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The potential benefits of Reporting and Data Systems (RADS) are well known: improve the communication between the radiologists and physicians; reduce the omission of relevant information in reports; reduce the variability and errors in image interpretation; facilitate the monitoring of results and provide a tool to ensure quality and research. Furthermore, the slightest error in the interpretation of the legend describing the results of an imaging study can modify both the medical decision to start or not a treatment, and to do it with a more or less invasive technique.

By providing spatial, molecular and morphological data over time, live-cell imaging can provide a deeper understanding of the cellular and signalling events that determine cancer response to treatment. Understanding this dynamic response has the potential to enhance clinical outcome by identifying biomarkers or actionable targets to improve therapeutic efficacy. Here, we review recent applications of live-cell imaging for uncovering both tumour heterogeneity in treatment response and the mode of action of cancer-targeting drugs. Given the increasing uses of T cell therapies, we discuss the unique opportunity of time-lapse imaging for capturing the interactivity and motility of immunotherapies. Although traditionally limited in the number of molecular features captured, novel developments in multidimensional imaging and multi-omics data integration offer strategies to connect single-cell dynamics to molecular phenotypes. We review the effect of these recent technological advances on our understanding of the cellular dynamics of tumour targeting and discuss their implication for next-generation precision medicine.

BackgroundHigh-Grade Serous Ovarian Carcinoma (HGSOC) is the most prevalent and lethal subtype of ovarian cancer, but has a paucity of clinically-actionable biomarkers due to high degrees of multi-level heterogeneity. Radiogenomics markers have the potential to improve prediction of patient outcome and treatment response, but require accurate multimodal spatial registration between radiological imaging and histopathological tissue samples. Previously published co-registration work has not taken into account the anatomical, biological and clinical diversity of ovarian tumours. MethodsIn this work, we developed a research pathway and an automated computational pipeline to produce lesion-specific three-dimensional (3D) printed moulds based on preoperative cross-sectional CT or MRI of pelvic lesions. Moulds were designed to allow tumour slicing in the anatomical axial plane to facilitate detailed spatial correlation of imaging and tissue-derived data. Code and design adaptations were made following each pilot case through an iterative refinement process. ResultsFive patients with confirmed or suspected HGSOC who underwent debulking surgery between April and December 2021 were included in this prospective study. Tumour moulds were designed and 3D-printed for seven pelvic lesions, covering a range of tumour volumes (7 to 133 cm(3)) and compositions (cystic and solid proportions). The pilot cases informed innovations to improve specimen and subsequent slice orientation, through the use of 3D-printed tumour replicas and incorporation of a slice orientation slit in the mould design, respectively. The overall research pathway was compatible with implementation within the clinically determined timeframe and treatment pathway for each case, involving multidisciplinary clinical professionals from Radiology, Surgery, Oncology and Histopathology Departments. ConclusionsWe developed and refined a computational pipeline that can model lesion-specific 3D-printed moulds from preoperat

Background: Human body tissues have their own speed-of-sound (SOS) by which sound travels through them. Harder materials exhibit greater SOS; thus, SOS through each tissue can provide information regarding its elasticity. For tumor discrimination in clinical medicine, palpation provides important information. However, manual palpation is subjective, whereas SOS data are objective and can be directly used to compare lesions.Methods: A scanning acoustic microscope (SAM) uses ultrasound to image an object from SOS through tissues. We investigated the utility of SAM in imaging gastrointestinal lesions. Results: We visualized the digestive tract as a layered structure and discriminated tumors to a degree comparable with that observed by light microscopy. Areas with greater SOS corresponded to those with higher collagen or muscle fiber concentrations. Cell-poor areas or regions with degeneration demonstrated less SOS than surrounding tissues. Gastric tumors displayed appropriate SOS similar to their original tissues and showed significant differences in SOS between scirrhous carcinomas and well-differentiated medullary carcinomas, scirrhous carcinomas and malignant lymphomas, and leiomyomas and leiomyosarcomas.Conclusions: SAM offered the following benefits over LM: (1) images are acquired in a few minutes without special staining; (2) repeated observations of the same section are possible; (3) high-resolution digital imaging from SOS is comparable to LM; (4) SAM analysis could be helpful in understanding endoscopic ultrasonography imaging; and (5) digitized SOS data could be statistically compared among different stomach lesions.

