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Indication for surgical treatment in patients with intracranial meningioma must include both clinical aspects and an individual risk-benefit stratification, especially in geriatric patients. Prolonged mechanical ventilation (PMV) has not been investigated for its potential effects in patients with meningioma. We therefore analyzed the impact of PMV on mortality in geriatric patients who had undergone meningioma resection. Between 2009 and 2019, 261 patients aged ≥ 70 years were surgically treated for intracranial meningioma at our institution. PMV was defined as postoperative invasive ventilation of >7 days. Postoperative PMV was present in 17 of 261 geriatric meningioma patients (7%). Twenty-five geriatric patients (10%) died within 1 year after surgery. A scoring system ("ACKT") based on the variables of age, preoperative C-reactive protein (CRP) value, Karnofsky performance scale and tumor size supports prediction of postoperative PMV (sensitivity 73%, specificity 84%). PMV is significantly associated with increased mortality after surgical treatment of meningiomas in geriatric patients. Furthermore, we suggest a novel score ("ACKT") to preoperatively estimate the risk of PMV occurrence, which might help to guide future risk-benefit assessment and patient counseling in the geriatric meningioma population.

History: A 82-years old woman was admitted with a progressive cognitive decline for further investigations and treatment., Findings and Diagnosis: In the computed tomography of the brain findings of subcortical artherosclerotic encephalopathy (SAE) were present. Laboratory findings revealed elevated hemoglobin-levels (19.9 g/dl). In further investigations we found a mutation in JAK-2 as diagnostic sign for polycythemia vera (Pv). After specific treatment of the Pv cognition improved significantly., Discussion: In this case report we were able to relate the progressive cognitive impairment in the context of newly diagnosed Pv in conjunction with pre-existing SAE. After Pv-directed therapy cognition improved. This case report underlines the importance of a good diagnostic work-up of patients with cognitive impairment to rule out secondary and possible treatable causes., Competing Interests: Die Autorinnen/Autoren geben an, dass kein Interessenkonflikt besteht., (Thieme. All rights reserved.)

Object: Increasing age is a known negative prognostic factor for glioblastoma. However, a multifactorial approach is necessary to achieve optimal neuro-oncological treatment. It remains unclear to what extent frailty, comorbidity burden, and obesity might exert influence on survival in geriatric glioblastoma patients. We have therefore reviewed our institutional database to assess the prognostic value of these factors in elderly glioblastoma patients., Methods: Between 2012 and 2018, patients aged ≥ 65 years with newly diagnosed glioblastoma were included in this retrospective analysis. Patients frailty was analyzed using the modified frailty index (mFI), while patients comorbidity burden was assessed according to the Charlson comorbidity index (CCI). Body mass index (BMI) was used as categorized variable., Results: A total of 110 geriatric patients with newly diagnosed glioblastoma were identified. Geriatric patients categorized as least-frail achieved a median overall survival (mOS) of 17 months, whereas most frail patients achieved a mOS of 8 months (p = 0.003). Patients with a CCI > 2 had a lower mOS of 6 months compared to patients with a lower comorbidity burden (12 months; p = 0.03). Multivariate analysis identified "subtotal resection" (p = 0.02), "unmethylated MGMT promoter status" (p = 0.03), "BMI < 30" (p = 0.04), and "frail patient (mFI ≥ 0.27)" (p = 0.03) as significant and independent predictors of 1-year mortality in geriatric patients with surgical treatment of glioblastoma (Nagelkerke's R 2 0.31)., Conclusions: The present study concludes that both increased frailty and comorbidity burden are significantly associated with poor OS in geriatric patients with glioblastoma. Further, the present series suggests an obesity paradox in geriatric glioblastoma patients.

Objectives: To compare the CARG (Cancer and Aging Research Group) and CRASH (Chemotherapy Risk Assessment Scale for High-Age Patients) score regarding the predictive performance for severe toxicity in older patients with cancer., Methods: We recruited patients ≥70 years and applied the CARG and CRASH score before the start of systemic cancer treatment. The CARG predicts severe overall toxicity; the CRASH additionally predicts hematologic and nonhematologic toxicity. We captured ≥ grade 3 toxicity according to Common Terminology Criteria for Adverse Events (CTCAE) from medical records. Predictive performance was assessed using logistic regression and the area under the receiver operating characteristic curve (ROC-AUC)., Results: The study cohort comprised 120 patients (50% female, mean age 77.2 years, 57% solid tumors). The median of the CARG (range 0-23) and the combined CRASH (range 0-12) were 9 and 8, respectively. 81% of patients experienced toxicity; 67% showed hematologic toxicity. The predictive performance of the CARG and the combined CRASH was similar for overall toxicity (CARG: Odds ratio per unit increase (OR) 1.266, P = .015; ROC-AUC 0.681, P = .010; combined CRASH: OR 1.337, P = .029; ROC-AUC 0.650, P = .032). For hematologic toxicity, the hematologic CRASH was a significant predictor and showed numerically a higher ROC-AUC than the CARG which was not statistically different (CARG: OR 1.048, P = .462; ROC-AUC 0.564, P = .271; hematologic CRASH: OR 1.602, P = .007; ROC-AUC 0.665, P = .005)., Conclusion: Both scores exhibited similar predictive performance for toxicity in older patients with cancer., Competing Interests: Declaration of Competing Interest IO, MK, CS have nothing to disclose. UJ, AHJ, YDK report grants from the Herbert-Worch foundation during the conduct of the study. MMO reports as financial activities outside the submitted work being currently employed at Grünenthal GmbH, however this was not the case during her main contribution to this study., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Geriatric medicine is a rapidly evolving field that addresses diagnostic, therapeutic and care aspects of older adults. Some disabilities and disorders affecting cognition (e.g. dementia), motor function (e.g. stroke, Parkinson's disease, neuropathies), mood (e.g. depression), behavior (e.g. delirium) and chronic pain disorders are particularly frequent in old subjects. As knowledge about these age-associated conditions and disabilities is steadily increasing, the integral implementation of neurogeriatric knowledge in geriatric medicine and specific neurogeriatric research is essential to develop the field. This article discusses how neurological know-how could be integrated in academic geriatric medicine to improve care of neurogeriatric patients, to foster neurogeriatric research and training concepts and to provide innovative care concepts for geriatric patients with predominant neurological conditions and disabilities.

