Creatine Chemical Exchange Saturation Transfer (Cr-CEST) Imaging Can Evaluate Cisplatin-induced Testicular Damage

PURPOSE

This study aimed to investigate the ability of creatine-chemical exchange saturation transfer (Cr-CEST) technique assessed through 7-T MRI to evaluate cisplatin-induced testicular damage.

METHODS

We used 8-10 weeks C57BL/6 mice (n = 10) that were divided into a control group (n = 5) and a cisplatin-treated group (n = 5). The cisplatin group received cisplatin at a dose of 15 mg/kg, via intraperitoneal injection, while the control group received saline. MR images of mouse testes were acquired under anesthesia 18 days after the injection using a horizontal 7-T scanner. The pulse sequence consisted of rapid acquisition with a relaxation enhancement (RARE) with magnetization transfer. The Z-spectra were collected using a 2000-ms saturation pulse at a B1 amplitude of 1.2 μT, with frequencies varying from -4.8 to +4.8 parts per million (ppm). Maps of magnetization transfer ratio with asymmetric analysis (MTRasym) were reconstructed at a Cr metabolite concentration of 1.8 ppm.

RESULTS

The Cr-CEST effect was significantly reduced in the cisplatin-treated group compared to the control group (MTRasym of control mice vs. cisplatin-treated mice: 6.9 [6-7.5] vs. 5.2 [4-5.5], P = 0.008). Correlation analysis revealed a strong correlation between the Cr-CEST effect and the pathological score (ρ = 0.93, P < 0.001).

CONCLUSION

Cr-CEST MRI can be useful for the evaluation of cisplatin-induced testicular damage in mice.

Quantitative Susceptibility Mapping and Amide Proton Transfer-Chemical Exchange Saturation Transfer for the Evaluation of Intracerebral Hemorrhage Model

This study aimed to evaluate an intracerebral hemorrhage (ICH) model using quantitative susceptibility mapping (QSM) and chemical exchange saturation transfer (CEST) with preclinical 7T-magnetic resonance imaging (MRI) and determine the potential of amide proton transfer-CEST (APT-CEST) for use as a biomarker for the early detection of ICH. Six Wistar male rats underwent MRI, and another six underwent histopathological examinations on postoperative days 0, 3, and 7. The ICH model was created by injecting bacterial collagenase into the right hemisphere of the brain. QSM and APT-CEST MRI were performed using horizontal 7T-MRI. Histological studies were performed to observe ICH and detect iron deposition at the ICH site. T2-weighted images (T2WI) revealed signal changes associated with hemoglobin degeneration in red blood cells, indicating acute-phase hemorrhage on day 0, late-subacute-phase hemorrhage on day 3, and chronic-phase hemorrhage on day 7. The susceptibility alterations in each phase were detected using QSM. QSM and Berlin blue staining revealed hemosiderin deposition in the chronic phase. APT-CEST revealed high magnetization transfer ratios in the acute phase. Abundant mobile proteins and peptides were observed in early ICH, which were subsequently diluted. APT-CEST imaging may be a reliable noninvasive biomarker for the early diagnosis of ICH.

Cellular Density in Adult Glioma, Estimated with MR Imaging Data and a Machine Learning Algorithm, Has Prognostic Power Approaching World Health Organization Histologic Grading in a Cohort of 1181 Patients

BACKGROUND AND PURPOSE

Recent advances in machine learning have enabled image-based prediction of local tissue pathology in gliomas, but the clinical usefulness of these predictions is unknown. We aimed to evaluate the prognostic ability of imaging-based estimates of cellular density for patients with gliomas, with comparison to the gold standard reference of World Health Organization grading.

MATERIALS AND METHODS

Data from 1181 (207 grade II, 246 grade III, 728 grade IV) previously untreated patients with gliomas from a single institution were analyzed. A pretrained random forest model estimated voxelwise tumor cellularity using MR imaging data. Maximum cellular density was correlated with the World Health Organization grade and actual survival, correcting for covariates of age and performance status.

RESULTS

A maximum estimated cellular density of >7681 nuclei/mm2 was associated with a worse prognosis and a univariate hazard ratio of 4.21 (P < .001); the multivariate hazard ratio after adjusting for covariates of age and performance status was 2.91 (P < .001). The concordance index between maximum cellular density (adjusted for covariates) and survival was 0.734. The hazard ratio for a high World Health Organization grade (IV) was 7.57 univariate (P < .001) and 5.25 multivariate (P < .001). The concordance index for World Health Organization grading (adjusted for covariates) was 0.761. The maximum cellular density was an independent predictor of overall survival, and a Cox model using World Health Organization grade, maximum cellular density, age, and Karnofsky performance status had a higher concordance (C = 0.764; range 0.748-0.781) than the component predictors.

CONCLUSIONS

Image-based estimation of glioma cellularity is a promising biomarker for predicting survival, approaching the prognostic power of World Health Organization grading, with added values of early availability, low risk, and low cost.

