Opioid burden in patients with inoperable pancreatic adenocarcinoma and the development of a multivariable risk prediction model for opioid use: A retrospective cohort study.

INTRODUCTION: Risk prediction models to guide patient selection for early pre-emptive endoscopic ultrasound guided coeliac plexus neurolysis are lacking. This study aimed to determine in patients with inoperable pancreatic cancer: (1) opioid burden, (2) the relationship between opioid use and all-cause mortality, (3) risk factors for opioid use, and (4) develop and internally validate a risk prediction model for opioid use at three months. METHODS: This was a single-centre retrospective cohort study of patients with confirmed pancreatic cancer. Cox proportional hazard regression estimated the association between opioid use at baseline and all-cause mortality. Logistic regression estimated the associations between clinical and radiological variables with opioid use by three months. Two risk prediction models were developed for opioid use (clinical and clinical-radiological). Model discrimination and calibration was assessed. RESULTS: In total, 383 patients with inoperable pancreatic cancer were included. Prevalence of pain ranged between 37% and 47% at three monthly intervals in the first year of diagnosis. Opioid use at baseline was associated with poorer survival. Age, pain at presentation, performance status, tumour distance from the right ganglion, the anterior-posterior and the latero-lateral tumour dimensions were independent risk factors for the opioid use at three months. The Area Under Curve (AUC) for the clinical and clinical-radiological models was 0.81 and 0.84, respectively. Models were well calibrated. CONCLUSIONS: Opioid use is prevalent in patients with pancreatic cancer, associated with poor prognosis, and can be predicted based on clinical and radiological variables. External validation of this predictive model is required.

A novel method for measuring bowel motility and velocity with dynamic magnetic resonance imaging in two and three dimensions.

Increasingly, dynamic magnetic resonance imaging (MRI) has potential as a noninvasive and accessible tool for diagnosing and monitoring gastrointestinal motility in healthy and diseased bowel. However, current MRI methods of measuring bowel motility have limitations: requiring bowel preparation or long acquisition times; providing mainly surrogate measures of motion; and estimating bowel-wall movement in just two dimensions. In this proof-of-concept study we apply a method that provides a quantitative measure of motion within the bowel, in both two and three dimensions, using existing, vendor-implemented MRI pulse sequences with minimal bowel preparation. This method uses a minimised cost function to fit linear vectors in the spatial and temporal domains. It is sensitised to the spatial scale of the bowel and aims to address issues relating to the low signal-to-noise in high-temporal resolution dynamic MRI scans, previously compensated for by performing thick-slice (10-mm) two-dimensional (2D) coronal scans. We applied both 2D and three-dimensional (3D) scanning protocols in two healthy volunteers. For 2D scanning, analysis yielded bi-modal velocity peaks, with a mean antegrade motion of 5.5 mm/s and an additional peak at ~9 mm/s corresponding to longitudinal peristalsis, as supported by intraoperative data from the literature. Furthermore, 3D scans indicated a mean forward motion of 4.7 mm/s, and degrees of antegrade and retrograde motion were also established. These measures show promise for the noninvasive assessment of bowel motility, and have the potential to be tuned to particular regions of interest and behaviours within the bowel.

A non-invasive approach to monitor chronic lymphocytic leukemia engraftment in a xenograft mouse model using ultra-small superparamagnetic iron oxide-magnetic resonance imaging (USPIO-MRI).

Chronic lymphocytic leukemia (CLL) is the most prevalent leukemia among adults. Despite its indolent nature, CLL remains an incurable disease. Herein we aimed to monitor CLL disease engraftment and, progression/regression in a xenograft CLL mouse model using ultra-small superparamagnetic iron oxide-magnetic resonance imaging (USPIO-MRI). Spleen contrast enhancement, quantified as percentage change in signal intensity upon USPIO administration, demonstrated a difference due to a reduced USPIO uptake, in the spleens of mice injected with CLL cells (NSG-CLL, n=71) compared to controls (NSG-CTR, n=17). These differences were statistically significant both after 2 and 4weeks from CLL cells injection. In addition comparison of mice treated with rituximab with untreated controls for changes in spleen iron uptake confirmed that it is possible to monitor treatment efficacy in this mouse model of CLL using USPIO-enhanced MRI. Further applications could include the preclinical in vivo monitoring of new therapies and the clinical evaluation of CLL patients.