Purpose: A scanning acoustic microscope (SAM) uses an ultrasound to image an object by plotting the speed-of-sound (SOS) through tissues on screen. Because hard tissues result in great SOS, SAM can provide data on the tissue elasticity. This paper investigated the utility of SAM in evaluating thyroid lesions.Methods: Formalin-fixed, paraffin sections were scanned with a 120 MHz transducer. SOS through each area was calculated and plotted on the screen to provide histological images, and SOS of each lesion was compared and statistically analyzed.Results: High-concentrated colloids, red blood cells, and collagen fibers showed great SOS, while low-concentrated colloids, parathyroids, lymph follicles, and epithelial tissues including carcinomas demonstrated lower SOS. SAM clearly discriminated structure of thyroid components corresponding to low magnification of light microscopy. Thyroid tumors were classified into three groups by average SOS: the fast group consisted of follicular adenomas/carcinomas and malignant lymphomas; the slow group contained poorly differentiated/undifferentiated carcinomas; and the intermediate group comprised papillary/medullary carcinomas. Fragmented colloids, irregular-shaped follicles, and desmoplastic reactions were observed in the invasive area of surrounding carcinomas.Conclusion: The SAM imaging method had the following benefits: 1) precise images were acquired in a few minutes without special staining; 2) structural irregularity and desmoplastic reactions, which indicated malignancy, were detected; 3) images reflected tissue elasticity, which was statistically comparable among lesions by SOS; 4) follicular functional activity was predictable by converting colloid concentration to SOS; and 5) tumor classification was predictable by SOS because more poorly differentiated carcinomas had a tendency to show lower SOS.

Treatment response assessment by imaging plays a vital role in evaluating changes in solid tumors during oncology therapeutic clinical trials. Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 is the reference standard imaging response criteria and provides details regarding image acquisition, image interpretation and categorical response classification. While RECIST 1.1 is applied for the majority of clinical trials in solid tumors, other criteria and modifications have been introduced when RECIST 1.1 outcomes may be incomplete. Available criteria beyond RECIST 1.1 can be explored in an algorithmic fashion dependent on imaging modality, tumor type and method of treatment. Positron Emission Tomography Response Criteria in Solid Tumors (PERCIST) is available for use with PET/CT. Modifications to RECIST 1.1 can be tumor specific, including mRECIST for hepatocellular carcinoma and mesothelioma. Choi criteria for gastrointestinal stromal tumors incorporate tumor density with alterations to categorical response thresholds. Prostate Cancer Working Group 3 (PCWG3) imaging criteria combine RECIST 1.1 findings with those of bone scans. In addition, multiple response criteria have been created to address atypical imaging responses in immunotherapy.

To determine whether temporal subtraction (TS) CT obtained with non-rigid image registration improves detection of various bone metastases during serial clinical follow-up examinations by numerous radiologists. Six board-certified radiologists retrospectively scrutinized CT images for patients with history of malignancy sequentially. These radiologists selected 50 positive and 50 negative subjects with and without bone metastases, respectively. Furthermore, for each subject, they selected a pair of previous and current CT images satisfying predefined criteria by consensus. Previous images were non-rigidly transformed to match current images and subtracted from current images to automatically generate TS images. Subsequently, 18 radiologists independently interpreted the 100 CT image pairs to identify bone metastases, both without and with TS images, with each interpretation separated from the other by an interval of at least 30 days. Jackknife free-response receiver operating characteristics (JAFROC) analysis was conducted to assess observer performance. Compared with interpretation without TS images, interpretation with TS images was associated with a significantly higher mean figure of merit (0.710 vs. 0.658; JAFROC analysis, P = 0.0027). Mean sensitivity at lesion-based was significantly higher for interpretation with TS compared with that without TS (46.1% vs. 33.9%; P = 0.003). Mean false positive count per subject was also significantly higher for interpretation with TS than for that without TS (0.28 vs. 0.15; P < 0.001). At the subject-based, mean sensitivity was significantly higher for interpretation with TS images than that without TS images (73.2% vs. 65.4%; P = 0.003). There was no significant difference in mean specificity (0.93 vs. 0.95; P = 0.083). TS significantly improved overall performance in the detection of various bone metastases.