Metabolites Alterations and Liver Injury in Hepatic Encephalopathy Models Evaluated by Use of 7T-MRI

This study is to observe a thioacetamide (TAA) administered Hepatic encephalopathy (HE) model rats at three and ten days after TAA administration using liver MRI and brain MR Spectroscopy (MRS) by use of 7T-MRI. Forty-two Wistar rats (control group, n = 14) were intraperitoneally administered at 300 mg/kg (low-dose group, n = 14) or 400 mg/kg (high-dose group, n = 14) doses of TAA for induced of HE. At three days after TAA administration, glutamine (Gln) measured by MRS in high-dose and low-dose TAA groups showed significant increases in comparison to those of the control group (p < 0.05). Other metabolites measured by MRS showed no significant changes. Liver T1ρ and T2 relaxation times significantly increased three days after TAA injection compared to pre-injection. There was a correlation between Gln levels in the brain and the relaxation time of the liver. Furthermore, Gln levels and relaxation time changed depending on the TAA dose. The Gln concentration in the brain increased with the deterioration of liver function, as inferred from the prolonged relaxation time of the liver. The prolonged relaxation time of the liver corresponded with the level of Gln in the brain. Gln concentration for the alterations of brain metabolites and T1ρ relaxation time for the assessment of liver damage are useful markers for inter-organ association analysis in the HE model.

Evaluating the Cisplatin Dose Dependence of Testicular Dysfunction using Creatine Chemical Exchange Saturation Transfer Imaging

Chemical exchange saturation transfer (CEST) imaging is a non-invasive molecular imaging technique for indirectly measuring low-concentration endogenous metabolites. Conventional CEST has low specificity, owing to the effects of spillover, magnetization transfer (MT), and T1 relaxation, thus necessitating an inverse Z-spectrum analysis. We aimed to investigate the usefulness of inverse Z-spectrum analysis in creatine (Cr)-CEST in mice, by conducting preclinical 7T-magnetic resonance imaging (MRI) and comparing the conventional analysis metric magnetization transfer ratio (MTRconv) with the novel metric apparent exchange-dependent relaxation (AREX). We performed Cr-CEST imaging using 7T-MRI on mouse testes, using C57BL/6 mice as the control and a cisplatin-treated model. We prepared different doses of cisplatin to observe its dose dependence effect on testicular function. CEST imaging was obtained using an MT pulse with varying saturation frequencies, ranging from −4.8 ppm to +4.8 ppm. The application of control mouse testes improved the specificity of the CEST effect and image contrast between the testes and testicular epithelium. The cisplatin-treated model revealed impaired testicular function, and the Cr-CEST imaging displayed decreased Cr levels in the testes. There was a significant difference between the low- and high-dose models. The MTR values of Cr-CEST reflected the cisplatin dose dependence of testicular dysfunction.

Evaluation of liver T1rho and T2 values in acute liver inflammation models using 7T-MRI

PURPOSE

We measured the T 1rho and T 2 values the liver of acute liver inflammation model mice administered carbon tetrachloride (CCl 4) after 3 days and 6 days after dispensed, and we compared and examined whether each relaxation time can be used for detect acute liver inflammation.

METHODS

To create an acute liver inflammation model, a mixture of 0.2 ml / 100 g of CCl 4 with an equal amount of Sesame Oil was administered once intraperitoneally to C57BL / 6JJmsSlc mice (n = 15). On the 3 days and 6 days after administration, we acquired T 1rho mapping images and T 2 mapping images of the liver under respiratory synchronization using for preclinical 7T-MRI, and we measured T 1rho and T 2 values and compared statistically.

RESULTS

The liver T 1rho value of control mice was 33.9 ± 2.5 ms before CCl 4 administration, 43.2 ± 4.9 ms (p < 0.01) on the 3 days post CCl 4 injection, and 41.0 ± 1.2 ms (p < 0.001) on the 6 days post CCl 4 injection. The rate showed a significant increase of 27% on the 3 days after, as well as significant increase of 21% on the 6 days after. On the other hand, the liver T 2 value of control mice was 26.7 ± 1.9 ms before CCl 4 administration, 31.5 ± 3.4 ms (p < 0.05) 3 days post CCl 4 injection, and 29.0 ± 2.0 ms (p = 0.06) 6 days post CCl4 injection. The rate 3 days after CCl 4 administration showed a significant increase of 18%, after 6 days rate increased 9%, but no significant difference was confirmed compared with normal mice.

CONCLUSIONS

The T 1rho value changed significantly compared to the T 2 value, and a continuous change was observed even after 6 days. T 1rho mapping can diagnose acute liver inflammation.

[Longitudinal In Vivo Evaluation of Knee Osteoarthritis Model Using 7 T-MRI and Micro-CT]

PURPOSE

This study aims to investigate inflammatory changes and osteophyte formation in a rat osteoarthritis (OA) model longitudinally by using 7 T-magnetic resonance imaging (MRI) and micro-computed tomography (CT).

METHOD

This OA model is induced surgically by removing the medial collateral ligament and medial meniscus of the right knee joint. Using 7 T-MRI, we compared the relative signal value of the medial collateral site and the area (mm²) of the upper end of the tibia at the right knee joint to those of the left knee joint on T₂WI. In addition, we compared statistically the coefficient of variance (CV) of signal intensity on the subchondral bone, the area (mm²), the major axis (mm) and the minor axis (mm) of the upper end of the tibia by the use of micro-CT images.

