preliminary evidence in GBM cells implicates an apoptotic process mediated by PPARγ. 15-LOX-1 metabolites can modulate PPARγ and activation of PPARγ can suppress tumor growth. We hypothesize that in GBM, IL-13 can induce 15-LOX-1, which regulates cell apoptosis via signaling through PPARγ and that expression of IL-13Rα2 prevents apoptosis and contributes to tumor growth. Our in vitro and in vivo data support this. Knocking down IL-13Rα2 with short interfering RNA dramatically induces 15-LOX-1 expression, promotes apoptosis, and reduces GBM tumor growth in vivo. These findings identify a mechanism for eliminating the blockade of endogenous IL-13 signaling and for promotion of apoptosis, and characterize a role for 15-LOX-1 in GBM apoptosis. Identifying a mechanistic pathway that can be targeted for pharmacologic intervention will have applied implications to developing novel and effective treatments of GBM.

Application of Novel Response/Progression Measures for Surgically Delivered Therapies for Gliomas

BACKGROUND

The Response Assessment in Neuro-Oncology (RANO) Working Group is an international, multidisciplinary effort to develop new standardized response criteria for clinical trials in brain tumors. The RANO group identified knowledge gaps relating to the definitions of tumor response and progression after the use of surgical or surgically based treatments.

OBJECTIVE

To outline a proposal for new response and progression criteria for the assessment of the effects of surgery and surgically delivered therapies for patients with gliomas.

METHODS

The Surgery Working Group of RANO identified surgically related end-point evaluation problems that were not addressed in the original Macdonald criteria, performed an extensive literature review, and used a consensus-building process to develop recommendations for how to address these issues in the setting of clinical trials.

RESULTS

Recommendations were formulated for surgically related issues, including imaging changes associated with surgical resection or surgically mediated adjuvant local therapies, the determination of progression in the setting where all enhancing tumor has been removed, and how new enhancement should be interpreted in the setting where local therapies that are known to produce nonspecific enhancement have been used. Additionally, the terminology used to describe the completeness of surgical resections has been recognized to be inconsistently applied to enhancing vs nonenhancing tumors, and a new set of descriptors is proposed.

CONCLUSION

The RANO process is intended to produce end-point criteria for clinical trials that take into account the effects of prior and ongoing therapies. The RANO criteria will continue to evolve as new therapies and technologies are introduced into clinical trial and/or practice.

Treatment outcomes for patients with glioblastoma multiforme and a low Karnofsky Performance Scale score on presentation to a tertiary care institution. Clinical article

OBJECT

The object of this study was to determine the benefit of surgery, radiation, and chemotherapy for patients with glioblastoma multiforme (GBM) and a low Karnofsky Performance Scale (KPS) score.

METHODS

The authors retrospectively evaluated the records of patients who underwent primary treatment for pathologically confirmed GBM and with a KPS score ≤ 50 on initial evaluation for radiation therapy at a tertiary care institution between 1977 and 2006. Seventy-four patients with a median age of 69 years (range 19-88 years) and a median KPS score of 50 (range 20-50) were retrospectively grouped into the Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis (RPA) Classes IV (11 patients), V (15 patients), and VI (48 patients). Patients underwent biopsy (38 patients) or tumor resection (36 patients). Forty-seven patients received radiation. Nineteen patients also received chemotherapy (53% temozolomide), initiated concurrently (47%) or after radiotherapy.

RESULTS

The median survival overall was 2.3 months (range 0.2-48 months). Median survival stratified by RPA Classes IV, V, and VI was 6.6, 6.6, and 1.8 months, respectively (p < 0.001, log-rank test). Median survival for patients receiving radiation (5.2 months) was greater than that for patients who declined radiation (1.6 months, p < 0.001). Patients in RPA Class VI appeared to benefit from radiotherapy only when tumor resection was also performed. The median survival from treatment initiation was greater for patients receiving chemotherapy concomitantly with radiotherapy (9.8 months) as compared with radiotherapy alone (1.7 months, p = 0.002). Of 20 patients seen for follow-up in the clinic at a median of 48 days (range 24-196 days) following radiotherapy, 70% were noted to have an improvement in the KPS score of between 10 and 30 points from the baseline score. On multivariate analysis, only RPA class (p = 0.01), resection (HR = 0.37, p = 0.001), and radiation therapy (HR = 0.39, p = 0.02) were significant predictors of a decreased mortality rate.