Ductal carcinoma in situ (DCIS) will account for 62,930 cases of breast cancer in 2019. DCIS is a pre-invasive lesion which may not progress to invasive carcinoma, yet surgery remains the mainstay treatment. Molecular imaging of a specific marker for DCIS grade for detection and active surveillance are critically needed to reduce potential overtreatment. First, breast cancer marker B7-H3 (CD276) expression was evaluated by immunohistochemical staining in 123 human specimens including benign epithelium (H-score 10.0 ± 8.2) and low (20.8 ± 17.7), intermediate (87.1 ± 69.5), and high (159.1 ± 87.6) grade DCIS, showing a positive association with DCIS nuclear grade (P < 0.001, AUC 0.96). Next, a murine DCIS model was combined with ultrasound molecular imaging of B7-H3 targeted microbubbles to differentiate normal glands from those harboring DCIS (n = 100, FVB/N-Tg(MMTVPyMT)634Mul, AUC 0.89). Finally, photoacoustic and fluorescence molecular imaging with an anti-B7-H3 antibody-indocyanine green conjugate were utilized for DCIS detection (n = 53). Molecular imaging of B7-H3 expression may allow for active surveillance of DCIS.

Assessment of tumor-infiltrating lymphocytes (TILs) is increasingly recognized as an integral part of the prognostic workflow in triple-negative (TNBC) and HER2-positive breast cancer, as well as many other solid tumors. This recognition has come about thanks to standardized visual reporting guidelines, which helped to reduce inter-reader variability. Now, there are ripe opportunities to employ computational methods that extract spatio-morphologic predictive features, enabling computer-aided diagnostics. We detail the benefits of computational TILs assessment, the readiness of TILs scoring for computational assessment, and outline considerations for overcoming key barriers to clinical translation in this arena. Specifically, we discuss: 1. ensuring computational workflows closely capture visual guidelines and standards; 2. challenges and thoughts standards for assessment of algorithms including training, preanalytical, analytical, and clinical validation; 3. perspectives on how to realize the potential of machine learning models and to overcome the perceptual and practical limits of visual scoring.

PurposeWith the initiation of human hyperpolarized 13 C (HP-13 C) trials at multiple sites and the development of improved acquisition methods, there is an imminent need to maximally extract diagnostic information to facilitate clinical interpretation. This study aims to improve human HP-13 C MR spectroscopic imaging through means of Tensor Rank truncation-Image enhancement (TRI) and optimal receiver combination (ORC).MethodsA data-driven processing framework for dynamic HP 13 C MR spectroscopic imaging (MRSI) was developed. Using patient data sets acquired with both multichannel arrays and single-element receivers from the brain, abdomen, and pelvis, we examined the theory and application of TRI, as well as 2 ORC techniques: whitened singular value decomposition (WSVD) and first-point phasing. Optimal conditions for TRI were derived based on bias-variance trade-off.ResultsTRI and ORC techniques together provided a 63-fold mean apparent signal-to-noise ratio (aSNR) gain for receiver arrays and a 31-fold gain for single-element configurations, which particularly improved quantification of the lower-SNR-[13 C]bicarbonate and [1-13 C]alanine signals that were otherwise not detectable in many cases. Substantial SNR enhancements were observed for data sets that were acquired even with suboptimal experimental conditions, including delayed (114 s) injection (8× aSNR gain solely by TRI), or from challenging anatomy or geometry, as in the case of a pediatric patient with brainstem tumor (597× using combined TRI and WSVD). Improved correlation between elevated pyruvate-to-lactate conversion, biopsy-confirmed cancer, and mp-MRI lesions demonstrated that TRI recovered quantitative diagnostic information.ConclusionOverall, this combined approach was effective across imaging targets and receiver configurations and could greatly benefit ongoing and future HP 13 C MRI research through major aSNR improvements.

Network analysis is an important tool to analyze the structure of complex systems such as tropical forests. Here, we infer spatial proximity networks in tropical forests by using network science. First, we focus on tree neighborhoods to derive spatial tree networks from forest inventory data. In a second step, we construct species networks to describe the potential for interactions between species. We find remarkably similar tree and species networks among tropical forests in Panama, Sri Lanka and Taiwan. Across these sites only 32 to 51% of all possible connections between species pairs were realized in the species networks. The species networks show the common small-world property and constant node degree distributions not yet described and explained by network science. Our application of network analysis to forest ecology provides a new approach in biodiversity research to quantify spatial neighborhood structures for better understanding interactions between tree species. Our analyses show that details of tree positions and sizes have no important influence on the detected network structures. This suggests existence of simple principles underlying the complex interactions in tropical forests.