RESULTS

In MRI experiment, the relative signal value was significantly higher at 2, 6, and 10 weeks postoperatively in the medial part of right knee joint than that in the left one. In micro-CT experiment, CV was significantly higher from 6 weeks postoperatively in the subchondral bone of surgical side. Rough and irregular surface at the medial tibia was also observed by 3D images.

CONCLUSION

Using 7 T-MRI and micro-CT, we're able to observe the knee osteoarthritis model rat longitudinally.

[In-vivo Evaluation of Bleomycin-induced Lung Fibrosis Model Mouse Using Ultra High-field 7 T-MRI and Micro-CT]

PURPOSE

This study aimed to perform longitudinal observation using 4D-computed tomography (CT) and compare images acquired by 3D-CT and 3D-ultrashort echo time (UTE) for evaluation of bleomycin-induced lung fibrosis model.

METHOD

The pulmonary fibrosis model was induced by instilling intratracheally with 50 μl of bleomycin. 4D-CT images were classified into four phases after acquisition and analyzed. To study the effects of respiratory gating, we aquired 3D-CT and 3D-UTE images with and without respiratory gating. For comparison between CT and UTE images, we performed no-triggerd 3D-CT and 3D-UTE under free-breathing. MR signal intensity ratio and CT values were measured in three regions of the upper, middle, and lower lung.

RESULTS

At 4DCT, total lung volume at maximum inspiration (4th phase) decreased significantly compared with control mouse and the ratio of lung volume at inspiration to expiration also showed a significant decrease. In comparison of the images between with and without respiratory gating, clearer images were obtained by respiratory gating. However, there was no significant difference between both. In comparison between CT and UTE images, magnetic resonance (MR) signal intensity ratio and CT value were significantly correlated, but 3D-UTE images showed poor delineation of the lower lung and that near the diaphragm compared with 3D-CT images.

CONCLUSION

4D micro-CT and nontriggered 3D UTE-magnetic resonance imaging (MRI) under free breathing can be useful to evaluate bleomycininduced lung fibrosis model mouse.

Abstract P6-03-04: Central nervous system miliary metastasis in breast cancer patients

Background: Little is known regarding central nervous system (CNS) miliary metastasis (MiM), which was first described as “carcinomatous encephalitis” by Madow and Alpers in 1951. The majority of reported cases arise from primary lung and gastrointestinal adenocarcinomas, with occasional melanoma primaries and one reported case in breast cancer. Moreover, clinicopathologic correlates, disease outcomes and prognostic factors in these patients are poorly understood. Although identified most frequently on neuroimaging, radiographic criteria to objectively diagnose MiM do not exist. In this analysis of patients with brain metastasis from primary breast cancer, we propose objective, stringent radiographic criteria for CNS MiM diagnosis and identify clinicopathologic factors contributing to disease outcomes.

Methods: Using a prospectively maintained electronic database, 1,002 female patients diagnosed with brain metastasis from primary breast cancer between 2000 and 2015 were identified. Only patients with neuroimaging available for direct review (CT or MRI) were included. Our radiographic criteria for MiM diagnosis were: 1) ≥20 metastatic lesions per image slice on ≥2 noncontiguous image slices by MRI, or 2) ≥10 lesions per image slice on ≥2 noncontiguous image slices by CT, and 3) MiM lesions were required to be present bilaterally and in both the supra- and infratentorial compartments. These criteria were established upon direct review of all neuroimaging by a neuroradiologist. Number and anatomic distribution of metastatic lesions were the patterns best observed to identify cases of CNS MiM on case review; lesion size was not a reliable pattern for MiM identification. Log rank tests were used for statistical analyses.

Results: Using stringent criteria, 486 patients were included in this analysis. Twenty patients with MiM were identified (4.1%). Ten patients were diagnosed with MiM at initial brain metastasis presentation; 10 developed MiM after known brain metastasis. Biomarker based subtype distribution was as follows: HR-/HER2- (TNBC) (n=8), HR+/HER2+ (n=3), HR+/HER2- (n=4), HR-/HER2+ (n=4), unknown (n=1).

Table 1: Disease Outcomes Based on Biomarker SubtypeBiomarker SubtypeMedian Time to MiM (months) (p=0.104)Median Survival after MiM (months) (p=0.008)TNBC (n=8)32.3 (12.1-132.5)1.8 (0.5-4.0)HR+/HER2+ (n=3)44.2 (33.2-71.5)10.8 (10.2-13.3)HR+/HER2- (n=4)110.2 (23.0-156.0)4.8 (0.8-9.8)HR-/HER2+ (n=4)27.1 (3.7-39.4)4.0 (1.8-5.0)All* (n=20)37.4 (3.7-156.0)3.7 (0.4-12.3)Key: BM: Brain metastasis; * Includes 1 patient with unknown subtype.

Conclusions: Reports of MiM consist overwhelmingly of lung and gastrointestinal adenocarcinoma primaries. This retrospective, observational study is the first to establish that CNS MiM occurs in breast cancer with an incidence of roughly 4%. Review of an additional 1,600 patient charts is underway, but this preliminary study is the first to identify clinicopathologic correlates and determine disease outcomes in patients with MiM; it is also the first to propose stringent radiographic criteria for the diagnosis of CNS MiM, and further updated data will be presented at the meeting.