Pharmacokinetics, pharmacodynamics and efficacy on pediatric tumors of the glioma radiosensitizer KU60019.

We have recently reported that glioblastoma (GB)-initiating cells (GIC) with low expression and/or mutation of TP53 and high expression of PI3K ("responder" genetic profile) can be effectively and safely radiosensitized by the ATM inhibitor KU60019. We report here on drug's diffusion and elimination from the animal body and brain, its effects on orthotopic GB and efficacy toward pediatric GIC. Healthy mice were infused by convection enhanced delivery (CED) with KU60019 and the drug kinetics followed by high performance liquid chromatography-mass spectrometry. Already at the end of CED, KU60019 had diffused from the injection site to the ipsilateral and, to a lower extent, controlateral hemisphere. After 24 hr, no drug could be detected all over the brain or in other organs, indicating rapid draining and excretion. After intraperitoneal injection, traces only of KU60019 could be detected in the brain, indicating inability to cross the brain-blood barrier. Consistent with the induction of cell cycle progression previously observed in vitro, KU60019 stimulated proliferation of orthotopic GB cells with the highest effect observed 96 hr after drug delivery. Adult GIC with high expression of TP53 and low expression of PI3K could be radiosensitized by KU60019, although less promptly than GIC bearing the "responder" profile. Consistent with the kinetics of proliferation induction, the highest radiosensitizing effect was observed 96 hr after delivery of KU60019 to GIC. Pediatric GIC could be similarly radiosensitized after exposure to KU60019. The results indicate that ATM inhibition may allow to radiosensitize a wide range of adult and pediatric high-grade gliomas.

MEMRI and tumors: a method for the evaluation of the contribution of Mn(II) ions in the extracellular compartment.

The purpose of the work was to set-up a simple method to evaluate the contribution of Mn(2+) ions in the intra- and extracellular tumor compartments in a MEMRI experiment. This task has been tackled by "silencing" the relaxation enhancement arising from Mn(2+) ions in the extracellular space. In vitro relaxometric measurements allowed assessment of the sequestering activity of DO2A (1,4,7,10-tetraazacyclododecane-1,7-diacetic acid) towards Mn(2+) ions, as the addition of Ca-DO2A to a solution of MnCl2 causes a drop of relaxivity upon the formation of the highly stable and low-relaxivity Mn-DO2A. It has been proved that the sequestering ability of DO2A towards Mn(2+) ions is also fully effective in the presence of serum albumin. Moreover, it has been shown that Mn-DO2A does not enter cell membranes, nor does the presence of Ca-DO2A in the extracellular space prompt migration of Mn ions from the intracellular compartment. On this basis the in vivo, instantaneous, drop in SE% (percent signal enhancement) in T1 -weighted images is taken as evidence of the sequestration of extracellular Mn(2+) ions upon addition of Ca-DO2A. By applying the method to B16F10 tumor bearing mice, T1 decrease is readily detected in the tumor region, whereas a negligible change in SE% is observed in kidneys, liver and muscle. The relaxometric MRI results have been validated by ICP-MS measurements.

Predictability, efficacy and safety of radiosensitization of glioblastoma-initiating cells by the ATM inhibitor KU-60019.

We have previously shown that pharmacological inhibition of ataxia telangiectasia mutated (ATM) protein sensitizes glioblastoma-initiating cells (GICs) to ionizing radiation (IR). Herein, we report the experimental conditions to overcome GIC radioresistance in vitro using the specific ATM inhibitor KU-60019, two major determinants of the tumor response to this drug and the absence of toxicity of this treatment in vitro and in vivo. Repeated treatments with KU-60019 followed by IR substantially delayed GIC proliferation in vitro and even eradicated radioresistant cells, whereas GIC treated with vehicle plus radiation recovered early and expanded. The tumor response to the drug occurred under a cutoff level of expression of TP53 and over a cutoff level of expression of phosphatidylinositol 3-kinase (PI3K). No increased clastogenicity or point mutagenicity was induced by KU-60019 plus radiation when compared to vehicle plus radiation. No significant histological changes to the brain or other organs were observed after prolonged infusion into the brain of KU-60019 at millimolar concentrations. Taken together, these findings suggest that GIC-driven tumors with low expression of TP53 and high expression of PI3K might be effectively and safely radiosensitized by KU-60019.