Assessment of tumor-infiltrating lymphocytes (TILs) is increasingly recognized as an integral part of the prognostic workflow in triple-negative (TNBC) and HER2-positive breast cancer, as well as many other solid tumors. This recognition has come about thanks to standardized visual reporting guidelines, which helped to reduce inter-reader variability. Now, there are ripe opportunities to employ computational methods that extract spatio-morphologic predictive features, enabling computer-aided diagnostics. We detail the benefits of computational TILs assessment, the readiness of TILs scoring for computational assessment, and outline considerations for overcoming key barriers to clinical translation in this arena. Specifically, we discuss: 1. ensuring computational workflows closely capture visual guidelines and standards; 2. challenges and thoughts standards for assessment of algorithms including training, preanalytical, analytical, and clinical validation; 3. perspectives on how to realize the potential of machine learning models and to overcome the perceptual and practical limits of visual scoring., SCOPUS: re.j, info:eu-repo/semantics/published

In the recent years, targeted cancer theranosis, the concomitant therapeutic treatment and selective visualization of cancerous tissue, has become a powerful strategy to improve patient prognosis. In this context, targeted multimodal molecular imaging, the combination of different imaging modalities overcoming their individual limitations, has attracted great attention. Due to their unique properties, advanced nanomaterials have taken center stage in the development of theranostics. In this work, we report a novel Janus nanoplatform by combining an Fe3O4 NPs/mesoporous silica core@shell face together with an Au nanoparticle face. Due to its anisotropy, this hybrid nanomaterial enabled the orthogonal site-selective modification of each face permitting the incorporation of a targeting peptide for cancer detection (cRGD) and a fluorescent dye. Due to the intrinsic characteristics of this Janus nanoplatform together with those selectively generated on their surfaces, the resulting hybrid nanocarrier successfully promoted the in vivo tumor-targeted multimodal imaging by magnetic resonance (Fe3O4 core), computed tomography (AuNP face), and fluorescent tracking (fluorescent dye loading) in a fibrosarcoma-bearing mouse model. The achieved results endorse these hybrid Janus nanoparticles as a powerful and flexible platform with integrated imaging and carrier functionalities to be equipped with therapeutic features to generate an advanced multifunctional nanocarrier for targeted cancer theranosis., Ministerio de Ciencia, Innovación y Universidades (España), Ministerio de Economia y Competitividad (España), Comunidad de Madrid, European Commission, Depto. de Química Analítica, Fac. de Ciencias Químicas, TRUE, pub

PurposeTo assess the utility of furosemide diuresis and the role of an improved scatter correction algorithm in reducing scatter artifact severity on Ga-68- Prostate-specific membrane antigen (PSMA)-11 positron emission tomography (PET).Materials and methodsA total of 139 patients underwent Ga-68-PSMA-11 PET imaging for prostate cancer: 47 non-time-of-flight (non-TOF) PET/computed tomography, 51 PET/magnetic resonance imaging (MRI) using the standard TOF scatter correction algorithm, and 41 PET/MRI using an improved TOF scatter correction algorithm. Whole-body PET acquisitions were subdivided into 3 regions: around kidneys; between kidneys and bladder; and around bladder. The images were reviewed, and scatter artifact severity was rated using a Likert-type scale.ResultsThe worst scatter occurred when using non-TOF scatter correction without furosemide, where 42.1% of patients demonstrated severe scatter artifacts in 1 or more regions. Improved TOF scatter correction resulted in the smallest percentage of studies with severe scatter (6.5%). Scatter ratings by region were lowest using improved TOF scatter correction. Furosemide reduced mean scatter severity when using non-TOF and standard TOF.ConclusionsBoth furosemide and scatter correction algorithm play a role in reducing scatter in PSMA PET. Improved TOF scatter correction resulted in the lowest scatter severity.