Citation Format: Bashour SI, Ibrahim NK, Schomer DF, Colen RR, Sawaya R, Suki D, Rao G, Murthy RK, Moulder SL, Abugabal Y, Hess KR, Fuller GN. Central nervous system miliary metastasis in breast cancer patients [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-03-04.

Acute neurological visual loss in young adults: causes, diagnosis and management

Visual loss in the young adult can be caused by demyelinating diseases, inflammatory and autoimmune processes, infections, ischaemic events, and compressive lesions of the optic nerve. Diagnosis of the aetiologies of visual loss is reached by combining data from radiological studies, electrophysiological tests, and blood and cerebrospinal fluid analysis. Treatment is primarily aimed at decreasing the insult on the optic nerve and eventually controlling the primary disorder. The literature discusses separately the different aetiologies of visual loss. We present a review of the clinical characteristics of visual loss in the young adult, the different diagnostic measures, and the latest therapeutic strategies. The aim of this work is to summarise this entity in a practical way to guide clinicians in the diagnosis and management of this disorder.

PRODIGE: a randomized placebo-controlled trial of dalteparin low-molecular-weight heparin thromboprophylaxis in patients with newly diagnosed malignant glioma

BACKGROUND AND OBJECTIVES

Venous thromboembolism (VTE) occurs in 20-30% of patients with malignant glioma per year of survival. We tested the efficacy of long-term dalteparin low-molecular-weight heparin (LMWH) for prevention of VTE in these patients.

PATIENTS/METHODS

Adults with newly diagnosed malignant glioma were randomized to receive dalteparin 5000 anti-Xa units or placebo, both subcutaneously once daily for 6 months starting within 4 weeks of surgery. Treatment continued for up to 12 months. The primary outcome was the cumulative risk of VTE over 6 months. The target sample size was 512 patients. Events were adjudicated by a committee unaware of treatment.

RESULTS

The trial began in 2002 and closed in May 2006 because of expiration of study medication. Ninety-nine patients were randomized to LMWH and 87 to placebo. Twenty-two patients developed VTE in the first 6 months: nine in the LMWH group and 13 in the placebo group [hazard ratio (HR) = 0.51, 95% confidence interval (CI): 0.19-1.4, P = 0.29]. At 6 months, there were three major bleeds on LMWH and none on placebo; at 12 months, 5 (5.1%) major bleeds on LMWH and 1 (1.2%) on placebo occurred (HR = 4.2, 95% CI: 0.48-36, P = 0.22). All major bleeds were intracranial and occurred while on study medication. The 12-month mortality rates were 47.8% for LMWH and 45.4% for placebo (HR = 1.2, 95% CI: 0.73-2.0, P = 0.48).

CONCLUSIONS

Trends suggesting reduced VTE and increased intracranial bleeding were seen in the LMWH thromboprophylaxis group. The role of long-term anticoagulant thromboprophylaxis in patients with brain tumors remains uncertain.

Autophagy-inducing agents augment the antitumor effect of telerase-selve oncolytic adenovirus OBP-405 on glioblastoma cells

Oncolytic adenoviruses are a promising tool in cancer therapy. In this study, we characterized the role of autophagy in oncolytic adenovirus-induced therapeutic effects. OBP-405, an oncolytic adenovirus regulated by the human telomerase reverse transcriptase promoter (hTERT-Ad, OBP-301) with a tropism modification (RGD) exhibited a strong antitumor effect on glioblastoma cells. When autophagy was inhibited pharmacologically, the cytotoxicity of OBP-405 was attenuated. In addition, autophagy-deficient Atg5(-/-) mouse embryonic fibroblasts (MEFs) were less sensitive than wild-type MEFs to OBP-405. These findings indicate that OBP-405-induced autophagy is a cell killing effect. Moreover, autophagy-inducing therapies (temozolomide and rapamycin) synergistically sensitized tumor cells to OBP-405 by stimulating the autophagic pathway without altering OBP-405 replication. Mice harboring intracranial tumors treated with OBP-405 and temozolomide survived significantly longer than those treated with temozolomide alone, and mice treated with OBP-405 and the rapamycin analog RAD001 survived significantly longer than those treated with RAD001 alone. The observation that autophagy inducers increase OBP-405 antitumor activity suggests a novel strategy for treating patients with glioblastoma.