In vivo imaging of human breast cancer mouse model with high level expression of calcium sensing receptor at 3T.

OBJECTIVES: To demonstrate that manganese can visualise calcium sensing receptor (CaSR)-expressing cells in a human breast cancer murine model, as assessed by clinical 3T magnetic resonance (MR). METHODS: Human MDA-MB-231-Luc or MCF7-Luc breast cancer cells were orthotopically grown in NOD/SCID mice to a minimum mass of 5 mm. Mice were evaluated on T1-weighted sequences before and after intravenous injection of MnCl(2). To block the CaSR-activated Ca(2+) channels, verapamil was injected at the tumour site 5 min before Mn(2+) administration. CaSR expression in vivo was studied by immunohistochemistry. RESULTS: Contrast enhancement was observed at the tumour periphery 10 min after Mn(2+) administration, and further increased up to 40 min. In verapamil-treated mice, no contrast enhancement was observed. CaSR was strongly expressed at the tumour periphery. CONCLUSION: Manganese enhanced magnetic resonance imaging can visualise CaSR-expressing breast cancer cells in vivo, opening up possibilities for a new MR contrast agent. KEY POINTS: • Manganese contrast agents helped demonstrate breast cancer cells in an animal model. • Enhancement was most marked in cells with high calcium sensing receptor expression. • Manganese uptake was related to the distribution of CaSR within the tumour. • Manganese MRI may become useful to investigate human breast cancer.

Clinically significant findings in patients with focal incidental colorectal abnormalities on positron emission tomography-CT scans.

INTRODUCTION: The aim of this study was to determine the clinical significance of focal incidentally detected colorectal abnormalities on 18 F- Fluoro-2-Deoxy-D-Glucose (FDG) PET-CT scans. METHODS: Retrospective audit of PET-CT scans performed at our institution between 2009 and 2014. Demographic and clinical details were retrieved from electronic patient records. An advanced adenoma was defined as: ≥1 cm in size, tubullo-villous histology, or displaying high grade dysplasia. A high-risk lesion (HRL) was defined as an advanced adenoma or colorectal cancer (CRC). RESULTS: Of the 1911 PET-CT eligible scans, focal incidental colorectal FDG uptake was detected in 99 (5.2%) patients. Colonoscopy was undertaken in 43 (43.4%) patients and 45 FDG-avid sites were evaluated. The commonest site of abnormal FDG uptake was the rectosigmoid region, with 34 (75.6%) of the 45 foci being located in this area. Overall, 23 (53.5%) of these patients had clinically significant pathology. Of the 45 focal PET-CT abnormalities evaluated, 17 (37.8%) were adenomas, of which 11 (24.4%) were advanced adenomas, and six (13.3%) were cancers, with a total of 17 (37.8%) HRLs. Five of the six patients with CRC underwent surgical resection, whilst one had endoscopic resection. The overall survival for the entire cohort was 18 months (range 1-72 months) with those that underwent colonoscopy having higher overall survival compared to those that did not (38 vs. 13.5 months). CONCLUSION: Incidental colorectal abnormalities on PET-CT scans are often clinically significant. However, careful selection for colonoscopy is important due to the poor survival in these patients related to the underlying primary malignancy.

Brachial plexus MR imaging: accuracy and reproducibility of DTI-derived measurements and fibre tractography at 3.0-T.

OBJECTIVE: To estimate intrastudy, intraobserver and interobserver reproducibility of DTI-derived measurements and fibre tractography (FT) at 3.0 T MR imaging in subjects without known brachial plexus pathology. METHODS: IRB approval and written informed consent were obtained. Forty healthy volunteers underwent bilateral 3.0-T DTI of the brachial plexus. Postprocessing included FT and analysis of fractional anisotropy (FA) and apparent diffusion coefficient (ADC). Four authors performed postprocessing and analysis independently and in different sessions at baseline and after 4 weeks. Non-parametric tests and Bland-Altman statistics were used. RESULTS: Minimum and maximum percent variability were 6% and 20% for FA (85%-93% reproducibility). For ADC minimum and maximum percent variability were 6% and 18% (86%-97% reproducibility). Quality of fibre tract was rated equal in 80% and slightly different in 20% of subjects. Minimum detectable differences between limb were 37% for FA and 32% for ADC. Intra- and inter-observer agreement were good. Evaluating the combined influence of the observer and of the repeated measurements the reproducibility was 81-92%. CONCLUSION: DTI of brachial plexus nerves is reliable. The healthy contralateral side can be used as an internal control considering that changes in FA and ADC values of less that 37% and 32% will not be clinically detectable with confidence.