Fluoromagnetic systems are recognized as an emerging class of materials with great potential in the biomedical field. Here, it is shown how to fabricate fluoromagnetic nanotubes that can serve as multimodal probes for the imaging and targeting of brain cancer. An ionic self-assembly strategy is used to functionalize the surface of synthetic chrysotile nanotubes with pH-sensitive fluorescent chromophores and ferromagnetic nanoparticles. The acquired magnetic properties permit their use as contrast agent for magnetic resonance imaging, and enable the tracking of tumor cell migration and infiltration responsible for metastatic growth and disease recurrence. Their organic component, changing its fluorescence attitude as a function of local pH, targets the cancer distinctive acidity, and allows localizing and monitoring the tumor occurrence and progression by mapping the acidic spatial distribution within biopsy tissues. The fluoromagnetic properties of nanotubes are preserved from the in vitro to the in vivo condition and they show the ability to migrate across the blood brain barrier, thus spontaneously reaching the brain tumor after injection. The simplicity of the synthesis route of these geomimetic nanomaterials combined with their demonstrated affinity with the in vivo condition strongly highlights their potential for developing effective functional materials for multimodal theranostics of brain cancer

Acido-Chemical Exchange Saturation Transfer (acidoCEST) Magnetic Resonance Imaging (MRI) is a non-invasive method for creating spatial maps of the extracellular pH (pHe) in solid tissues in vivo. Cancer cells are known to export increased quantities of lactic acid into the extracellular space as a result of glycolytic metabolic processes. Localized tissue acidosis can therefore function as a cancer biomarker, and acidoCEST MRI may be an impactful tool for increasing the specificity of imaging results. My work has focused on applying acidoCEST MRI to the diagnosis of lung cancer, where low-dose CT screening tests have a false positive rate of 95%. Chapter 1 discusses recent advances in MRI for the diagnosis, prognosis and management of pulmonary disease. Chapter 2 refers to a published manuscript reprinted in Appendix A which describes a method comparison study wherein I determined that the exchange rate (kex) of amide protons quantified by endogenous CEST MRI could not serve as a proxy measurement for pHe quantified by acidoCEST MRI. Chapter 3 describes a study in which I determined that lung tumors and valley fever granulomas in preclinical murine models have significantly different pHe. Chapter 4 discusses future directions of inquiry towards diagnostic CEST MRI methods for lung cancer including: application of endogenous CEST MRI, further development of the BSL-2 compatible murine valley fever model, and potential improvements to acidoCEST MRI image acquisition and analysis methods to aid in future clinical translation.

Recent technical advances in positron emission tomography/magnetic resonance imaging (PET/MRI) technology allow much improved time-of-flight (TOF) and regularized iterative PET reconstruction regularized iterative reconstruction (RIR) algorithms. We evaluated the effect of TOF and RIR on standardized uptake values (maximum and peak SUV [SUVmax and SUVpeak]) and their metabolic tumor volume dependencies and visual image quality for 18F-fluorocholine PET/MRI in patients with newly diagnosed prostate cancer. Fourteen patients were administered with 3 MBq/kg of 18F-fluorocholine and scanned dynamically for 30 minutes. Positron emission tomography images were divided to early and late time points (1-6 minutes summed and 7-30 minutes summed). The values of the different SUVs were documented for dominant PET-avid lesions, and metabolic tumor volume was estimated using a 50% isocontour and SUV threshold of 2.5. Image quality was assessed via visual acuity scoring (VAS). We found that incorporation of TOF or RIR increased lesion SUVs. The lesion to background ratio was not improved by TOF reconstruction, while RIR improved the lesion to background ratio significantly ( P < .05). The values of the different VAS were all significantly higher ( P < .05) for RIR images over TOF, RIR over non-TOF, and TOF over non-TOF. In conclusion, our data indicate that TOF or RIR should be incorporated into current protocols when available.

The imaging of drugs inside tissues is pivotal in oncology to assess whether a drug reaches all cells in an adequate enough concentration to eradicate the tumor. Matrix-Assisted Laser Desorption Ionization Mass Spectrometry Imaging (MALDI-MSI) is one of the most promising imaging techniques that enables the simultaneous visualization of multiple compounds inside tissues. The choice of a suitable matrix constitutes a critical aspect during the development of a MALDI-MSI protocol since the matrix ionization efficiency changes depending on the analyte structure and its physico-chemical properties. The objective of this study is the improvement of the MALDI-MSI technique in the field of pharmacology; developing specifically designed nanostructured surfaces that allow the imaging of different drugs with high sensitivity and reproducibility. Among several nanomaterials, we tested the behavior of gold and titanium nanoparticles, and halloysites and carbon nanotubes as possible matrices. All nanomaterials were firstly screened by co-spotting them with drugs on a MALDI plate, evaluating the drug signal intensity and the signal-to-noise ratio. The best performing matrices were tested on control tumor slices, and were spotted with drugs to check the ion suppression effect of the biological matrix. Finally; the best nanomaterials were employed in a preliminary drug distribution study inside tumors from treated mice.