The impact of intra-operative high field magnetic resonance imaging on clinical decision making during oncologic neurosurgical procedures

19599

Background: Existing image guided surgical (IGS) technology used during resection of brain tumors is based on preoperative imaging modalities and are limited by their inability to demonstrate extent of resection (EOR) and compensate for anatomical changes which occur as a result of surgical manipulation (e.g. brain shift, tumor resection, spinal fluid loss). Having the ability to perform MRI during brain tumor surgery obviates many of these limitations. The purpose of this study was to determine the impact of intra-operative imaging with a high field MRI on brain tumor resection. Methods: Since September 2006, a total of 23 patients with brain tumors underwent resection at The University of Texas M. D. Anderson Cancer Center with intra-operative MR guidance (BrainLAB IGS system integrated with a 1.5T Siemens Espree scanner). For each patient, appropriate imaging was performed prior to craniotomy. Resection was then performed using image guidance. Surgeons completed a questionnaire documenting the reason for the scan and provided an estimation of EOR prior to and after the intraoperative scan. Multiple intraoperative scans were performed at the discretion of the operating surgeon. Results: In 23 patients, 25 scans were performed. The patients had a diagnosis of glioma (21), lymphoma (1), and schwannoma (1). Reasons for performing a scan included: evaluate EOR in 23 (92%) or update the IGS system in 2 (8%). Surgeons indicated in 21/23 (91%) scans performed to evaluate the extent of resection that they would have terminated the surgery prior to the scan. In 9/21 cases (43%), further surgery was performed after the scan to maximize EOR. In 10/24 (42%) cases, the pre-scan estimate of residual tumor matched the post-scan amount. The amount of residual tumor was correctly assessed (within 10%) prior to review of the MRI in 19/24 cases. The correlation between the pre-scan estimation of residual tumor and actual post-scan tumor was high (correlation coefficient 0.81, p<0.05). Conclusions: High field intra- operative MRI with high spatial resolution is a useful adjunct to a neurosurgical oncology practice and alters surgical decision making in a significant number of cases.

[Table: see text]

PRODIGE: A phase III randomized placebo-controlled trial of thromboprophylaxis using dalteparin low molecular weight heparin (LMWH) in patients with newly diagnosed malignant glioma

2011

Background: Venous thromboembolism (VTE) occurs in 20–30% of patients with malignant glioma per year of survival. We have conducted an RCT testing the efficacy and safety of long-term dalteparin for the prevention of VTE in newly diagnosed malignant glioma. Methods: Adults with newly diagnosed malignant glioma were randomized to receive dalteparin 5,000 anti-Xa units or placebo, both subcutaneously daily for 6 months starting within the first month after surgery. Patients were allowed to continue study medication for up to 12 months. Because of the poor prognosis of malignant glioma it was determined apriori that the primary outcome was 6-month VTE-free survival. In order to detect a 60% VTE hazard reduction with LMWH with 80% power, 512 patients were required. Results: Recruitment began October 2002 and was closed in May 2006 because of expiration of study medication and no further re-supply. Of the 563 patients screened at 15 centers, 174 were excluded. Of the 389 eligible patients approached for consent, 186 were randomized: 99 to LMWH, 87 to placebo. Twenty-one patients developed objectively confirmed VTE during the first 6 months: 9 on LMWH and 12 on placebo (11% and 17% respectively; HR=0.7, 95% CI: 0.37–1.5, p=0.3). Over the 12 months there were 5 (5.1%) major bleeds with LMWH and 1 (1.2%) with placebo (HR=4.0, 95%CI: 0.5–34, p=0.2). All major bleeds were intracranial. Twelve-month mortality was 48% for LMWH and 45% for placebo (HR=1.2, 95%CI: 0.7–1.9, p=0.5). Conclusions: Although there was a trend in favor of the LMWH reducing VTE this was not statistically significant, likely as a result of low power. There was also a trend for increased intracranial bleeding with LMWH. Our study confirms the high incidence of thromboembolism in these patients; however, the role of long-term anticoagulant thromboprophylaxis remains unclear. Supported in part by a grant in aid from Pfizer Inc. and the Ontario Cancer Research Network. The PRODIGE steering committee thanks Terri Finch for superb administrative support.

Pfizer

Temozolomide as a vaccine adjuvant in GBM

2020

Background: Cytotoxic chemotherapy that induces lymphopenia is predicted to ablate the benefits of active antitumor immunization. Temozolomide (TMZ) is an effective chemotherapeutic for patients with glioblastoma multiforme (GBM), but it induces significant lymphopenia. Methods: In a Phase II trial, patients with newly-diagnosed, completely resected GBM are vaccinated with an EGFRvIII-specific peptide q2 weeks X 3 after radiation (XRT)(∼60Gy) and TMZ (75mg/m2/d) and then monthly with 5 day TMZ cycles (200mg/m2/d). Results: TMZ induces transient, Grade 3 lymphopenia (< 500 cells/uL) in 70% of patients after the first TMZ cycle with nadirs occurring 14–21 days after treatment (n=10). Regulatory T cell (TReg) (CD4+CD25++CD45RO+FOXP3+) levels increased from 5.2+1.5% (3.3 - 7.5) to 11.8+2.6% (6.9 - 13.8)(P=0.0004; paired t-test) with TMZ and XRT and averaged 12.2+4.0% (6.4 - 18.1) after the second TMZ cycle (P=0.007) (n=6). Despite these findings, in patients assayed, both humoral and cellular EGFRvIII-specific immune responses appear to be enhanced with TMZ. Median survival and TTP after vaccination is 26.2 weeks with no patients progressing (n=8). Conclusions: Despite conventional dogma, we demonstrated that both chemotherapy and immunotherapy can be delivered concurrently without negating the effects of immunotherapy. TMZ-induced lymphopenia may prove to be synergistic with a peptide vaccine.

