Project description:While hyperthermia has been shown to be an effective adjuvant anti-tumor treatment to radiotherapy, we still do not completely understand effects thermoradiotherapy on tumor phenotype or how these effects vary among different tumors. Here, we performed gene expression analysis in 22 spontaneous canine sarcomas before and after the first hyperthermia treatment that was administered as an adjuvant to radiotherapy. Diffusion weighted MRI (DWI) was done prior to the treatment course and at the end of therapy. Using supervised analysis, we identified significant correlation of DWI with several genes involved in VEGF signaling, telomerase, Wnt pathways and fatty acid synthesis. When the change of gene expression caused by treatment was examined, we found that thermoradiotherapy led to the induction of well known cycle regulators p21 and mdm2 and reduced cellular proliferation in most treated tumors. We also identified two tumor subtypes with dramatic differences in the gene expression response and treatment response at the end of therapy. In the subtype with strong expression and increase in DWI, the mRNA level of hsp70, POT1 and centrosomal proteins was significantly higher. In the other subtype with modest response to hyperthermia, levels of CD31, vWF and transferrin was noted to be significantly higher. It is also possible to build a predictive model based on the pre-treatment gene expression to predict the likely treatment response of the tumors. The differential expression between the two tumor subtypes was used to interrogate connectivity map and identify linkages to an HDAC inhibitor and geldanamycin, an HSP90 inhibitor. Both HDAC inhibitors and hsp90 inhibitor geldanamycin are shown to synergerize with thermoradiotherapy in reducing cell survival in clonogenic assays. Taken together, the gene expression studies of hyperthermia-treated spontaneous canine tumors shed mechanistic insights into the heterogeneity of thermoradiotherapy response and identified pathway-targeting compounds with synergistic potential to enhance its therapeutic benefits. To our knowledge, this is one of the first successful attempts to link genomic and functional imaging changes together. This is the first demonstration of using such associations to understand the connection between cellular and physiologic responses to treatment. gene expression analysis in 22 spontaneous canine sarcomas before and after the first hyperthermia treatment that was administered as an adjuvant to radiotherapy.

Project description:The aim of the study is to assess the value of whole body diffusion weighted MR imaging (WB-DWI) as a non-invasive method. On one hand for pretreatment lesion detection and post-therapeutic tumor recurrence but also for early therapy monitoring with the intention to early identify patients with a poor tumor response. Our research group demonstrated that this technique is accurate in patients with head and neck cancer it could differentiate between viable tumor tissue and inflammatory or necrotic tissue at variable time points after completion of radiotherapy. In the literature it is stated that DWI can also predict the response to chemotherapeutic therapy. This is only true for focal MRI images (eg only in liver). This study aims to determine whether the whole body technique can efficiently be used because the distribution of metastases is systemic. The study includes two phases: In a first phase, a baseline study will be conducted; all possible injury types will be gathered to determine the variability in signal characteristics to finally determine appropriate thresholds to differentiate between benign and malignant lesions. This should allow us later on to perform prospective studies. In a second phase, different applications such as: * pretherapeutic staging * Detection of post-therapy recurrence * Early evaluation of systemic cytotoxic therapy. The results of the DW-MRI will be compared with those of PET, CT and conventional MRI which are now routinely performed for the diagnosis of colorectal tumors. The scans will be performed in a group of patients on a 3 Tesla MR system. This system is fully approved by the European and American standards and the patients will not be exposed to radiation or contrast agents. In principle, all patients treated for gastrointestinal cancer were included after informed consent from the patient. This study is important to investigate whether DWI is accurate in the pre-therapeutic injury detection and staging of gastrointestinal tumors compared with PET / CT and DWI. In addition it is important to predict the outcome after therapy.