CONCLUSIONS

Patients with a KPS score ≤ 50 appear to have increased survival and functional status following tumor resection and radiation. The extent of benefit from concomitant chemotherapy is unclear. Future studies may benefit from reporting that utilizes a prognostic classification system such as the RTOG RPA class, which has been shown to be effective at separating outcomes even in patients with low performance status. Patients with GBMs and low KPS scores need to be evaluated in prospective studies to identify the extent to which different therapies improve outcomes.

Gamma knife stereotactic radiosurgery for the management of incidentally-identified brain metastasis from non-small cell lung cancer

Initial staging workup of non-small cell lung cancer (NSCLC) patients has led to increased identification of incidental brain metastases in patients who otherwise have minimal or no neurologic symptoms. We present our experience treating these metastases with stereotactic radiosurgery (SRS) alone and compare outcomes to those of patients with brain metastases treated with other strategies. We queried our neuro-oncology and radiation oncology databases for patients with incidentally-identified NSCLC brain metastases treated with upfront SRS alone between 1997 and 2006. We performed a retrospective analysis to evaluate outcomes in these patients. We found 26 patients with incidentally-identified NSCLC brain metastases (KPS 90-100) treated with SRS alone within 60 days of diagnosis of the metastases. These patients underwent SRS at a median 15 days from diagnosis to an average of 1.6 lesions (range: 1-7), with a mean lesion volume of 1.86 cm(3). The median prescription was 24 Gy delivered to the median 53% isodose line. The median survival for these patients was 8.2 months (mean 12.3 months) from diagnosis of brain metastases. Local CNS progression occurred in 2 patients (7.7%, mean 229.7 days). Survival was not statistically different from similar patients treated with whole brain radiotherapy (WBRT) (P = 0.98), WBRT + Surgery (P = 0.07) or WBRT + SRS (P = 0.62). Patients with incidentally-identified NSCLC brain metastases treated with SRS alone may achieve a survival rate comparable to patients managed with other standard therapeutic modalities. Our findings suggest that SRS alone may be a viable therapeutic option for patients with incidentally-discovered NSCLC brain metastases.

Aggressive treatment is appropriate for glioblastoma multiforme patients 70 years old or older: a retrospective review of 206 cases

Elderly patients have largely been excluded from randomized trials for glioblastoma multiforme (GBM). We reviewed the results of treatment approaches, which included surgery, chemotherapy, and radiation in this group of patients. Patients were treated during the period 1979-2007 and were 70 years of age and older with histologically confirmed GBM. Overall survival (OS) was the primary endpoint of this retrospective study. Two hundred six patients 70 years of age and older were identified. Median age was 75 years (range 70-90). Median OS time was 4.5 months. Univariate analysis showed that OS was significantly impacted by KPS score (1.8 months for KPS ≤ 50 to 17.2 months for KPS ≥ 90, P < .001), age at diagnosis (5.1 months for age 70-79 versus 3.1 months for age ≥ 80, P < .001), and extent of disease (worse for bilateral disease [P = .003], multifocal disease [P = .005], and multicentric disease [P = .02]). On multivariate analysis, higher KPS score (P = .006), surgical resection (any surgery beyond biopsy) (P < .001), radiation therapy (P < .001), and chemotherapy (P < .001) were all found to be independently associated with improved OS. In this study of newly diagnosed glioblastoma patients over the age of 70 years, aggressive treatment with radiation, chemotherapy, and surgery is associated with OS.

Clinical trial end points for high-grade glioma: the evolving landscape

To review the strengths and weaknesses of primary and auxiliary end points for clinical trials among patients with high-grade glioma (HGG). Recent advances in outcome for patients with newly diagnosed and recurrent HGG, coupled with the development of multiple promising therapeutics with myriad antitumor actions, have led to significant growth in the number of clinical trials for patients with HGG. Appropriate clinical trial design and the incorporation of optimal end points are imperative to efficiently and effectively evaluate such agents and continue to advance outcome. Growing recognition of limitations weakening the reliability of traditional clinical trial primary end points has generated increasing uncertainty of how best to evaluate promising therapeutics for patients with HGG. The phenomena of pseudoprogression and pseudoresponse have made imaging-based end points, including overall radiographic response and progression-free survival, problematic. Although overall survival is considered the "gold-standard" end point, recently identified active salvage therapies such as bevacizumab may diminish the association between presalvage therapy and overall survival. Finally, advances in imaging as well as the assessment of patient function and well being have strengthened interest in auxiliary end points assessing these aspects of patient care and outcome. Better appreciation of the strengths and limitations of primary end points will lead to more effective clinical trial strategies. Technical advances in imaging as well as improved survival for patients with HGG support the further development of auxiliary end points evaluating novel imaging approaches as well as measures of patient function and well being.