No significant financial relationships to disclose.

Aberrant FoxM1B expression increases matrix metalloproteinase-2 transcription and enhances the invasion of glioma cells

We recently showed that FoxM1 is overexpressed in human glioblastomas and that forced FoxM1B expression in anaplastic astrocytoma cells leads to the formation of highly invasive glioblastoma multiforme (GBM) in nude mice. However, the molecular mechanisms by which FoxM1 enhances glioma invasion are unknown. In this study, we found that FoxM1 overexpression increased matrix metalloproteinase (MMP)-2 expression in glioma cells, whereas blockade of FoxM1 expression suppressed MMP-2 expression. Transfection of FoxM1 into glioma cells directly activated the MMP-2 promoter, whereas inhibition of FoxM1 expression by FoxM1-siRNA suppressed its activation. We identified a FoxM1-binding site in the MMP-2 promoter and demonstrated that FoxM1 protein bound directly to it. Mutation of this FoxM1-binding site significantly attenuated MMP-2 promoter activity. Furthermore, FoxM1 overexpression increased the invasiveness of glioma cells, whereas inhibition of FoxM1 expression suppressed the invasiveness of GBM cells. Inhibition of MMP-2 by a specific MMP-2 inhibitor reversed the invasive phenotype of glioma cells overexpressing FoxM1. Finally, immunohistochemical analysis of 45 human GBM specimens showed a significant correlation between FoxM1 overexpression and elevated MMP-2 expression. Collectively, these findings provide evidence that FoxM1 contributes to glioma progression by enhancing MMP-2 gene transcription and thus tumor-cell invasion.

Two randomized vitamin D trials in ambulatory patients on anticonvulsants: Impact on bone

OBJECTIVE

To investigate the effects of two doses of vitamin D given over 1 year on bone density in ambulatory patients on long-term antiepileptic drug (AED) therapy.

METHODS

We conducted two parallel, randomized, controlled trials in 72 adults (18 to 54 years old) and 78 children and adolescents (10 to 18 years) on long-term AED therapy. They received either low-dose vitamin D 400 IU/day or high-dose vitamin D 4,000 IU/day (adults) and 2,000 IU/day (children/adolescents). Bone mineral density (BMD) was measured using dual-energy x-ray absorptiometry.

RESULTS

In adults, baseline BMD was lower than that of age- and gender-matched controls vs either a Western or an ethnically identical population. After 1 year, there were significant increases in BMD at all skeletal sites compared to baseline in the high-, but not in the low-dose treatment group. However, BMD at 1 year remained below normal. In children, baseline BMD was normal vs age- and gender-matched controls and showed significant and comparable increases in both treatment groups.

CONCLUSIONS

In ambulatory adults on antiepileptic drugs, high-dose vitamin D therapy substantially increased bone mineral density at several skeletal sites. In children, both doses resulted in comparable increases in bone mass.

A novel inhibitor of the STAT3 pathway induces apoptosis in malignant glioma cells both in vitro and in vivo

Signal transducer and activator of transcription-3 (STAT3) is constitutively activated in a variety of cancer types, including malignant gliomas. STAT3 is activated by phosphorylation of a tyrosine residue, after which it dimerizes and translocates into the nucleus. There it regulates the expression of several genes responsible for proliferation and survival at the transcriptional level. A selective inhibitor of STAT3 phosphorylation, AG490, has been shown to inhibit growth and induce apoptosis in some cancer cell types. However, although AG490 routinely shows in vitro anticancer activity, it has not consistently demonstrated an in vivo anticancer effect in animal models. Here, we have tested WP1066, a novel inhibitor structurally related to AG490 but significantly more potent and active, against human malignant glioma U87-MG and U373-MG cells in vitro and in vivo. IC(50) values for WP1066 were 5.6 muM in U87-MG cells and 3.7 muM in U373-MG cells, which represents 18-fold and eightfold increases in potency, respectively, over that of AG490. WP1066 activated Bax, suppressed the expression of c-myc, Bcl-X(L) and Mcl-1, and induced apoptosis. Systemic intraperitoneal administration of WP1066 in mice significantly (P<0.001) inhibited the growth of subcutaneous malignant glioma xenografts during the 30-day follow-up period. Immunohistochemical analysis of the excised tumors revealed that phosphorylated STAT3 levels in the WP1066 treatment group remained inhibited at 3 weeks after the final WP1066 injection, whereas tumors from the control group expressed high levels of phosphorylated STAT3. We conclude that WP1066 holds promise as a therapeutic agent against malignant gliomas.

Hypercalcemia in glioblastoma multiforme

Hypercalcemia is commonly associated with cancer, occurring in around 10-20% of cancer patients. Hypercalcemia is usually related to solid and non-solid malignancies specifically breast cancer, lung cancer and multiple myeloma. Hypercalcemia has been reported to occur in association with astrocytomas, and uncommonly in gliomas. We report a case of a previously healthy man presenting with glioblastoma multiforme . He was found to have persistently elevated serum calcium and calcitriol with normal parathyroid function. This is the first reported case of hypercalcemia associated with glioblastoma multiforme.