Protein cage architectures such as viral capsids, heat shock proteins, and ferritins are naturally occurring nanoscale structures with exquisite homogeneity and stability. This dissertation work describes endeavors toward the use of three different protein cage architectures: the MS2 bacteriophage, a mutant of the Tobacco Mosaic Virus (TMV), and the nanophage scaffold (derived from fd phage) as therapeutic and imaging agent delivery systems. The cages were reacted with several types of organic molecules, such as drug molecules, imaging tracers, and targeting ligands. Towards the development of the platforms for therapeutic delivery, the antitumor agent doxorubicin was covalently bound on the protein scaffolds via a pH sensitive linker. The effects of these constructs on cultured mammalian cells, their biocompatibility, in vivo tumor homing and biodistribution were investigated. Tumor growth inhibition studies were also performed with these structures. Together, the results presented herein demonstrate the utility of the protein cages as robust nanoscale platforms for the delivery of cargo.

Full-text article is free to read on the publisher's website Purpose Positron emission tomography using ligands targeting prostate specific membrane antigen has recently been introduced. Positron emission tomography imaging with 68Ga-PSMA-HBED-CC has been shown to detect metastatic prostate cancer lesions at a high rate. In this study we compare multiparametric magnetic resonance imaging and prostate specific membrane antigen positron emission tomography of the prostate with whole mount ex vivo prostate histopathology to determine the true sensitivity and specificity of these imaging modalities for detecting and locating tumor foci within the prostate. Materials and Methods In a prospective clinical trial setting 20 patients with localized prostate cancer and a planned radical prostatectomy were recruited. All patients underwent multiparametric magnetic resonance imaging and positron emission tomography before surgery, and whole mount histopathology slides were directly compared to the images. European Society of Urogenital Radiology guidelines for reporting magnetic resonance imaging were used as a template for regional units of analysis. The uropathologist and radiologists were blinded to individual components of the study, and the final correlation was performed by visual and deformable registration analysis. Results A total of 50 clinically significant lesions were identified from the whole mount histopathological analysis. Based on regional analysis the sensitivity, specificity, positive predictive value and negative predictive value for multiparametric magnetic resonance imaging were 44%, 94%, 81% and 76%, respectively. With prostate specific membrane antigen positron emission tomography the sensitivity, specificity, positive predictive value and negative predictive value were 49%, 95%, 85% and 88%, respectively. Prostate specific membrane antigen positron emission tomography yielded a higher specificity and positive pred

Purpose To develop a novel tracer-kinetic modeling approach for multi-agent dynamic contrast-enhanced MRI (DCE-MRI) that facilitates separate estimation of parameters characterizing blood flow and microvascular permeability within one individual. Methods Monte Carlo simulations were performed to investigate the performance of the constrained multi-agent model. Subsequently, multi-agent DCE-MRI was performed on tumor-bearing mice (n = 5) on a 7T Bruker scanner on three measurement days, in which two dendrimer-based contrast agents having high and intermediate molecular weight, respectively, along with gadoterate meglumine, were sequentially injected within one imaging session. Multi-agent data were simultaneously fit with the gamma capillary transit time model. Blood flow, mean capillary transit time, and bolus arrival time were constrained to be identical between the boluses, while extraction fractions and washout rate constants were separately determined for each agent. Results Simulations showed that constrained multi-agent model regressions led to less uncertainty and bias in estimated tracer-kinetic parameters compared with single-bolus modeling. The approach was successfully applied in vivo, and significant differences in the extraction fraction and washout rate constant between the agents, dependent on their molecular weight, were consistently observed. Conclusion A novel multi-agent tracer-kinetic modeling approach that enforces self-consistency of model parameters and can robustly characterize tumor vascular status was demonstrated.