Long-term outcomes of Gamma Knife radiosurgery in patients with vestibular schwannomas

Object

The authors sought to determine the long-term tumor control and side effects of Gamma Knife radiosurgery (GKRS) in patients with vestibular schwannomas (VS).

Methods

One hundred seventeen patients with VS underwent GKRS between January 1997 and February 2003. At the time of analysis, at least 5 years had passed since GKRS in all patients. The mean patient age was 60.9 years. The mean maximal tumor diameter was 1.77 ± 0.71 cm. The mean tumor volume was 1.95 ± 2.42 ml. Eighty-two percent of lesions received 1300 cGy and 14% received 1200 cGy. The median dose homogeneity ratio was 1.97 and the median dose conformality ratio was 1.78. Follow-up included MR imaging or CT scanning approximately every 6–12 months. Rates of progression to surgery were calculated using the Kaplan-Meier method.

Results

Of the 117 patients in whom data were analyzed, 103 had follow-up MR or CT images and 14 patients were lost to follow-up. Fifty-three percent of patients had stable tumors and 37.9% had a radiographically documented response. Imaging-documented tumor progression was present in 8 patients (7.8%), but in 3 of these the lesion eventually stabilized. Only 5 patients required a neurosurgical intervention. The estimated 1-, 3-, and 5-year rates of progression to surgery were 1, 4.6, and 8.9%, respectively. One patient (1%) developed trigeminal neuropathy, 4 patients (5%) developed permanent facial neuropathy, 3 patients (4%) reported vertigo, and 7 patients (18%) had new gait imbalance following GKRS.

Conclusions

Gamma Knife radiosurgery results in excellent local control rates with minimal toxicity for patients with VS. The authors recommend standardized follow-up to gain a better understanding of the long-term effects of GKRS.

Role of stereotactic radiosurgery for multiple (>4) brain metastases

Stereotactic radiosurgery (SRS) is a very important treatment option for patients with brain metastases. Prospective data supports the use of SRS for patients with 1-4 brain metastases. Although whole brain radiation therapy (WBRT) has been an effective adjunct to SRS and surgery and has also provided effective palliation for many patients with brain metastases, the potential side effects especially neurocognitive function decline has increased the use of SRS alone even for patients with multiple (>4) brain metastases despite data that suggests that tumor progression is worse than the potential neurocognitive effects of WBRT. In addition, current stereotactic radiosurgery machines and techniques allow the delivery of SRS to multiple lesions in an efficient manner. As a result, the optimal management of multiple brain metastases (>4) is becoming more contentious given the lack of prospective data. Until further data is available, a multidisciplinary team of neurosurgeons, radiation oncologists, medical oncologists and medical physicists should work closely together to implement individualized treatment for patients with multiple brain metastases. This paper will review some of the institutional, multi-institutional and randomized trials of SRS for patients with brain metastases, and review the outcomes for patients with multiple (>4) brain metastases treated by SRS and the associated costs.

Opportunities for clinical research in meningioma

Meningiomas, when benign, are commonly treated with surgical resection alone. However, the optimal treatment for patients with subtotally resected or recurrent World Health Organization (WHO) grade I tumors, or WHO grade II and III tumors, regardless of the extent of resection, is not well defined, with both a paucity of high quality published evidence as well as a perceived minimal clinical effect for currently available interventions, specifically in terms of prolonging survival. In consideration of the size of the patient population with incompletely treated or non-benign meningiomas, there are opportunities for conducting high quality, prospective, multicenter clinical trials. In this review, we discuss a number of trials that were attempted and/or completed by cooperative groups or clinical consortia, and describe areas of clearly unmet need in terms of defining the optimal treatment regimens. Finally, we discuss ongoing efforts to develop new trials to more definitively address important therapeutic questions.