Clinicopathological correlation (CC) and outcome of breast cancer patients (pts) with resected brain metastasis (BM)

656

Background: We aimed at determining the pathologic features of metastatic breast lesions to the brain, and their correlation with the primary tumor, and their effect on postneurosurgical survival (PNS). Methods: Tissue samples from 123 pts who underwent surgical resection of BM at MDACC between 1984–2004, were examined for estrogen receptor-α (ER) by IHC and HER2 by FISH or IHC. Pts’ medical records were retrospectively reviewed for CC. Results: Median (med) age at BM diagnosis was 51 years. The med time from primary diagnosis to BM was 33 months (Range (R)0–304). Infiltrating ductal cancers were found in 89%. ER was negative and HER2 amplified in 73% and 37% of BM, respectively; ER-/Her2- was seen in 43%, ER-/Her2+ in 30%, ER+/Her2+ in 6%. Concordance of ER and HER2 status between primary and BM were both 88% (p=NS, for discordance). ER positivity was associated with a longer primary diagnosis to BM interval [med 39 months (R, 0–213) vs. 29 months (R, 0–304) in the ER- pts; p=0.02]; HER2 amplification was not (p=0.82). The med PNS was 11.2 months (R, 9.0–13.5) for 112 pts with no pre- craniotomy brain radiation. Pts with ER+ metastases experienced apparent longer PNS survival than ER- pts [med 18.9 months (95% CI, 4.8–33.1) vs. 9.9 months (95% CI, 7.6–12.1 months), respectively, p=0.06], as did those with HER2-amplified BM [med 13.8 months vs. 9.9 months, respectively; p=0.10]. Pts aged 45 to <60 years had significantly longer pns survival (med 15.5 months) than younger or older pts (med 9.5 and 5.1 months, respectively), p≤.05 for all pair- wise comparisons. In mutivariate analyses correcting for age, functional status, and systemic tumor burden, neither ER nor HER2 status were independent predictors of pns. Of the 38 patients with HER2-amplified tumors and no pre- craniotomy radiation, 14 received trastuzumab (Tz) prior to initial neurosurgery. These 14 pts had longer PNS compared to those with HER2-amplified tumors not receiving Tz [median, 25.4 months vs. 10.7 months, respectively, p=NS). Conclusions: ER and HER2 positivity were highly concordant between primary and BM. Resected BM were more likely to be ER- or HER2-amplified. ER positivity and HER2 amplification were not significant independent predictors of PNS, though both showed a strong trend in univariate analyses. Middle age group pts had the best PNS survival.

No significant financial relationships to disclose.

Tumor-specific peptide vaccination in newly-diagnosed patients with GBM

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Background: Despite multimodality approaches, survival with GBM is dismal. Induction of immune responses to suppress the infiltrative, residual component with an easily manufactured and administered immunotherapy has been a theoretical ideal. The epidermal growth factor receptor variant III (EGFRvIII) is a tumor-specific cell surface protein expressed on approximately 40% of GBMs. Methods: Newly-diagnosed GBM patients with a gross-total resection, a KPS ≥70, and EGFRvIII+, after undergoing radiation with concurrent temozolomide without tumor progression, were eligible to receive EGFRvIII peptide vaccination i.d. with GM-CSF. Primary endpoint was safety. Results: Accrual began in 06/14/2004 and is now complete. 19 patients were enrolled. Median follow-up is 18 months. Toxicity was minimal and without evidence of autoimmunity. Humoral and cellular immune responses were generated. Median TTP from surgery in vaccine-treated patients is 12 months (n = 12), comparing favorably with a historical matched unvaccinated cohort (gross total resection without progression during radiation, KPS≥70, EGFRvIII+) that had a median TTP of 7.1 months (n = 39) (p = 0.0058). These results also compared favorably with those reported for concurrent temozolomide and radiation followed by adjuvant temozolomide, with a median TTP of 6.9 months. Median survival in this trial has exceeded 18 months which compares favorably to all published analyses accounting for all known prognostic indicators. Among recurrent tumors evaluated by immunohistochemistry, 100% no longer expressed the EGFRvIII, suggesting immunological activation that eliminated EGFRvIII-expressing cells, as well as one potential mechanism of treatment failure. Conclusions: EGFRvIII peptide vaccination warrants further investigation in a larger randomized clinical trial in patients with EGFRvIII-expressing tumors.

No significant financial relationships to disclose.

Ionizing radiation induces apoptosis and inhibits neuronal differentiation in rat neural stem cells via the c-Jun NH2-terminal kinase (JNK) pathway

A substantial number of neural stem cells (NSCs) continue to proliferate and generate neurons in the central nervous system throughout life. Ionizing radiation, an important adjuvant therapy for glioma patients, may damage NSCs and cause neuronal deficits, such as cognitive dysfunction and memory impairment. However, the precise mechanism of radiation effects on death and differentiation of NSCs remains largely unknown. Here, we found that radiation induced apoptosis in NSCs via the mitochondrial pathway, upregulating the ratio of Bax to Bcl-2 and releasing cytochrome c into the cytoplasm. Radiation also inhibited neuronal differentiation of NSCs by 50%. Of the three stress-associated mitogen-activated protein kinases (MAPKs), only c-Jun NH(2)-terminal kinase (JNK) was activated in NSCs after radiation. Interestingly, JNK inhibition by the specific inhibitor SP600125 rescued NSCs from apoptosis and improved neuronal differentiation. Furthermore, we examined whether radiation directly inhibits neuronal differentiation or not. Radiation did not affect the promoter activity of NeuroD, a basic helix-loop-helix transcription factor that regulates the expression of neuronal differentiation markers. Radiation induced more apoptosis in NeuroD-positive cells than NeuroD-negative cells. We concluded that radiation activates JNK and induces apoptosis, especially in neural progenitor cells, resulting in the inhibition of neurogenesis. Our findings raise the possibility that JNK inhibition has therapeutic potential in protecting NSCs from the adverse effects of radiation.