Manganese-enhanced MRI (MEMRI) in breast and prostate cancers: Preliminary results exploring the potential role of calcium receptors.

PROCEDURES: To preliminary assess the relationship between Manganese Enhanced Magnetic Resonance Imaging (MEMRI) and the expression of calcium receptors in human prostate and breast cancer animal models. METHODS: NOD/SCID mice were inoculated with MDA-MB-231 breast cancer cells and prostate PC3 cancer cells to develop orthotopic or pseudometastatic cancer animal models. Mice were studied on a clinical 3T scanner by using a prototype birdcage coil before and after intravenous injection of MnCl2. Assessment of receptor's status was carried out after the MR images acquisition by immunohistochemistry on excised tumours. RESULTS: Manganese contrast enhancement in breast or prostate cancer animal models well correlated with CaSR expression (p<0.01), whereas TRPV6 expression levels appeared not relevant to the Mn uptake. CONCLUSION: Our preliminary results suggest that MEMRI appears an efficient tool to characterize human breast and prostate cancer animal models in the presence of different expression level of calcium receptors.

Enhanced antitumor efficacy of clinical-grade vasculature-targeted liposomal doxorubicin.

PURPOSE: In vivo evaluation of good manufacturing practice-grade targeted liposomal doxorubicin (TVT-DOX), bound to a CD13 isoform expressed on the vasculature of solid tumors, in human tumor xenografts of neuroblastoma, ovarian cancer, and lung cancer. EXPERIMENTAL DESIGN: Mice were implanted with lung, ovarian, or neuroblastoma tumor cells via the pulmonary, peritoneal, or orthotopic (adrenal gland) routes, respectively, and treated, at different days post inoculation, with multiple doses of doxorubicin, administered either free or encapsulated in untargeted liposomes (Caelyx) or in TVT-DOX. The effect of TVT-DOX treatment on tumor cell proliferation, viability, apoptosis, and angiogenesis was studied by immunohistochemical analyses of neoplastic tissues and using the chick embryo chorioallantoic membrane assay. RESULTS: Compared with the three control groups (no doxorubicin, free doxorubicin, or Caelyx), statistically significant improvements in survival was seen in all three animal models following treatment with 5 mg/kg (maximum tolerated dose) of TVT-DOX, with long-term survivors occurring in the neuroblastoma group; increased survival was also seen at a dose of 1.7 mg/kg in mice bearing neuroblastoma or ovarian cancer. Minimal residual disease after surgical removal of neuroblastoma primary mass, and the enhanced response to TVT-DOX, was visualized and quantified by bioluminescence imaging and with magnetic resonance imaging. When treated with TVT-DOX, compared with Caelyx, all three tumor models, as assayed by immunohistochemistry and chorioallantoic membrane, showed statistically significant reductions in cell proliferation, blood vessel density, and microvessel area, showing increased cell apoptosis. CONCLUSION: TVT-DOX should be evaluated as a novel angiostatic strategy for adjuvant therapy of solid tumors.

MR and iron magnetic nanoparticles. Imaging opportunities in preclinical and translational research.

Ultrasmall superparamagnetic iron oxide nanoparticles and magnetic resonance imaging provide a non-invasive method to detect and label tumor cells. These nanoparticles exhibit unique properties of superparamagnetism and can be utilized as excellent probes for magnetic resonance imaging. Most work has been performed using a magnetic resonance scanner with high field strength up to 7 T. Ultrasmall superparamagnetic iron oxide nanoparticles may represent a suitable tool for labeling molecular probes that target specific tumor-associated markers for in vitro and in vivo detection by magnetic resonance imaging. In our study, we demonstrated that magnetic resonance imaging at 1.5 T allows the detection of ultrasmall superparamagnetic iron oxide nanoparticle conjugated antibody specifically bound to human tumor cells in vitro and in vivo, and that the magnetic resonance signal intensity correlates with the concentration of ultrasmall superparamagnetic iron oxide nanoparticle antibody used and with the antigen density at the cell surface. The experiments were performed using two different means of targeting: direct and indirect magnetic tumor targeting. The imaging of tumor antigens using immunospecific contrast agents is a rapidly evolving field, which can potentially aid in early disease detection, monitoring of treatment efficacy, and drug development. Cell labeling by iron oxide nanoparticles has emerged as a potentially powerful tool to monitor trafficking of a large number of cells in the cell therapy field. We also studied the labeling of natural killer cells with iron nanoparticles to a level that would allow the detection of their signal intensity with a clinical magnetic resonance scanner at 1.5 T. Magnetic resonance imaging and iron magnetic nanoparticles are able to increase the accuracy and the specificity of imaging and represent new imaging opportunities in preclinical and translational research.