The sigma 1 receptor (S1R) is widely expressed in the CNS and is mainly located on the endoplasmic reticulum. The S1R is involved in the regulation of many neurotransmission systems and, indirectly, in neurodegenerative diseases. The S1R may therefore represent an interesting neuronal biomarker in neurodegenerative diseases such as Parkinson's (PD) or Alzheimer's diseases (AD). Here we present the characterisation of the S1R-specific 18 F-labelled tracer 18 F-IAM6067 in two animal models and in human brain tissue. Methods: Wistar rats were used for PET-CT imaging (60 min dynamic acquisition) and metabolite analysis (1, 2, 5, 10, 20, 60 min post-injection). To verify in vivo selectivity, haloperidol, BD1047 (S1R ligand), CM398 (S2R ligand) and SB206553 (5HT 2B/C antagonist) were administrated for pre-saturation studies. Excitotoxic lesions induced by intra-striatal injection of AMPA were also imaged by 18 F-IAM6067 PET-CT to test the sensitivity of the methods in a well-established model of neuronal loss. Tracer brain uptake was also verified by autoradiography in rats and in a mouse model of PD (intrastriatal 6-hydroxydopamine (6-OHDA) unilateral lesion). Finally, human cortical binding was investigated by autoradiography in three groups of subjects (control subjects with Braak ≤2, and AD patients, Braak >2 & ≤4 and Braak >4 stages). Results: We demonstrate that despite rapid peripheral metabolism of 18 F-IAM6067, radiolabelled metabolites were hardly detected in brain samples. Brain uptake of 18 F-IAM6067 showed differences in S1R anatomical distribution, namely from high to low uptake: pons-raphe, thalamus medio-dorsal, substantia nigra , hypothalamus, cerebellum, cortical areas and striatum. Pre-saturation studies showed 79-90% blockade of the binding in all areas of the brain indicated above except with the 5HT 2B/C antagonist SB206553 and S2R ligand CM398 which induced no significant blockade, indicating good specificity of 18 F-IAM6067 for S1Rs. No difference between ipsi- and contralateral sides of the brain in the mouse model of PD was detected. AMPA lesion induced a significant 69% decrease in 18 F-IAM6067 uptake in the globus pallidus matching the neuronal loss as measured by NeuN, but only a trend to decrease (-16%) in the caudate putamen despite a significant 91% decrease in neuronal count. Moreover, no difference in the human cortical binding was shown between AD groups and controls. Conclusion: This work shows that 18 F-IAM6067 is a specific and selective S1R radiotracer. The absence or small changes in S1R detected here in animal models and human tissue warrants further investigations and suggests that S1R might not be the anticipated ideal biomarker for neuronal loss in neurodegenerative diseases such as AD and PD., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

The tumour microenvironment (TME) surrounding tumour cells is a highly dynamic and heterogeneous composition of immune cells, fibroblasts, precursor cells, endothelial cells, signalling molecules and extracellular matrix (ECM) components. Due to the heterogeneity and the constant crosstalk between the TME and the tumour cells, the components of the TME are important prognostic parameters in cancer and determine the response to novel immunotherapies. To improve the characterization of the TME, novel non-invasive imaging paradigms targeting the complexity of the TME are urgently needed.The characterization of the TME by molecular imaging will (1) support early diagnosis and disease follow-up, (2) guide (stereotactic) biopsy sampling, (3) highlight the dynamic changes during disease pathogenesis in a non-invasive manner, (4) help monitor existing therapies, (5) support the development of novel TME-targeting therapies and (6) aid stratification of patients, according to the cellular composition of their tumours in correlation to their therapy response.This chapter will summarize the most recent developments and applications of molecular imaging paradigms beyond FDG for the characterization of the dynamic molecular and cellular changes in the TME.

Purpose: The P2X7 receptor (P2X7R) is an ATP-gated ion channel predominantly expressed on activated microglia and is important in neurodegenerative diseases including Parkinson's disease (PD). In this first-in-human study, we investigated [ 11 C]JNJ54173717 ([ 11 C]JNJ717), a selective P2X7R tracer, in healthy volunteers (HV) and PD patients. Biodistribution, dosimetry, kinetic modelling and short-term test-retest variation (TRV), as well as possible genotype effects, were investigated., Methods: Biodistribution and radiation dosimetry studies were performed in three HV (mean age 30 ± 2 years, two women) using whole-body PET/CT. The most appropriate kinetic model was determined in 11 HV (mean age 62 ± 10 years, six women) and 10 PD patients (mean age 64 ± 8 years, three women; mean UPDRS motor score 21 ± 8) using 90-min dynamic simultaneous PET/MR scans. The total volume of distribution (V T ) was calculated using a one-tissue and a two-tissue compartment model (1TCM, 2TCM) and Logan graphical analysis, and its time stability was assessed. Seven subjects underwent retest scans (mean age 60 ± 13 years, four HV, one woman). A group analysis was performed to compare PD patients and HV. Finally, 13 exons of P2X7R were genotyped in all subjects included in the second part of the study., Results: The mean effective dose was 4.47 ± 0.32 μSv/MBq, with the highest absorbed doses to the gallbladder, liver and small intestine. A reversible 2TCM was the most appropriate kinetic model with relatively homogeneous V T values in the grey and white matter. Average V T values were 3.4 ± 0.8 in HV and 3.3 ± 0.7 in PD patients, with no significant difference between the groups, but a possible genotype effect (rs3751143) was identified which can affect V T . Average TRV was 10-15%. The stability of V T over time allowed a reduction in scan time to 70 min., Conclusion: [ 11 C]JNJ717 is safe and suitable for quantifying P2X7R expression in human brain. In this pilot study, no significant differences in P2X7R binding were found between HV and PD patients. The results also suggest that genotype effects need to be incorporated in future P2X7R PET analyses.

Recent studies in neurodegenerative conditions have increasingly highlighted that the same neuropathology can trigger different clinical phenotypes or, vice-versa, that similar phenotypes can be triggered by different neuropathologies. This evidence has called for the adoption of a pathology spectrum-based approach to study neurodegenerative proteinopathies. These conditions share brain deposition of abnormal protein aggregates, leading to aberrant biochemical, metabolic, functional, and structural changes. Positron emission tomography (PET) is a well-recognized and unique tool for the in vivo assessment of brain neuropathology, and novel PET techniques are emerging for the study of specific protein species. Today, key applications of PET range from early research and clinical diagnostic tools to their use in clinical trials for both participants screening and outcome evaluation. This position article critically reviews the role of distinct PET molecular tracers for different neurodegenerative proteinopathies, highlighting their strengths, weaknesses, and opportunities, with special emphasis on methodological challenges and future applications., (Copyright © 2019 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

As a result of the aging population dementia is a growing challenge, especially in healthcare. Nevertheless, cognitive disorders are often not systematically evaluated, especially during hospital stays for other reasons; however, cognitive impairment is associated with a number of geriatric syndromes, including falls, delirium, dysphagia and lack of adherence to treatment plans. This article considers the current state of diagnosis and treatment of dementia. Non-pharmacological therapeutic approaches as well as current and future pharmacological treatment options are discussed. The drugs of choice for the symptomatic treatment of cognitive deficits in Alzheimer's disease and Parkinson-associated dementia are cholinesterase inhibitors and memantine; there is no specific pharmacological treatment for other types of dementia. Prevention and treatment of cardiovascular risk factors can potentially retard the progression of possibly all forms of dementia.