Intracranial meningiomas of atypical (WHO grade II) histology

Atypical (WHO grade II) meningiomas occupy an intermediate risk group between benign (WHO grade I) and anaplastic (WHO grade III) meningiomas. Although grade II meningiomas have traditionally been recognized in only about 5% of cases, after changes in diagnostic criteria with the current 2007 WHO standards, they now comprise approximately 20-35% of all meningiomas. Given the magnitude of this change, much work is now needed to solidify the adoption of these standards, to render inter-observer and inter-institutional comparisons more uniform, and to more carefully define the incidence of grade II histology. However, it is clear that they carry a several-fold increased risk of recurrence, as well as an increased rate of mortality. We will discuss the definition, diagnosis, and treatment of patients with atypical meningioma; review the current phase II cooperative trials; and draw attention to some questions timely for pre-clinical and clinical research.

Poor drug distribution as a possible explanation for the results of the PRECISE trial

Object

Convection-enhanced delivery (CED) is a novel intracerebral drug delivery technique with considerable promise for delivering therapeutic agents throughout the CNS. Despite this promise, Phase III clinical trials employing CED have failed to meet clinical end points. Although this may be due to inactive agents or a failure to rigorously validate drug targets, the authors have previously demonstrated that catheter positioning plays a major role in drug distribution using this technique. The purpose of the present work was to retrospectively analyze the expected drug distribution based on catheter positioning data available from the CED arm of the PRECISE trial.

Methods

Data on catheter positioning from all patients randomized to the CED arm of the PRECISE trial were available for analyses. BrainLAB iPlan Flow software was used to estimate the expected drug distribution.

Results

Only 49.8% of catheters met all positioning criteria. Still, catheter positioning score (hazard ratio 0.93, p = 0.043) and the number of optimally positioned catheters (hazard ratio 0.72, p = 0.038) had a significant effect on progression-free survival. Estimated coverage of relevant target volumes was low, however, with only 20.1% of the 2-cm penumbra surrounding the resection cavity covered on average. Although tumor location and resection cavity volume had no effect on coverage volume, estimations of drug delivery to relevant target volumes did correlate well with catheter score (p < 0.003), and optimally positioned catheters had larger coverage volumes (p < 0.002). Only overall survival (p = 0.006) was higher for investigators considered experienced after adjusting for patient age and Karnofsky Performance Scale score.

Conclusions

The potential efficacy of drugs delivered by CED may be severely constrained by ineffective delivery in many patients. Routine use of software algorithms and alternative catheter designs and infusion parameters may improve the efficacy of drugs delivered by CED.

p300- and Myc-mediated regulation of glioblastoma multiforme cell differentiation

Tumorigenic potential of glioblastoma multiforme (GBM) cells is, in part, attributable to their undifferentiated (neural stem cell-like) phenotype. Astrocytic differentiation of GBM cells is associated with transcriptional induction of Glial Fibrillary Acidic Protein (GFAP) and repression of Nestin, whereas the reciprocal transcription program operates in undifferentiated GBM cells. The molecular mechanisms underlying the regulation of these transcription programs remain elusive. Here, we show that the transcriptional co-activator p300 was expressed in GBM tumors and cell lines and acted as an activator of the GFAP gene and a repressor of the Nestin gene. On the other hand, Myc (formerly known as c-Myc overrode these p300 functions by repressing the GFAP gene and inducing the Nestin gene in GBM cells. Moreover, RNAi-mediated inhibition of p300 expression significantly enhanced the invasion potential of GBM cells in vitro. Taken together, these data suggest that dedifferentiated/undifferentiated GBM cells are more invasive than differentiated GBM cells. Because invasion is a major cause of GBM morbidity, differentiation therapy may improve the clinical outcome.

Effect of alternative temozolomide schedules on glioblastoma O(6)-methylguanine-DNA methyltransferase activity and survival

Background:

O⁶-methylguanine-DNA methyltransferase (MGMT) expression in glioblastoma correlates with temozolomide resistance. Dose-intense temozolomide schedules deplete MGMT activity in peripheral blood mononuclear cells; however, no published data exist evaluating the effect of temozolomide schedules on intracranial tumour MGMT activity.

Methods:

Human glioblastoma cells (GBM43) with an unmethylated MGMT promoter were implanted intracranially in immunodeficient rodents. Three weeks later, animals received temozolomide 200 mg m⁻² for 5 days (schedule A, standard dose) or 100 mg m⁻² for 21 days (schedule B, dose intense).