Correlation between Choline Peak at MR Spectroscopy and Calcium-Sensing Receptor Expression Level in Breast Cancer: A Preliminary Clinical Study.

PURPOSE: The calcium-sensing receptor (CaSR) is overexpressed in many pathological states including breast cancer. Since choline kinase may be activated in breast cancer cells by CaSR resulting in increased phosphocholine production, we sought to correlate the total choline peak in breast lesions as measured by in vivo proton magnetic resonance spectroscopy ((1)H-MRS) with the CaSR expression levels in surgical specimens. PROCEDURES: Thirty-six patients with breast lesions were MR scanned at 3T scanner. Tumour morphology and DCE-MR kinetics were evaluated. (1)H-MRS was applied for Cho detection and compared with the CaSR immunohistochemistry analysis (score 0-5) on surgical breast specimens. RESULTS: Thirty-four lesions demonstrated a DCE malignant kinetics curve (types 2 and 3), while two lesions showed a benign (type 1). Twenty of the 23 breast cancer lesions (87%) with a consistent Cho peak expressed a CaSR score of 3-5, and ten of the 11 breast lesions negative for Cho (91%) had a CaSR score of 1-2. The two benign lesions showed a non-uniform/weak intense expression of the CaSR (score 3) with a consistent Cho peak. CONCLUSIONS: The presence or absence of choline peak evaluated by (1)H-MRS, well correlated with the expression of CaSR in patients with breast lesions (p < 0.01), supports the hypothesis that CaSR may play an important role in the production of choline in breast cancer.

Two-step in vivo tumor targeting by biotin-conjugated antibodies and superparamagnetic nanoparticles assessed by magnetic resonance imaging at 1.5 T.

PURPOSE: The purpose of this study was to assess two-step in vivo tumor targeting by specific biotin-conjugated antibodies and ultrasmall superparamagnetic iron oxide (USPIO)-anti-biotin nanoparticles as contrast agents for magnetic resonance imaging (MRI) at 1.5 T. PROCEDURES: D430B human lymphoma cells, expressing the CD70 surface antigen, were injected either s.c. or i.v. to induce pseudo-metastases in NOD/SCID mice. Thirty micrograms of biotin-conjugated monoclonal anti-CD70 was injected i.v., followed 4 h later by 8 micromol Fe/Kg USPIO-anti-biotin. After 24 h, MRI was performed on T2* and b-FFE sequences. Signal intensity (SI) was calculated before and after USPIO-anti-biotin administration. RESULTS: Subcutaneous xenografts showed a dishomogeneous 30% decrease in SI on T2* with anti-CD70 + USPIO-anti-biotin treatment. Pseudo-metastatic xenografts showed a slight reduction in SI on T2*, but a 60% decrease in SI on b-FFE-weighted sequences. Prussian blue staining confirmed the presence of iron nanoparticles in the excised tumors. CONCLUSION: MRI at 1.5 T can detect tumors by a two-step in vivo biotin-based protocol, which may allow the targeting of any cell surface antigen.

Use of the semiconductor nanotechnologies "quantum dots" for in vivo cancer imaging.

Non-invasive in vivo imaging offers great potential to facilitate translational drug development research at the animal testing phase. The emerging luminescent nanoparticles or quantum dots provide a new type of biological agents that can improve these applications. The advantages of luminescent nanoparticles for biological applications include their high quantum yield, color availability, good photo-stability, large surface-to-volume ratio, surface functionality, and small size. These properties could improve the sensitivity of biological detection and imaging by at least 10- to 100-fold and make them an exceptional tool for live-cell imaging. In this review patents on applications of semiconductor quantum dots for in vivo imaging are discussed.