Introduction: A rapid transition from a clinical-based classification to a pathology-based classification of neurodegenerative conditions, largely promoted by the increasing availability of imaging biomarkers, is emerging. The Framework for Innovative Multi-tracer molecular Brain Imaging, funded by the EU Joint Program - Neurodegenerative Disease Research 2016 "Working Groups for Harmonisation and Alignment in Brain Imaging Methods for Neurodegeneration," aimed at providing a roadmap for the applications of established and new molecular imaging techniques in dementia., Methods: We consider current and future implications of adopting a pathology-based framework for the use and development of positron emission tomography techniques., Results: This approach will enhance efforts to understand the multifactorial etiology of Alzheimer's disease and other dementias., Discussion: The availability of pathology biomarkers will soon transform clinical and research practice. Crucially, a comprehensive understanding of strengths and caveats of these techniques will promote an informed use to take full advantage of these tools.

Background : Activation and dysregulation of innate, adaptive and resident immune cells in response to damage determine the pathophysiology of demyelinating disorders. Among the plethora of involved cells, microglia/macrophages and astrocytes play an important role in the pathogenesis of demyelinating disorders. The in-depth investigation of the spatio-temporal profile of these cell types in vivo may inform about the exact disease state and localization as well as may allow to monitor therapeutic modulation of the components of the neuroinflammatory response during the course of multiple sclerosis (MS). In this study, we aimed to non-invasively decipher the degree and temporal profile of neuroinflammation (TSPO - [ 18 F]DPA-714 PET) in relation to selected magnetic resonance imaging (MRI) parameters (T 2 maps) in the cuprizone (CPZ)-induced model of demyelination. Methods: C57Bl6 ( n=30 ) mice were fed with a standard chow mixed with 0.2% (w/w) CPZ for 4 ( n=10 ; demyelination) and 6 weeks ( n=10 ; spontaneous remyelination). The degree of neuroinflammation at de- and remyelination was assessed by [ 18 F]DPA-714 PET, multi-echo T 2 MRI, autoradiography and immunohistochemistry. Results : CPZ-induced brain alterations were confirmed by increase of T 2 relaxation times in both white and grey matter after 3 and 5 weeks of CPZ. Peak [ 18 F]DPA-714 was found in the corpus callosum (CC, white matter), the hippocampus (HC, grey matter) and thalamus (grey matter) after 4 weeks of CPZ treatment and declined after 6 weeks of CPZ. Ex vivo autoradiography and dedicated immunofluorescence showed demyelination/remyelination with corresponding increased/decreased TSPO levels in the CC and hippocampus, confirming the spatial distribution of [ 18 F]DPA-714 in vivo . The expression of TSPO microglia and astrocytes is time-dependent in this model. Microglia predominantly express TSPO at demyelination, while the majority of astrocytes express TSPO during remyelination. The combination of PET- and MRI-based imaging biomarkers demonstrated the regional and temporal development of the CPZ model-associated neuroinflammatory response in grey and white matter regions. Conclusions : The combination of [ 18 F]DPA-714 PET and T 2 mapping may allow to further elucidate the regional and temporal profile of inflammatory signals depending on the myelination status, although the underlying inflammatory microenvironment changes. A combination of the described imaging biomarkers may facilitate the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in MS., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.

History and Clinical Findings: We present a 86-year-old patient who suffered from progressive weakness in his right leg. Due to a hypercholesterinemia he had received Simvastatin for a few years. Because of higher cholesterine levels the dosis had been increased from 40 to 80 mg 6 months ago., Investigations and Diagnosis: We saw elevated levels of creatinine kinase and creatinine. In the EMG, a neuromuscular impairment was detected. In context with the medical history we could make the diagnosis of a statin-induced myopathy with rhabdomyolysis., Treatment and Course: After stopping the medication with statin and under liquid substitution, creatinine kinase and creatinine levels dropped. After therapy the weakness of the leg was totally recurrent., Conclusion: In case of unclear neurological symptoms and under therapy with statins, a myopathy should be considered., Competing Interests: Disclosure The authors report no conflicts of interest in this work., (© Georg Thieme Verlag KG Stuttgart · New York.)

Noninvasive monitoring of tumor therapy response helps in developing personalized treatment strategies. Here, we performed sequential PET and diffusion-weighted MRI to evaluate changes induced by a FOLFOX-like combination chemotherapy in colorectal cancer xenografts, to identify the cellular and molecular determinants of these imaging biomarkers. Methods: Tumor-bearing CD1 nude mice, engrafted with FOLFOX-sensitive Colo205 colorectal cancer xenografts, were treated with FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin) weekly. On days 1, 2, 6, 9, and 13 of therapy, tumors were assessed by in vivo imaging and ex vivo analyses. In addition, HCT116 xenografts, which did not respond to the FOLFOX treatment, were imaged on day 1 of therapy. Results: In Colo205 xenografts, FOLFOX induced a profound increase in uptake of the proliferation PET tracer 3'-deoxy-3'- 18 F-fluorothymidine ( 18 F-FLT) accompanied by increases in markers for proliferation (Ki-67, thymidine kinase 1) and for activated DNA damage response (γH2AX), whereas the effect on cell death was minimal. Because tracer uptake was unaltered in the HCT116 model, these changes appear to be specific for tumor response. Conclusion: We demonstrated that 18 F-FLT PET can noninvasively monitor cancer treatment-induced molecular alterations, including thymidine metabolism and DNA damage response. The cellular or imaging changes may not, however, be directly related to therapy response as assessed by volumetric measurements., (© 2018 by the Society of Nuclear Medicine and Molecular Imaging.)

Purpose: We recently reported that high thymidine phosphorylase (TP) expression is accompanied by low tumor thymidine concentration and high 3'-deoxy-3'-[ 18 F]fluorothymidine ([ 18 F]FLT) uptake in four untreated lung cancer xenografts. Here, we investigated whether this relationship also holds true for a broader range of tumor models., Procedures: Lysates from n = 15 different tumor models originating from n = 6 institutions were tested for TP and thymidylate synthase (TS) expression using western blots. Results were correlated to [ 18 F]FLT accumulation in the tumors as determined by positron emission tomography (PET) measurements in the different institutions and to previously published thymidine concentrations., Results: Expression of TP correlated positively with [ 18 F]FLT SUV max (ρ = 0.549, P < 0.05). Furthermore, tumors with high TP levels possessed lower levels of thymidine (ρ = - 0.939, P < 0.001)., Conclusions: In a broad range of tumors, [ 18 F]FLT uptake as measured by PET is substantially influenced by TP expression and tumor thymidine concentrations. These data strengthen the role of TP as factor confounding [ 18 F]FLT uptake.