Results:

Tumour MGMT activity was depleted by day 6 in both treatment groups compared with baseline. O⁶-methylguanine-DNA methyltransferase activity returned to baseline by day 22 in the schedule A group, but remained suppressed in the schedule B group. By day 29, MGMT activity had returned to baseline in both groups. Mean tumour volume was significantly decreased compared with untreated controls with either schedule (P<0.01), although neither schedule was superior (P=0.60). Median survival was 64, 42, and 28 days for schedule A, schedule B, and no drug, respectively (P<0.001 A or B vs control, P=NS A vs B).

Conclusions:

Dose-intense temozolomide prolongs tumour MGMT activity depletion compared with standard dosing, however, survival was not improved in this model.

IL-8 is a mediator of NF-κB induced invasion by gliomas

Glioblastoma (GBM) is the most common and deadly form of primary brain tumor with a median survival of eleven months, despite use of extensive chemotherapy, radiotherapy and surgery. We have previously shown that nuclear factor-kappa B (NF-κB) is aberrantly expressed in GBM tumors and primary cell lines derived from tumor tissue. Here we show that IL-8, a chemokine is also aberrantly expressed by GBM cell lines and expression of IL-8 is in large part, attributable to the aberrant activation of NF-κB. We hypothesized that invasiveness of GBM cells is driven at least in part by aberrantly expressed IL-8. In support of the hypothesis we found that treatment of glioma cells with an IL-8 neutralizing antibody markedly decreased their invasiveness compared to cells treated with control IgG or left untreated. Furthermore, downregulation of IL-8 protein production with use of IL-8 targeted siRNA also resulted in decreased invasion in matrigel. We next investigated the presence of IL-8 receptors by FACS analysis and found that GBM cells (U87, U251, D54 and LN229) only express CXCR1 but not CXCR2. Treatment of U87 cells with a blocking CXCR1 antibody reduced their invasion through matrigel. Finally, we found that addition of exogenous IL-8, following downregulation of NF-κB which results in loss of endogenous IL-8 production, incompletely restored tumor cell invasion. Our data indicate that IL-8 is necessary but not solely responsible for glioma cell invasion and mediates its effect in an autocrine manner.

Updated response assessment criteria for high-grade gliomas: response assessment in neuro-oncology working group

Currently, the most widely used criteria for assessing response to therapy in high-grade gliomas are based on two-dimensional tumor measurements on computed tomography (CT) or magnetic resonance imaging (MRI), in conjunction with clinical assessment and corticosteroid dose (the Macdonald Criteria). It is increasingly apparent that there are significant limitations to these criteria, which only address the contrast-enhancing component of the tumor. For example, chemoradiotherapy for newly diagnosed glioblastomas results in transient increase in tumor enhancement (pseudoprogression) in 20% to 30% of patients, which is difficult to differentiate from true tumor progression. Antiangiogenic agents produce high radiographic response rates, as defined by a rapid decrease in contrast enhancement on CT/MRI that occurs within days of initiation of treatment and that is partly a result of reduced vascular permeability to contrast agents rather than a true antitumor effect. In addition, a subset of patients treated with antiangiogenic agents develop tumor recurrence characterized by an increase in the nonenhancing component depicted on T2-weighted/fluid-attenuated inversion recovery sequences. The recognition that contrast enhancement is nonspecific and may not always be a true surrogate of tumor response and the need to account for the nonenhancing component of the tumor mandate that new criteria be developed and validated to permit accurate assessment of the efficacy of novel therapies. The Response Assessment in Neuro-Oncology Working Group is an international effort to develop new standardized response criteria for clinical trials in brain tumors. In this proposal, we present the recommendations for updated response criteria for high-grade gliomas.