The objective of this study was to evaluate the potentialof PEGylated 64Cu-liposomes in clinical diagnosticpositron emission tomography (PET) imaging andPEGylated 177Lu-liposomes in internal tumor radiotherapythrough in vivo characterization and dosimetric analysis in ahuman xenograft mouse model. Liposomes with 5 and 10 mol% PEG were characterizedwith respect to size, charge, and 64Cu- and 177Lu-loadingefficiency. The tumor imaging potential of 64Cu-loadedliposomes was evaluated in terms of in vivo biodistribution,tumor accumulation and tumor-to-muscle (T/M) ratios, usingPET imaging. The potential of PEGylated liposomes for diagnosticand therapeutic applications was further evaluatedthrough dosimetry analysis using OLINDA/EXM software.The 64Cu-liposomes were used as biological surrogates toestimate the organ and tumor kinetics of 177Lu-liposomes.High remote loading efficiency (>95 %) was obtainedfor both 64Cu and 177Lu radionuclides with PEGylated liposomes,and essentially no leakage of the encapsulated radionuclidewas observed upon storage and after serum incubationfor 24 h at 37 °C. The 10 mol% PEG liposomes showedhigher tumor accumulation (6.2±0.2 %ID/g) than the 5mol% PEG liposomes, as evaluated by PET imaging. Thedosimetry analysis of the 64Cu-liposomes estimated an acceptabletotal effective dose of 3.3·10−2 mSv/MBq for diagnosticimaging in patients. A high absorbed tumor dose (114 mGy/MBq) was estimated for the potential radiotherapeutic 177Luliposomes. The overall preclinical profile of PEGylated64Cu-liposomes showed high potential as a new PETtheranostic tracer for imaging in humans. Dosimetry resultspredicted that initial administered activity of 200 MBq of64Cu-liposomes should be acceptable in patients. Work is inprogress to validate the utility of PEGylated 64Cu-liposomesin a clinical research programme. The high absorbed tumordose (114 mGy/MBq) estimated for 177Lu-liposomes and thepreliminary dosimetric studies justify further therapeutic anddosimetr

Magnetic resonance imaging (MRI) of glioblastoma multiforme (GBM) with molecular imaging agents would allow for the specific localization of brain tumors. Prior studies using T 1-weighted MR imaging demonstrated that the SBK2-Tris-(Gd-DOTA)3 molecular imaging agent labeled heterotopic xenograft models of brain tumors more intensely than non-specific contrast agents using conventional T 1-weighted imaging techniques. In this study, we used a dynamic quantitative T 1 mapping strategy to more objectively compare intra-tumoral retention of the SBK2-Tris-(Gd-DOTA)3 agent over time in comparison to non-targeted control agents. Our results demonstrate that the targeted SBK2-Tris-(Gd-DOTA)3 agent, a scrambled-Tris-(Gd-DOTA)3 control agent, and the non-specific clinical contrast agent Optimark(™) all enhanced flank tumors of human glioma cells with similar maximal changes on T 1 mapping. However, the retention of the agents differs. The non-specific agents show significant recovery within 20 min by an increase in T 1 while the specific agent SBK2-Tris-(Gd-DOTA)3 is retained in the tumors and shows little recovery over 60 min. The retention effect is demonstrated by percent change in T 1 values and slope calculations as well as by calculations of gadolinium concentration in tumor compared to muscle. Quantitative T 1 mapping demonstrates the superior binding and retention in tumors of the SBK2-Tris-(Gd-DOTA)3 agent over time compared to the non-specific contrast agent currently in clinical use.

Background: 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) has proven to be of substantial benefit in imaging of sarcoma patients. We therefore investigated the feasibility and benefit of combined PET/magnetic resonance imaging (MRI). Methods: Twelve patients with sarcoma who underwent FDG PET/MRI for staging and response assessment after chemotherapy were included. Results: Based on contrast-enhanced MRI and application of Choi criteria, therapy response was classified as stable disease in 6/12 patients (50%) and as partial remission in 6/12 patients (50%). Conclusion: In sarcoma patients, response assessment using Choi criteria based on contrast-enhanced MRI in comparison to FDG PET imaging only demonstrates slight correlation.