The value of combined L-( methyl-[ 11 C]) methionine positron-emitting tomography (MET-PET) and magnetic resonance imaging (MRI) with regard to tumor extent, entity prediction, and therapy effects in clinical routine in patients with suspicion of a brain tumor was investigated. In n = 65 patients with histologically verified brain lesions n = 70 MET-PET and MRI (T1-weighted gadolinium-enhanced [T1w-Gd] and fluid-attenuated inversion recovery or T2-weighted [FLAIR/T2w]) examinations were performed. The computer software "visualization and analysis framework volume rendering engine (Voreen)" was used for analysis of extent and intersection of tumor compartments. Binary logistic regression models were developed to differentiate between World Health Organization (WHO) tumor types/grades. Tumor sizes as defined by thresholding based on tumor-to-background ratios were significantly different as determined by MET-PET (21.6 ± 36.8 cm 3 ), T1w-Gd-MRI (3.9 ± 7.8 cm 3 ), and FLAIR/T2-MRI (64.8 ± 60.4 cm 3 ; P < .001). The MET-PET visualized tumor activity where MRI parameters were negative: PET positive tumor volume without Gd enhancement was 19.8 ± 35.0 cm 3 and without changes in FLAIR/T2 10.3 ± 25.7 cm 3 . FLAIR/T2-MRI visualized greatest tumor extent with differences to MET-PET being greater in posttherapy (64.6 ± 62.7 cm 3 ) than in newly diagnosed patients (20.5 ± 52.6 cm 3 ). The binary logistic regression model differentiated between WHO tumor types (fibrillary astrocytoma II n = 10 from other gliomas n = 16) with an accuracy of 80.8% in patients at primary diagnosis. Combined PET and MRI improve the evaluation of tumor activity, extent, type/grade prediction, and therapy-induced changes in patients with glioma and serve information highly relevant for diagnosis and management.

The positron emission tomography (PET) tracer 3'-deoxy-3'-[ 18 F]fluorothymidine ([ 18 F]FLT) has been proposed to measure cell proliferation non-invasively in vivo . Hence, it should provide valuable information for response assessment to tumor therapies. To date, [ 18 F]FLT uptake has found limited use as a response biomarker in clinical trials in part because a better understanding is needed of the determinants of [ 18 F]FLT uptake and therapy-induced changes of its retention in the tumor. In this systematic review of preclinical [ 18 F]FLT studies, comprising 174 reports, we identify the factors governing [ 18 F]FLT uptake in tumors, among which thymidine kinase 1 plays a primary role. The majority of publications (83 %) report that decreased [ 18 F]FLT uptake reflects the effects of anticancer therapies. 144 times [ 18 F]FLT uptake was related to changes in proliferation as determined by ex vivo analyses. Of these approaches, 77 % describe a positive relation, implying a good concordance of tracer accumulation and tumor biology. These preclinical data indicate that [ 18 F]FLT uptake holds promise as an imaging biomarker for response assessment in clinical studies. Understanding of the parameters which influence cellular [ 18 F]FLT uptake and retention as well as the mechanism of changes induced by therapy is essential for successful implementation of this PET tracer. Hence, our systematic review provides the background for the use of [ 18 F]FLT in future clinical studies., Competing Interests: The authors have declared that no competing interest exists.

Purpose: Resistance to bevacizumab (BEV) in glioblastoma is believed to occur via activation of molecular networks including the mTOR/PI3K pathway. Using an MR/PET molecular imaging biomarker approach, we investigated the response to combining BEV with the mTOR/PI3K inhibitor BEZ235., Methods: Tumours were established by orthotopically implanting U87MG-luc2 cells in mice. Animals were treated with BEZ235 and/or BEV, and imaged using diffusion-weighted-MRI, T2-weighted and T2*-weighted before and after administration of superparamagnetic iron oxide contrast agent. Maps for changes in relaxation rates (ΔR2, ΔR2* and apparent diffusion coefficient) were calculated. Vessel size index and microvessel density index were derived. 3'-Deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) PET and O-(2-[(18)F]fluoroethyl)-L-tyrosine ([(18)F]FET) PET were further performed and tumour endothelium/proliferation markers assessed by immunohistochemistry., Results: Treatment with BEV resulted in a pronounced decrease in tumour volume (T2-weighted MRI). No additive effect on tumour volume was observed with the BEV/BEZ235 combination compared with BEV monotherapy. The Ki67 proliferation index and [(18)F]FLT uptake studies were used to support the observations. Using ΔR2* and ΔR2 values, respectively, the BEV/BEZ235 combination significantly reduced tumour microvessel volume in comparison to BEV alone. Decreased microvessel density index was further observed in animals treated with the combination, supported by von Willebrand factor (vWF) immunohistochemistry. [(18)F]FET uptake was decreased following treatment with BEV alone, but was not further reduced following treatment with the combination. vWF immunohistochemistry analysis showed that the mean tumour vessel size was increased in all cohorts., Conclusion: Assessing MR imaging biomarker parameters together with [(18)F]FET and [(18)F]FLT PET provided information on mechanism of action of the drug combination and clues as to potential clinical responses. Following translation to clinical use, treatment with a BEV/BEZ235 combination could reduce peritumoral oedema obviating the requirement for steroids. The use of hypothesis-driven molecular imaging studies facilitates the preclinical evaluation of drug response. Studies of this kind may more accurately predict the clinical potential of the BEV/BEZ235 combination regimen as a novel therapeutic approach in oncology.

Purpose: To evaluate between-site agreement of apparent diffusion coefficient (ADC) measurements in preclinical magnetic resonance imaging (MRI) systems., Materials and Methods: A miniaturized thermally stable ice-water phantom was devised. ADC (mean and interquartile range) was measured over several days, on 4.7T, 7T, and 9.4T Bruker, Agilent, and Magnex small-animal MRI systems using a common protocol across seven sites. Day-to-day repeatability was expressed as percent variation of mean ADC between acquisitions. Cross-site reproducibility was expressed as 1.96 × standard deviation of percent deviation of ADC values., Results: ADC measurements were equivalent across all seven sites with a cross-site ADC reproducibility of 6.3%. Mean day-to-day repeatability of ADC measurements was 2.3%, and no site was identified as presenting different measurements than others (analysis of variance [ANOVA] P = 0.02, post-hoc test n.s.). Between-slice ADC variability was negligible and similar between sites (P = 0.15). Mean within-region-of-interest ADC variability was 5.5%, with one site presenting a significantly greater variation than the others (P = 0.0013)., Conclusion: Absolute ADC values in preclinical studies are comparable between sites and equipment, provided standardized protocols are employed., (© 2015 Wiley Periodicals, Inc.)