PTPmu suppresses glioma cell migration and dispersal

The cell-surface receptor protein tyrosine phosphatase mu (PTPmu) is a homophilic cell adhesion molecule expressed in CNS neurons and glia. Glioblastomas (GBMs) are the highest grade of primary brain tumors with astrocytic similarity and are characterized by marked dispersal of tumor cells. PTPmu expression was examined in human GBM, low-grade astrocytoma, and normal brain tissue. These studies revealed a striking loss of PTPmu protein expression in highly dispersive GBMs compared to less dispersive low-grade astrocytomas and normal brain. We hypothesized that PTPmu contributes to contact inhibition of glial cell migration by transducing signals in response to cell adhesion. Therefore, loss of PTPmu may contribute to the extensive dispersal of GBMs. The migration of brain tumor cells was assessed in vitro using a scratch wound assay. Parental U-87 MG cells express PTPmu and exhibited limited migration. However, short-hairpin RNA (shRNA)-mediated knockdown of PTPmu induced a morphological change and increased migration. Next, a brain slice assay replicating the three-dimensional environment of the brain was used. To assess migration, labeled U-87 MG glioma cells were injected into adult rat brain slices, and their movement was followed over time. Parental U-87 MG cells demonstrated limited dispersal in this assay. However, PTPmu shRNA induced migration and dispersal of U-87 MG cells in the brain slice. Finally, in a mouse xenograft model of intracranially injected U-87 MG cells, PTPmu shRNA induced morphological heterogeneity in these xenografts. Together, these data suggest that loss of PTPmu in human GBMs contributes to tumor cell migration and dispersal, implicating loss of PTPmu in glioma progression.

Histidine-rich glycoprotein modulates the anti-angiogenic effects of vasculostatin

Brain angiogenesis inhibitor 1 (BAI1) is a transmembrane protein expressed on glial cells within the brain. Its expression is dramatically down-regulated in many glioblastomas, consistent with its functional ability to inhibit angiogenesis and tumor growth in vivo. We have shown that the soluble anti-angiogenic domain of BAI1 (termed Vstat120) requires CD36, a cell surface glycoprotein expressed on microvascular endothelial cells (MVECs), for it to elicit an anti-angiogenic response. We now report that Vstat120 binding to CD36 on MVECs activates a caspase-mediated pro-apoptotic pathway, and this effect is abrogated by histidine-rich glycoprotein (HRGP). HRGP is a circulating glycoprotein previously shown to function as a CD36 decoy to promote angiogenesis in the presence of thrombospondin-1 or -2. Data here show that Vstat120 specifically binds HRGP. Under favorable MVEC growth conditions this interaction allows chemotactic-directed migration as well as endothelial tube formation to persist in in vitro cellular systems, and increased tumor growth in vivo as demonstrated in both subcutaneous and orthotopic brain tumor models, concomitant with an increase in tumor vascularity. Finally, we show that HRGP expression is increased in human brain cancers, with the protein heavily localized to the basement membrane of the tumors. These data help define a novel angiogenic axis that could be exploited for the treatment of human cancers and other diseases where excess angiogenesis occurs.

Stereotactic radiosurgery for single brainstem metastases: the cleveland clinic experience

PURPOSE

To assess the imaging and clinical outcomes of patients with single brainstem metastases treated with stereotactic radiosurgery (SRS).

MATERIALS AND METHODS

We retrospectively reviewed the data from patients with single brainstem metastases treated with SRS. Locoregional control and survival were calculated using the Kaplan-Meier method. Prognostic factors were assessed using a Cox proportional hazards model.

RESULTS

Between 1997 and 2007, 43 patients with single brainstem metastases were treated with SRS. The median age at treatment was 59 years, the median Karnofsky performance status was 80, and the median follow-up was 5.3 months. The median dose was 15 Gy (range, 9.6-24), and the median conformality and heterogeneity index was 1.7 and 1.9, respectively. The median survival was 5.8 months from the procedure date. Of the 33 patient with post-treatment imaging available, a complete radiographic response was achieved in 2 (4.7%), a partial response in 8 (18.6%), and stable disease in 23 (53.5%). The 1-year actuarial rate of local control, distant brain control, and overall survival was 85%, 38.3%, and 31.5%, respectively. Of the 43 patients, 8 (19%) died within 2 months of undergoing SRS, and 15 (36%) died within 3 months. On multivariate analysis, greater performance status (hazard ratio [HR], 0.95, p = .004), score index for radiosurgery (HR, 0.7; p = .004), graded prognostic assessment score (HR, 0.48; p = .003), and smaller tumor volume (HR, 1.23, p = .002) were associated with improved survival. No Grade 3 or 4 toxicities were observed.

CONCLUSION

The results of our study have shown that SRS is a safe and effective local therapy for patients with brainstem metastases.