Effect of antiepileptic drugs on bone density in ambulatory patients

BACKGROUND

Long-term antiepileptic drug (AED) use causes multiple abnormalities in calcium and bone metabolism that have been most extensively described in institutionalized patients. The objective is to determine the effect of AED on vitamin D levels and bone density in ambulatory patients and to compare the effects of enzyme-inducing and -noninducing AED and of single vs multiple therapy on bone density.

METHODS

A cross-sectional evaluation was conducted of 71 patients (42 adults and 29 children/adolescents) on anticonvulsant therapy for at least 6 months who presented to neurologists at a tertiary referral center. Bone mineral density (BMD) as well as serum 25 hydroxy-vitamin D (25-OHD) levels were measured. A detailed questionnaire assessing calcium intake as well as previous and current intake of antiepileptic medications was administered to all patients.

RESULTS

Over 50% of adults and children/adolescents had low 25-OHD levels, but this finding did not correlate with BMD. Antiepileptic therapy decreased BMD in adults. Generalized seizures, duration of epilepsy, and polypharmacy were significant determinants of BMD, more so at skeletal sites enriched in cortical bone. Subjects on enzyme-inducing drugs such as phenytoin, phenobarbital, carbamazepine, and primidone tended to have lower BMD than those on noninducers such as valproic acid, lamotrigine, clonazepam, gabapentin, topamirate, and ethosuximide.

CONCLUSION

Epilepsy and its therapy, including the newer drugs, are risk factors for low bone density, irrespective of vitamin D levels. Skeletal monitoring with the institution of appropriate therapy is indicated in patients on chronic antiepileptic therapy.

Surgical management of brain metastases

Metastatic brain tumors are the most common intracranial tumors in adults and the most common cause of neurologic morbidity and mortality in these patients. Recent advances in the management of the primary cancer have resulted in improved prognosis, longer survival, and thus, increased identification of the presence of brain metastases. Data suggest that aggressive treatment of the metastatic brain tumor with surgical resection increases the length of survival in these patients. New techniques, including preoperative functional imaging, stereotactic surgical resection, image-guided neurosurgery, intraoperative ultrasound, and cortical mapping, have aided neurosurgeons in surgical resection and have helped to lower the associated surgical morbidity and mortality. The respective roles of surgery, patient selection, prognostic factors, and radiotherapy are addressed in this review.

Surgical resection of intrinsic insular tumors: complication avoidance

OBJECT

Surgical resection of tumors located in the insular region is challenging for neurosurgeons, and few have published their surgical results. The authors report their experience with intrinsic tumors of the insula, with an emphasis on an objective determination of the extent of resection and neurological complications and on an analysis of the anatomical characteristics that can lead to suboptimal outcomes.

METHODS

Twenty-two patients who underwent surgical resection of intrinsic insular tumors were retrospectively identified. Eight tumors (36%) were purely insular, eight (36%) extended into the temporal pole, and six (27%) extended into the frontal operculum. A transsylvian surgical approach, combined with a frontal opercular resection or temporal lobectomy when necessary, was used in all cases. Five of 13 patients with tumors located in the dominant hemisphere underwent craniotomies while awake. The extent of tumor resection was determined using volumetric analyses. In 10 patients, more than 90% of the tumor was resected; in six patients, 75 to 90% was resected; and in six patients, less than 75% was resected. No patient died within 30 days after surgery. During the immediate postoperative period, the neurological conditions of 14 patients (64%) either improved or were unchanged, and in eight patients (36%) they worsened. Deficits included either motor or speech dysfunction. At the 3-month follow-up examination, only two patients (9%) displayed permanent deficits. Speech and motor dysfunction appeared to result most often from excessive opercular retraction and manipulation of the middle cerebral artery (MCA), interruption of the lateral lenticulostriate arteries (LLAs), interruption of the long perforating vessels of the second segment of the MCA (M2), or violation of the corona radiata at the superior aspect of the tumor. Specific methods used to avoid complications included widely splitting the sylvian fissure and identifying the bases of the periinsular sulci to define the superior and inferior resection planes, identifying early the most lateral LLA to define the medial resection plane, dissecting the MCA before tumor resection, removing the tumor subpially with preservation of all large perforating arteries arising from posterior M2 branches, and performing craniotomy with brain stimulation while the patient was awake.

CONCLUSIONS

A good understanding of the surgical anatomy and an awareness of potential pitfalls can help reduce neurological complications and maximize surgical resection of insular tumors.