Unlabelled: In this report we describe a patient who developed liver failure due to new administration of pregabaline., History and Admission Findings: A 76-year old woman was admitted with a sacral fracture after conservative treatment in a trauma surgery ward for further rehabilitative treatment., Investigations: At admittance the patient complaint of lower back pain. Physical examination revealed unsteadiness in walking tests. Laboratory tests revealed mildly elevated infection parameters (CRP 0.67 mg / dl) and alkaline phosphatase (191U / I)., Treatment and Course: Physical training was initiated. Multimodal therapy for pain was continued with tilidin / naloxon, which had been started at the trauma surgery ward. Due to persistent pain and its radicular nature additional pregabaline treatment was initiated. Ten days thereafter the patient developed nausea without vomiting and subsequently (day 15) jaundice. Blood examination revealed elevated liver enzymes (ALT 246U / I, AST 86U / I, GGT 2068U / I and bilirubine 6 mg / dl). Abdominal sonography and MRCP were normal. After discontinuation of pregabaline treatment nausea disappeared within several days and liver enzymes declined to normal values within several weaks., Conclusion: Pregabaline should be taken into account as cause of acute liver failure., (© Georg Thieme Verlag KG Stuttgart · New York.)

Epigenomic changes are an important feature of malignant tumors. How tumor aggressiveness is affected by DNA methylation of specific loci is largely unexplored. In genome-wide DNA methylation analyses, we identified the KCa 3.1 channel gene (KCNN4) promoter to be hypomethylated in an aggressive non-small-cell lung carcinoma (NSCLC) cell line and in patient samples. Accordingly, KCa 3.1 expression was increased in more aggressive NSCLC cells. Both findings were strong predictors for poor prognosis in lung adenocarcinoma. Increased KCa 3.1 expression was associated with aggressive features of NSCLC cells. Proliferation and migration of pro-metastatic NSCLC cells depended on KCa 3.1 activity. Mechanistically, elevated KCa 3.1 expression hyperpolarized the membrane potential, thereby augmenting the driving force for Ca(2+) influx. KCa 3.1 blockade strongly reduced the growth of xenografted NSCLC cells in mice as measured by positron emission tomography-computed tomography. Thus, loss of DNA methylation of the KCNN4 promoter and increased KCa 3.1 channel expression and function are mechanistically linked to poor survival of NSCLC patients., (© 2015 UICC.)

Unlabelled: Molecular imaging allows the noninvasive assessment of cancer progression and response to therapy. The aim of this study was to investigate molecular and cellular determinants of 3'-deoxy-3'-(18)F-fluorothymidine ((18)F-FLT) PET and diffusion-weighted (DW) MR imaging in lung carcinoma xenografts., Methods: Four lung cancer cell lines (A549, HTB56, EBC1, and H1975) were subcutaneously implanted in nude mice, and growth was followed by caliper measurements. Glucose uptake and tumor proliferation were determined by (18)F-FDG and (18)F-FLT PET, respectively. T2-weighted MR imaging was performed, and the apparent diffusion coefficient (ADC) was determined by DW MR imaging as an indicator of cell death. Imaging findings were correlated to histology with markers for tumor proliferation (Ki67, 5-bromo-2'-deoxyuridine [BrdU]) and cell death (caspase-3, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling). The expression of human equilibrative nucleoside transporter 1 (hENT1), thymidine kinase 1 (TK1), thymidylate synthase, and thymidine phosphorylase (TP) were analyzed by Western blot and immunohistochemistry. Thymidine levels were determined by liquid chromatography-mass spectrometry., Results: Xenografts varied with respect to in vivo growth rates. MR imaging and PET revealed intratumoral heterogeneities, which were confirmed by histology. (18)F-FLT uptake differed significantly between tumor lines, with A549 and H1975 demonstrating the highest radiotracer accumulation (A549, 8.5 ± 3.2; HTB56, 4.4 ± 0.7; EBC1, 4.4 ± 1.2; and H1975, 12.1 ± 3.5 maximal percentage injected dose per milliliter). In contrast, differences in (18)F-FDG uptake were only marginal. No clear relationship between (18)F-FLT accumulation and immunohistochemical markers for tumor proliferation (Ki67, BrdU) as well as hENT1, TK1, or TS expression was detected. However, TP was highly expressed in A549 and H1975 xenografts, which was accompanied by low tumor thymidine concentrations, suggesting that tumor thymidine levels influence (18)F-FLT uptake in the tumor models investigated. MR imaging revealed higher ADC values within proliferative regions of H1975 and A549 tumors than in HTB56 and EBC1. These ADC values were negatively correlated with cell density but not directly related to cell death., Conclusion: A direct relationship of (18)F-FLT with proliferation or ADC with cell death might be complicated by the interplay of multiple processes at the cellular and physiologic levels in untreated tumors. This issue must be considered when using these imaging modalities in preclinical or clinical settings., (© 2014 by the Society of Nuclear Medicine and Molecular Imaging, Inc.)

Purpose: Angiogenesis is a key event in the progression of glioblastomas (GBM). Our goal was to measure different anatomical and physiological parameters of GBM vessels using steady-state contrast-enhanced magnetic resonance imaging (SSCE-MRI), together with the assessment of biochemical parameters on GBM proliferation and angiogenesis using [(11)C]methyl-L-methionine (MET) and 3'-deoxy-3'-[(18)F]fluorothymidine (FLT) and positron emission tomography (PET). We focused on how these anatomical and biochemical read-outs correlate with one another and with immunohistochemistry., Methods: SSCE-MRI together with (11)C-MET and (18)F-FLT PET were performed 3 weeks after intracranial implantation of human GBM spheroids in nude rats (n = 8). Total cerebral blood volume (tCBV), blood volume present in microvessels (μCBV), vessel density and size were calculated. Rats were treated with bevacizumab (n = 4) or vehicle (n = 4) for 3 weeks. Imaging was repeated at week 6, and thereafter immunohistochemistry was performed., Results: Three weeks after implantation, MRI showed an increase of vessel density and μCBV in the tumour compared to the contralateral brain. At week 6, non-treated rats showed a pronounced increase of (11)C-MET and (18)F-FLT tumour uptake. Between weeks 3 and 6, tCBV and vessel size increased, whereas vessel density and μCBV decreased. In rats treated with bevacizumab μCBV values were significantly smaller at week 6 than in non-treated rats, whereas the mean vessel size was higher. Accumulation of both radiotracers was lower for the treated versus the non-treated group. Most importantly, non-invasive measurement of tumour vessel characteristics and tumour proliferation correlated to immunohistochemistry findings., Conclusion: Our study demonstrates that SSCE-MRI enables non-invasive assessment of the anatomy and physiology of the vasculature of experimental gliomas. Combined SSCE-MRI and (11)C-MET/(18)F-FLT PET for monitoring biochemical markers of angiogenesis and proliferation in addition to vessel anatomy could be useful to improve our understanding of therapy response of gliomas.