Future of convection-enhanced delivery in the treatment of brain tumors

Gliomas are one of the most lethal forms of cancer. The poor prognosis associated with these malignant primary brain tumors treated with surgery, radiotherapy and chemotherapy has led researchers to develop new strategies for cure. Interstitial drug delivery has been the most appealing method for the treatment of primary brain tumors because it provides the most direct method of overcoming the barriers to tumor drug delivery. By administering therapeutic agents directly to the brain interstitium and, more specifically, to tumor-infiltrated parenchyma, one can overcome the elevated interstitial pressure produced by brain tumors. Convection-enhanced delivery (CED) has emerged as a leading investigational delivery technique for the treatment of brain tumors. Clinical trials utilizing these methods have been completed, with mixed results, and several more are being initiated. However, the potential efficacy of these drugs may be limited by ineffective tissue distribution. The development of computer models/algorithms to predict drug distribution, new catheter designs, and utilization of tracer models and nanocarriers have all laid the groundwork for the advancement of CED. In this review, we summarize the recent past of the clinical trials utilizing CED and discuss emerging technologies that will shape future CED trials.

Phase II trial of erlotinib with temozolomide and radiation in patients with newly diagnosed glioblastoma multiforme

Approximately 40-50% of glioblastomas (GBM) overexpress epidermal growth factor receptor (EGFR). Erlotinib is a specific and potent EGFR tyrosine kinase inhibitor active against refractory GBM. Patients with non-small cell lung cancer and > or =grade 2 erlotinib-induced rash have improved survival. This phase 2 study assessed the efficacy and safety of concurrent radiation therapy (RT) and temozolomide with pharmacodynamic dose escalation of erlotinib in patients with newly diagnosed GBM. Patients received RT 60 Gy in 30 fractions with concurrent temozolomide 75 mg/m(2)/day x 42 days, followed in four weeks by temozolomide 150-200 mg/m(2)/day x 5, every 28 days for 12 cycles. Patients received erlotinib, 50 mg/day and increased by 50 mg/day every 2 weeks until the occurrence of grade 2 rash or to a maximum dose of 150 mg/day, from day 1 until disease progression. Twenty-seven patients were treated in this study. Twenty-two (81%) patients came off study for progressive disease (18 [67%]) or adverse events (4 [15%]). Eighteen patients (67%) have died. Median progression-free survival was 2.8 months, and the median overall survival was 8.6 months. Five patients remain on study with a median follow-up of 16 months. Grade 3/4 toxicities included thrombocytopenia, anemia, lymphopenia, fatigue, and febrile neutropenia. There were four deaths on study, three definitely treatment-related; therefore, the trial was terminated after accrual of 27 of 30 planned patients. Erlotinib co administered with RT and temozolomide was not efficacious and had an unacceptable toxicity.

Current concepts and newer developments in the treatment of malignant gliomas

Primary malignant brain tumors account for only 2% of all adult cancers but they cause a disproportionately high cancer-related disability and death. Survival of malignant glioma patients has changed only modestly over the past three decades despite the emergence of new treatment strategies for these tumors. In this review, we describe the standard treatment modalities for malignant glioma, which include surgery, radiation therapy and chemotherapy, as well as the status of novel therapies that have been developed to target various aspects of glioma cell biology. We also address this issue of drug delivery as a factor limiting the efficacy of systemic administration of therapeutics and attempts to overcome this barrier. Further progress towards a cure for malignant gliomas will require a greater understanding of the underlying mechanisms driving the growth, and resistance to therapy, of these challenging tumors.

Novel drug delivery strategies in neuro-oncology

Treatment of malignant gliomas represents one of the most formidable challenges in oncology. Despite treatment with surgery, radiation therapy, and chemotherapy, the prognosis remains poor, particularly for glioblastoma, which has a median survival of 12 to 15 months. An important impediment to finding effective treatments for malignant gliomas is the presence of the blood brain barrier, which serves to prevent delivery of potentially active therapeutic compounds. Multiple efforts are focused on developing strategies to effectively deliver active drugs to brain tumor cells. Blood brain barrier disruption and convection-enhanced delivery have emerged as leading investigational delivery techniques for the treatment of malignant brain tumors. Clinical trials using these methods have been completed, with mixed results, and several more are being initiated. In this review, we describe the clinically available methods used to circumvent the blood brain barrier and summarize the results to date of ongoing and completed clinical trials.