Project description:While hyperthermia has been shown to be an effective adjuvant anti-tumor treatment to radiotherapy, we still do not completely understand effects thermoradiotherapy on tumor phenotype or how these effects vary among different tumors. Here, we performed gene expression analysis in 22 spontaneous canine sarcomas before and after the first hyperthermia treatment that was administered as an adjuvant to radiotherapy. Diffusion weighted MRI (DWI) was done prior to the treatment course and at the end of therapy. Using supervised analysis, we identified significant correlation of DWI with several genes involved in VEGF signaling, telomerase, Wnt pathways and fatty acid synthesis. When the change of gene expression caused by treatment was examined, we found that thermoradiotherapy led to the induction of well known cycle regulators p21 and mdm2 and reduced cellular proliferation in most treated tumors. We also identified two tumor subtypes with dramatic differences in the gene expression response and treatment response at the end of therapy. In the subtype with strong expression and increase in DWI, the mRNA level of hsp70, POT1 and centrosomal proteins was significantly higher. In the other subtype with modest response to hyperthermia, levels of CD31, vWF and transferrin was noted to be significantly higher. It is also possible to build a predictive model based on the pre-treatment gene expression to predict the likely treatment response of the tumors. The differential expression between the two tumor subtypes was used to interrogate connectivity map and identify linkages to an HDAC inhibitor and geldanamycin, an HSP90 inhibitor. Both HDAC inhibitors and hsp90 inhibitor geldanamycin are shown to synergerize with thermoradiotherapy in reducing cell survival in clonogenic assays. Taken together, the gene expression studies of hyperthermia-treated spontaneous canine tumors shed mechanistic insights into the heterogeneity of thermoradiotherapy response and identified pathway-targeting compounds with synergistic potential to enhance its therapeutic benefits. To our knowledge, this is one of the first successful attempts to link genomic and functional imaging changes together. This is the first demonstration of using such associations to understand the connection between cellular and physiologic responses to treatment.

Project description:Background:To evaluate the association of multiparametric and multiregional MRI-features with key molecular characteristics in patients with newly-diagnosed glioblastoma. Methods:Retrospective data evaluation was approved by the local ethics committee of the University of Heidelberg (ethics approval number: S-320/2012) and informed consent was waived. Preoperative MRI-features were correlated with key molecular characteristics within a single-institutional cohort of 152 patients with newly-diagnosed glioblastoma. Preoperative MRI-features (n=31) included multiparametric (anatomical, diffusion-, perfusion-, and susceptibility-weighted images) and multiregional (contrast enhancing and non-enhancing FLAIR-hyperintense) information with (histogram) quantification of tumor volumes, volume ratios, apparent diffusion coefficients, cerebral blood flow / volume (CBF / CBV) and intratumoral susceptibility signals. Molecular characteristics determined with the Illumina Infinium HumanMethylation450 array included global DNA-methylation subgroups (e.g. mesenchymal (MES), RTK I “PGFRA”, RTK II “classic”), MGMT-promoter methylation status and hallmark copy-number-variations (EGFR-, PDGFRA-, MDM4- and CDK4-amplification; PTEN-, CDKN2A-, NF1- and RB1-loss). Univariate analyses (voxel-lesion-symptom-mapping for tumor location, Wilcoxon-test for all other MRI-features) as well as machine-learning models were applied to study the strength of association and discriminative value of MRI-features for predicting underlying molecular characteristics. Results: There was no tumor location predilection for any of the assessed molecular parameters (permutation-adjusted p>0.05 each). Univariate imaging parameter associations were noted for EGFR amplification and CDKN2A loss, both demonstrating increased nrCBV and nrCBF values (performance of these parameters, as assessed by the area under the ROC curve ranged from 63 to 69%, FDR-adjusted p<0.05, respectively). Subjecting all MRI-features to machine-learning-based classification allowed to predict EGFR amplification status and the RTK II “classic” GB subgroup with a moderate, yet significantly greater accuracy (63% for EGFR [p<0.01] and 61% for RTK II [p=0.01]) than the prediction by chance, whereas prediction accuracy for all other molecular parameters was non-significant (p>0.05, all models). Conclusions: In summary, we found univariate associations between established MRI-features and molecular characteristics, however not of sufficient strength to allow the generation of machine-learning classification models for reliable and clinically meaningful prediction of the assessed molecular characteristics in patients with newly-diagnosed glioblastoma.

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The Value of Diffusion-weighted Imaging in Evaluating the Early Efficacy of Liver Metastasis in Colorectal Cancer

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