The purpose of this positron emission tomography (PET) study was to compare the prognostic value of pretreatment volume of ¹¹C]-methionine (MET) uptake and semiquantitative MET uptake ratio in patients with malignant glioma. The study population comprised 40 patients with malignant glioma. Pretreatment magnetic resonance imaging (MRI) and MET-PET imaging were performed before the initiation of glioma treatment in all patients. The pretreatment MET uptake ratios and volumes were assessed. To create prognostically homogeneous subgroups, patients' pretreatment prognostic factors were stratified according to the six classes of Radiation Therapy Oncology Group recursive partitioning analysis (RTOG RPA). Univariate and multivariate analyses were performed to determine significant prognostic factors. Survival analyses identified the pretreatment volume of MET uptake and a higher RTOG RPA class as significant predictors. In contrast, pretreatment maximum areas of contrast enhancement on MRI and semiquantitative MET uptake ratios could not be identified as significant prognostic factors. The patients' outcomes and Karnofsky Performance Scale scores were significantly correlated with pretreatment volume of MET uptake but not with semiquantitative MET uptake ratio. The data suggest that pretreatment volumetry of MET uptake but not the semiquantitative MET uptake ratio is a useful biologic prognostic marker in patients with malignant glioma.

Purpose: In recent years there has been an increase in the development of radioligands targeting the 18-kDa translocator protein (TSPO). TSPO expression is well documented in activated microglia and serves as a biomarker for imaging neuroinflammation. In addition, TSPO has also been reported to be overexpressed in a number of cancer cell lines and human tumours including glioma. Here we investigated the use of [(18)F]DPA-714, a new TSPO positron emission tomography (PET) radioligand to image glioma in vivo., Methods: We studied the uptake of [(18)F]DPA-714 in three different rat strains implanted with 9L rat glioma cells: Fischer (F), Wistar (W) and Sprague Dawley (SD) rats. Dynamic [(18)F]DPA-714 PET imaging, kinetic modelling of PET data and in vivo displacement studies using unlabelled DPA-714 and PK11195 were performed. Validation of TSPO expression in 9L glioma cell lines and intracranial 9L gliomas were investigated using Western blotting and immunohistochemistry of brain tissue sections., Results: All rats showed significant [(18)F]DPA-714 PET accumulation at the site of 9L tumour implantation compared to the contralateral brain hemisphere with a difference in uptake among the three strains (F > W > SD). The radiotracer showed high specificity for TSPO as demonstrated by the significant reduction of [(18)F]DPA-714 binding in the tumour after administration of unlabelled DPA-714 or PK11195. TSPO expression was confirmed by Western blotting in 9L cells in vitro and by immunohistochemistry ex vivo., Conclusion: The TSPO radioligand [(18)F]DPA-714 can be used for PET imaging of intracranial 9L glioma in different rat strains. This preclinical study demonstrates the feasibility of employing [(18)F]DPA-714 as an alternative radiotracer to image human glioma.

In patients with World Health Organization (WHO) grade III glioma with a lack of or minimal (< 1 cm3) magnetic resonance imaging (MRI) contrast enhancement, the volume of the metabolically active part of the tumor was assessed by [¹¹C]-methionine positron emission tomography (MET-PET). Eleven patients with WHO grade III gliomas underwent MET-PET and MRI (contrast-enhanced T1- and T2-weighted images). To calculate the volumes in cubic centimeters, threshold-based volume of interest analyses of the metabolically active tumor (MET uptake index ≥ 1.3), contrast enhancement, and the T2 lesion were performed after coregistration of all images. In all patients, the metabolically active tumor volume was larger than the volume of gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) enhancement (20.8 ± 18.8 vs 0.29 ± 0.25 cm3; p < .001). With the exception of one patient, the volumes of contrast enhancement were located within the metabolically active tumor volume. In contrast, in the majority of patients, MET uptake overlapped with the T2 lesion and reached beyond it (in 10 of 12 MRIs/MET-PET scans). The present data suggest that in patients with WHO grade III glioma with minimal or a lack of contrast enhancement, MET-PET delineates metabolically active tumor tissue. These findings support the use of combined PET-MRI with radiolabeled amino acids (eg, MET) for the delineating of the true extent of active tumor in the diagnosis and treatment planning of patients with gliomas.

Systemic cancer is the second most common cause of death in developed countries and metastatic brain tumour the most common tumour of the central nervous system (CNS). As the incidence of brain metastases appears to be rising, more accurate non-invasive imaging modalities for diagnosis, prognosis, prediction and follow-up of treatment are requisites for efficient patient management. Positron emission tomography (PET) imaging has the ability to evaluate different aspects of tumour microenvironment on the molecular and cellular level and impact the workup of patients with brain metastasis. This article reviews the current application of PET imaging in patients with metastatic brain disease.

Only a few Methyl-[11C]-L-methionine (MET) positron emission tomography (PET) studies have focused on children and young adults with brain neoplasm. Due to radiation exposure, long scan acquisition time, and the need for sedation in young children MET-PET studies should be restricted to this group of patients when a decision for further therapy is not possible from routine diagnostic procedures alone, e.g., structural imaging. We investigated the diagnostic accuracy of MET-PET for the differentiation between tumorous and non-tumorous lesions in this group of patients. Forty eight MET-PET scans from 39 patients aged from 2 to 21 years (mean 15 +/- 5.0 years) were analyzed. The MET tumor-uptake relative to a corresponding control region was calculated. A receiver operating characteristic (ROC) was performed to determine the MET-uptake value that best distinguishes tumorous from non-tumorous brain lesions. A differentiation between tumorous (n = 39) and non-tumorous brain lesions (n = 9) was possible at a threshold of 1.48 of relative MET-uptake with a sensitivity of 83% and a specificity of 92%, respectively. A differentiation between high grade malignant lesions (mean MET-uptake = 2.00 +/- 0.46) and low grade tumors (mean MET-uptake = 1.84 +/- 0.31) was not possible. There was a significant difference in MET-uptake between the histologically homogeneous subgroups of astrocytoma WHO grade II and anaplastic astrocytoma WHO grade III (P = 0.02). MET-PET might be a useful tool to differentiate tumorous from non-tumorous lesions in children and young adults when a decision for further therapy is difficult or impossible from routine structural imaging procedures alone.

Purpose: We investigated the relationship between three-dimensional volumetric data of the metabolically active tumour volume assessed using [(11)C]-methionine positron emission tomography (MET-PET) and the area of gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) enhancement assessed using magnetic resonance imaging (MRI) in patients with recurrent glioblastoma (GBM)., Material and Methods: MET-PET and contrast-enhanced MRI with Gd-DTPA were performed in 12 uniformly pretreated patients with recurrent GBM. To calculate the volumes in cubic centimetres, a threshold-based volume-of-interest (VOI) analysis of the metabolically active tumour volume (MET uptake indexes of > or = 1.3 and > or = 1.5) and of the area of Gd-DTPA enhancement was performed after coregistration of all images., Results: In all patients, the metabolically active tumour volume as shown using a MET uptake index of > or = 1.3 was larger than the volume of Gd-DTPA enhancement (30.2 + or - 22.4 vs. 13.7 + or - 10.6 cm(3); p = 0.04). Metabolically active tumour volumes as shown using MET uptake indexes of > or =1.3 and > or = 1.5 and the volumes of Gd-DTPA enhancement showed a positive correlation (r = 0.76, p = 0.003, for an index of > or =1.3, and r = 0.74, p = 0.005, for an index of > or =1.5)., Conclusion: The present data suggest that in patients with recurrent GBM the metabolically active tumour volume may be substantially underestimated by Gd-DTPA enhancement. The findings support the notion that complementary information derived from MET uptake and Gd-DTPA enhancement may be helpful in developing individualized, patient-tailored therapy strategies in patients with recurrent GBM.