Novel drug delivery strategies in neuro-oncology

Treatment of malignant gliomas represents one of the most formidable challenges in oncology. Despite treatment with surgery, radiation therapy, and chemotherapy, the prognosis remains poor, particularly for glioblastoma, which has a median survival of 12 to 15 months. An important impediment to finding effective treatments for malignant gliomas is the presence of the blood brain barrier, which serves to prevent delivery of potentially active therapeutic compounds. Multiple efforts are focused on developing strategies to effectively deliver active drugs to brain tumor cells. Blood brain barrier disruption and convection-enhanced delivery have emerged as leading investigational delivery techniques for the treatment of malignant brain tumors. Clinical trials using these methods have been completed, with mixed results, and several more are being initiated. In this review, we describe the clinically available methods used to circumvent the blood brain barrier and summarize the results to date of ongoing and completed clinical trials.

End point assessment in gliomas: novel treatments limit usefulness of classical Macdonald's Criteria

Recent trials in glioma have revealed significant limitations in the end points used. This requires a critical and comprehensive review of how brain tumor trials are conducted, particularly of which end points are defined and how response and progression are defined.

Gender, race, and survival: a study in non-small-cell lung cancer brain metastases patients utilizing the radiation therapy oncology group recursive partitioning analysis classification

PURPOSE

To explore whether gender and race influence survival in non-small-cell lung cancer (NSCLC) in patients with brain metastases, using our large single-institution brain tumor database and the Radiation Therapy Oncology Group recursive partitioning analysis (RPA) brain metastases classification.

METHODS AND MATERIALS

A retrospective review of a single-institution brain metastasis database for the interval January 1982 to September 2004 yielded 835 NSCLC patients with brain metastases for analysis. Patient subsets based on combinations of gender, race, and RPA class were then analyzed for survival differences.

RESULTS

Median follow-up was 5.4 months (range, 0-122.9 months). There were 485 male patients (M) (58.4%) and 346 female patients (F) (41.6%). Of the 828 evaluable patients (99%), 143 (17%) were black/African American (B) and 685 (83%) were white/Caucasian (W). Median survival time (MST) from time of brain metastasis diagnosis for all patients was 5.8 months. Median survival time by gender (F vs. M) and race (W vs. B) was 6.3 months vs. 5.5 months (p = 0.013) and 6.0 months vs. 5.2 months (p = 0.08), respectively. For patients stratified by RPA class, gender, and race, MST significantly favored BFs over BMs in Class II: 11.2 months vs. 4.6 months (p = 0.021). On multivariable analysis, significant variables were gender (p = 0.041, relative risk [RR] 0.83) and RPA class (p < 0.0001, RR 0.28 for I vs. III; p < 0.0001, RR 0.51 for II vs. III) but not race.

CONCLUSIONS

Gender significantly influences NSCLC brain metastasis survival. Race trended to significance in overall survival but was not significant on multivariable analysis. Multivariable analysis identified gender and RPA classification as significant variables with respect to survival.

Salvage stereotactic radiosurgery effectively treats recurrences from whole-brain radiation therapy

BACKGROUND

The purpose of the current study was to examine overall survival (OS) and time to local failure (LF) in patients who received salvage stereotactic radiosurgery (SRS) for recurrent brain metastases (BM) after initial management that included whole-brain radiation therapy (WBRT).

METHODS

The records of 1789 BM patients from August 1989 to November 2004 were reviewed. Of these, 111 underwent WBRT as part of their initial management and SRS as salvage. Patients were stratified by Radiation Therapy Oncology Group (RTOG) recursive partitioning analysis class, primary disease, dimension of the largest metastases and number of BM at initial diagnosis, and time to first brain recurrence after WBRT. Overall survival, survival after SRS, and time to local and distant failure were analyzed.

RESULTS

The median OS from the initial diagnosis of BM was 17.7 months. Median survival after salvage SRS for the entire cohort was 9.9 months. Median survival after salvage SRS was 12.3 months in patients who had their first recurrence >6 months after WBRT versus 6.8 months for those who developed disease recurrence < or = 6 months after (P = .0061). Primary tumor site did not appear to affect survival after SRS. Twenty-eight patients (25%) developed local recurrence after their first SRS with a median time of 5.2 months. A dose <22 grays and lesion size >2 cm were found to be predictive of local failure.

CONCLUSIONS

In this study, patients who recurred after WBRT and were treated with salvage SRS were found to have good local control and survival after SRS. WBRT provided good initial control, as 45% of these patients failed >6 months after WBRT. Those with a longer time to failure after WBRT had significantly longer survival after SRS.