Purpose: Compartmental modelling of 3′-deoxy-3′-[18F]-fluorothymidine (18F-FLT) PET-derived kinetics provides a method for noninvasive assessment of the proliferation rate of gliomas. Such analyses, however, require an input function generally derived by serial blood sampling and counting. In the current study, 18F-FLT kinetic parameters obtained from image-derived input functions were compared with those from input functions derived from arterialized blood samples., Methods: Based on the analysis of 11 patients with glioma (WHO grade II-IV) a procedure for the automated extraction of an input function from 18F-FLT brain PET data was derived. The time-activity curve of the volume of interest with the maximum difference in 18F-FLT uptake during the first 5 min after injection and the period from 60 to 90 min was corrected for partial-volume effects and in vivo metabolism of 18F-FLT. For each patient a two-compartment kinetic model was applied to the tumour tissue using the image-derived input function. The resulting kinetic rate constants K1 (transport across the blood-brain barrier) and Ki (metabolic rate constant or net influx constant) were compared with those obtained from the same data using the input function derived from blood samples. Additionally, the metabolic rate constant was correlated with the frequency of tumour cells stained with Ki-67, a widely used immunohistochemical marker of cell proliferation., Results: The rate constants from kinetic modelling were comparable when the blood sample-derived input functions were replaced by the image-derived functions (K1,img and K1,sample, r = 0.95, p < 10(-5); Ki,img and Ki,sample, r = 0.86, p < 0.001). A paired t-test showed no significant differences in the parameters derived with the two methods (K1,img and K1,sample, p = 0.20; Ki,img and Ki,sample, p = 0.92). Furthermore, a significant correlation between Ki,img and the percentage of Ki-67-positive cells was observed (r = 0.73, p = 0.01)., Conclusion: Kinetic modelling of 18F-FLT brain PET data using image-derived input functions extracted from human brain PET data with the practical procedure described here provides information about the proliferative activity of brain tumours which might have clinical relevance especially for monitoring of therapy response in future clinical trials.

Objectives: To improve patients health-related quality of life (HQL) after transient ischemic attack (TIA) or ischemic stroke; to guarantee an effective secondary prevention; to increase the patient's satisfaction with recommendations regarding their medication by pharmacists., Setting: Stroke Unit, neurological ward at the Klinikum Fulda, rehabilitation hospitals and community-based pharmacies in the region of Fulda, Germany., Method: Patients with TIA or ischemic stroke were included. The patients were assigned to an intervention group (IG) or a control group (CG). The individual assignment of patients to IG or CG was based on the type of the local pharmacy to which patients belong. Community-based pharmacies either delivered standard care (CG) or provided additional intensified pharmaceutical care (PC; IG). Pharmacies delivering PC belong to a pre-existing "Quality Assurance Working Group" (QAWG). To evaluate the patient's HQL, the Short Form-36 (SF-36) was used at study entry in hospital and at 12 months. The secondary prevention was documented at study entry in hospital and at 12 months. The patients' satisfaction was measured by a questionnaire at the end of the study., Main Outcome Measures: Patients' HQL; secondary prevention; patients' satisfaction with recommendations of the pharmacists with regards to their medication., Results: Out of 1316 patients screened for participation in this study, 255 were recruited with 90/255 patients assigned to the IG and 165/255 patients assigned to the CG. During the study, the HQL of the patients in the IG did not change significantly. A significant decrease in the HQL was observed for the CG in 7/8 subscales and in both summary measures of the SF-36. After 12 months, 85.3% of the patients in the IG and 86.3% of the patients in the CG were treated with antiplatelet drugs or oral anticoagulants in accordance to treatment guidelines. Patients in the IG were significantly more satisfied with the individualized recommendations of the pharmacists than patients in the CG., Conclusion: Our findings indicate that an intensified PC of patients after ischemic stroke by dedicated pharmacists may have a positive impact on HQL and patients' satisfaction. PC in this study had no impact on adherence to secondary prevention medication.

A 61-year-old patient with a sudden numbness of the right arm and hand and signs of amnestic aphasia is admitted to the stroke unit with the diagnosis of an acute ischemic stroke for systemic thrombolysis. Based on a case-report, drug-related problems are discussed according to the SOAP scheme. Aspects of pharmaceutical care such as counselling by a pharmacist about secondary prevention, discharge information and a pharmaceutical care plan in the community pharmacy are described.

Gene therapy of patients with glioblastoma using viral and non-viral vectors, which are applied by direct injection or convection-enhanced delivery (CED), appear to be satisfactorily safe. Up to date, only single patients show a significant therapeutic benefit as deduced from single long-term survivors. Non-invasive imaging by PET for the identification of viable target tissue and for assessment of transduction efficiency shall help to identify patients which might benefit from gene therapy, while non-invasive follow-up on treatment responses allows early and dynamic adaptations of treatment options. Therefore, molecular imaging has a critical impact on the development of standardised gene therapy protocols and on efficient and safe vector applications in humans.

Introduction: Magnetic resonance tomography (MRT) is the investigation of choice for diagnosing cerebral glioma, but its capacity to differentiate tumor tissue from non-specific tissue changes is limited. Positron emission tomography (PET) and single photon emission computerized tomography (SPECT) using radiolabeled amino acids add information which helps increase diagnostic accuracy., Methods: Review based on the authors' own research results and a selective literature review., Results: The use of radiolabeled amino acids allows better delineation of tumor margins and improves targeting of biopsy and radiotherapy, and planning surgery. In addition, amino acid imaging appears useful in distinguishing tumor recurrence from non-specific post-therapeutic scar tissue, in predicting prognosis in low grade gliomas, and in monitoring metabolic response during treatment., Discussion: The benefits of amino acid imaging in cerebral gliomas support arguments for its introduction into routine clinical practice in defined clinical situations; however, its influence on treatment quality remains to be demonstrated.

Background: Wound infections due to Clostridium botulinum in Germany are rare and occur predominantly in heroin injectors, especially after subcutaneous or intramuscular injection of heroin ("skin popping"), which is contaminated with spores of C. botulinum. We report a rapid geographical clustering of cases in Germany in a region between Cologne, Bonn, and Aachen with wound botulism and consecutive systemic C. botulinum intoxication in intravenous drug users (IDUs) within 6 weeks in October and November 2005., Patients: A group of 12 IDUs with wound botulism after "skin popping.", Results: Clinical data were available in 11 (92%) of 12 patients; in 7 (58%) of the 12 cases, there was cranial nerve involvement including mydriasis, diplopia, dysarthria, and dysphagia, followed by progressing symmetric and flaccid paralysis of proximal muscles of the neck, arms, trunk, and respiratory muscles. Mechanical respiratory support was necessary. Five of the IDUs were treated with antitoxin, but mechanical respiratory support could not be avoided. The mean ventilation duration was 27.4 days (range 6-77 days). In 4 patients (33%), mechanical ventilation could be avoided; two were treated with antitoxin., Conclusions: This report describes rapid geographical clustering of wound botulism with severe respiratory complications in IDUs after "skin popping," which has not previously been reported either in Germany or any other European country. Based on these observations and those in other European countries, we conclude that there is a trend towards "skin popping," suggesting a change in injection practices in IDUs. Secondly, we conclude that the total number of cases with wound botulism is likely to increase because "skin popping" is the main risk factor.

The peroxisome proliferator-activated receptor gamma (PPARgamma), a member of the nuclear hormone receptor family, represents a possible new target in glioma therapy. Because PPARgamma plays a crucial role in regulation of insulin sensitivity, synthetic agonists are already in clinical use for type II diabetes treatment. Beyond these metabolic effects, PPARgamma agonists exhibit antineoplastic effects. In this study, we investigated the antineoplastic effects of the PPARgamma agonist pioglitazone in glioma cells. Pioglitazone reduced cellular viability of rat, human, and PPARgamma-overexpressing glioma cells in vitro in a time- and concentration-dependent manner. No antineoplastic effects were induced by pioglitazone in glioma cells overexpressing a PPARgamma mutant. Furthermore, proliferation was reduced by pioglitazone, as measured by Ki-67 immunoreactivity, in vitro. Continuous intracerebral infusion of pioglitazone into gliomas induced by intrastriatal injection of C6 cells reduced tumor volumes by 83%. Oral administration of pioglitazone reduced tumor volumes by 76.9%. Subsequent brain tissue analysis revealed induction of apoptotic cell death. Ki-67 expression and BrdU incorporation revealed a reduction of proliferation in vivo. Reduced invasion of C6 cells and lower matrix metalloproteinase 9 levels in vivo indicate pioglitazone-mediated reduction of invasion. Together, these data indicate that pioglitazone may be of potential use in treatment of malignant gliomas.

Purpose: The purpose of this study was to monitor the metabolic effects of temozolomide (TMZ) chemotherapy in malignant gliomas by means of repeated positron emission tomography (PET) with [(11)C]methionine (MET)., Methods: Fifteen patients with histologically proven malignant glioma were treated by TMZ chemotherapy. MET-PET studies were performed before and after the third cycle of TMZ chemotherapy in all patients, and in 12 patients also after the sixth cycle. Gadolinium-enhanced MRI studies were performed in 12 patients before the first and after the sixth cycle. Clinical status was assessed by the modified Rankin scale. Long-term outcome was assessed by calculating the time to progression (TTP) in months., Results: Decline in MET uptake during therapy corresponded to a stable clinical status. The median TTP was significantly longer in patients with decline in MET uptake than in those with increasing MET uptake (23 vs 3.5 months; p=0.01, log rank test). There was no significant correlation between change in MET uptake and change in contrast enhancement during treatment for all patients., Conclusion: The present data demonstrate that clinical stability, which is often achieved under TMZ chemotherapy of malignant glioma, corresponds to a decline in or stability of tumour amino acid metabolism. Tumour responses can already be demonstrated with MET-PET after three cycles of chemotherapy, and absence of progression at that time indicates a high probability of further stability during the next three cycles. A reduction in MET uptake during TMZ treatment predicts a favourable clinical outcome. Molecular imaging of amino acid uptake by MET-PET offers a new method of measurement of the biological activity of recurrent glioma.

Unlabelled: Because of the high glucose metabolism in normal brain tissue 18F-FDG is not the ideal tracer for the detection of gliomas. Methyl-11C-l-methionine (11C-MET) is better suited for imaging the extent of gliomas, because it is transported specifically into tumors but only insignificantly into normal brain. 3'-Deoxy-3'-18F-fluorothymidine (18F-FLT) has been introduced as a proliferation marker in a variety of neoplasias and has promising potential for the detection of brain tumors, because its uptake in normal brain is low. Additionally, the longer half-life might permit differentiation between transport and intracellular phosphorylation., Methods: PET of 18F-FLT and 11C-MET was performed on 23 patients (age range, 20-70 y) with histologically verified gliomas of different grades. On all patients, conventional MRI was performed, and 16 patients additionally underwent contrast-enhanced imaging. Images were coregistered, and the volumes of abnormality were defined for PET and MRI. Uptake ratios and standardized uptake values (SUVs) of various tumors and regions were assessed by region-of-interest analysis. Kinetic modeling was performed on 14 patients for regional time-activity curves of 18F-FLT from tumorous and normal brain tissue., Results: Sensitivity for the detection of tumors was lower for 18F-FLT than for 11C-MET (78.3% vs. 91.3%), especially for low-grade astrocytomas. Tumor volumes detected by 18F-FLT and 11C-MET were larger than tumor regions displaying gadolinium enhancement (P<0.01). Uptake ratios of 18F-FLT were higher than uptake ratios of 11C-MET (P<0.01). Uptake ratios of 18F-FLT were higher in glioblastomas than in astrocytomas (P<0.01). Absolute radiotracer uptake of 18F-FLT was low and significantly lower than that of 11C-MET (SUV, 1.3+/-0.7 vs. 3.1+/-1.0; P<0.01). Some tumor regions were detected only by either 18F-FLT (7 patients) or 11C-MET (13 patients). Kinetic modeling revealed that 18F-FLT uptake in tumor tissue seems to be predominantly due to elevated transport and net influx. However, a moderate correlation was found between uptake ratio and phosphorylation rate k3 (r=0.65 and P=0.01 for grade II-IV gliomas; r=0.76 and P<0.01 for grade III-IV tumors)., Conclusion: 18F-FLT is a promising tracer for the detection and characterization of primary central nervous system tumors and might help to differentiate between low- and high-grade gliomas. 18F-FLT uptake is mainly due to increased transport, but irreversible incorporation by phosphorylation might also contribute. In some tumors and tumor areas, 18F-FLT uptake is not related to 11C-MET uptake. In view of the high sensitivity and specificity of 11C-MET PET for imaging of gliomas, it cannot be excluded that 18F-FLT PET was false positive in these areas. However, the discrepancies observed for the various imaging modalities (18F-FLT and 11C-MET PET as well as gadolinium-enhanced MRI) yield complementary information on the activity and the extent of gliomas and might improve early evaluation of treatment effects, especially in patients with high-grade gliomas. Further studies are needed, including coregistered histology and kinetic analysis in patients undergoing chemotherapy.