By using efficient synthetic protocols to conjugate small molecules to phage coat proteins, we can directly convert cell surface marker specific phage isolated from library screens into imaging agents that can target and differentiate breast cancer tissues. In the current work, I have utilized phage evolved to target HER3, CD44, and CD73 cell surface proteins, in addition to those previously described that bind EGFR and HER2. The abilities of the modified phage to bind their targeted cell surface receptors following chemical manipulations were evaluated in vitro by using flow cytometry and confocal microscopy assays, and it was found that the synthetic modifications performed did not significantly alter phage binding ability. Experiments in vivo with mouse xenograft models were used to determine biodistribution and tumor targeting abilities of the agents in a physiological setting. Follow-up experiments using radio-tracers for thorough evaluation of bio-distribution and stability are currently in progress. Phage were also explored as agents for immunofluorescence staining of breast cancer tissues as a surrogate for tumor binding.

We report a convenient new technique for the labeling of filamentous phage capsid proteins. Previous reports have shown that phage coat protein residues can be modified, but the lack of chemically distinct amino acids in the coat protein sequences makes it difficult to attach high levels of synthetic molecules without altering the binding capabilities of the phage. To modify the phage with polymer chains, imaging groups, and other molecules, we have developed chemistry to convert the N-terminal amines of the ~4200 coat proteins into ketone groups. These sites can then serve as chemospecific handles for the attachment of alkoxyamine groups through oxime formation. Specifically, we demonstrate the attachment of fluorophores and up to 3000 molecules of 2 kDa poly(ethylene glycol) (PEG2k) to each of the phage capsids without significantly affecting the binding of phage-displayed antibody fragments to EGFR and HER2 (two important epidermal growth factor receptors). We also demonstrate the utility of the modified phage for the characterization of breast cancer cells using multicolor fluorescence microscopy. Due to the widespread use of filamentous phage as display platforms for peptide and protein evolution, we envision that the ability to attach large numbers of synthetic functional groups to their coat proteins will be of significant value to the biological and materials communities.

We previously developed a self-referencing differential spectroscopic (SRDS) method to detect lesions by identifying a spectroscopic biomarker of breast cancer, i.e., the specific tumor component (STC). The SRDS method is based on the assumption of the exclusive presence of this spectroscopic biomaker in malignant disease. Although clinical results using this method have already been published, the dependence of the STC spectra on the choice of reference tissue has not yet been addressed. In this study, we explore the impact of the selection of the reference region size and location on the STC spectrum in 10 subjects with malignant breast tumors. Referencing from both contralateral and ipsilateral sides was performed. Regardless of the referencing, we are able to obtain consistent high contrast images of malignant lesions using the STC with less than 13% deviation. These results suggest that the STC measurements are independent of any type, location, and amount of normal breast tissue used for referencing. This confirms the initial assumption of the SRDS analysis, that there are specific tumor components in cancer that do not exist in normal tissue. This also indicates that bilateral measurements are not required for lesion identification using the STC method.

This report summarizes the efforts of our team consisting of researchers from Rice University and M. D. Anderson Cancer Center, in the DoD funded CDMRP award towards the development of an integrated nano particle based imaging and therapy of breast cancer. We have used both gold nano particles (Au-NPs) and gold nanoshells for specifically targeting cancer cells. This has been accomplished in two ways. First by attaching anti-human epidermal growth factor receptor 2 (anti-HER 2) antibodies to gold nanoshells for targeting HER 2 expressing SK-BR3 breast carcinoma cells. The second approach is by building biologically active networks of Au-NP and bacteriophages which can be used as in vivo biological sensors for non invasive optical molecular fingerprinting, and cell targeting agents., The original document contains color images.

During the last Fiscal Year of the award, the Cancer Institute of Long Island benefited from CPMRP funding in a manner consistent with the proposed activities of the award. In the area of core instrumentation acquisition, the Applied Biosystems, Inc. Q-Star LC/MS/MS Mass Spectrometer that was acquired in Year 1 became fully operational and has supported research for 21 cancer investigators from 7 different departments. Data for several publications and new grants are being organized and the instrumentation is a widely accepted successful edition to the Cancer Proteomics initiative. Additionally, another research grade ABI MALDI-ToF was acquired, as well as preparatory robots to aid in spot excision and gel digestion. More recently, as specified in Year 2, much time was spent investigating and considering the best option for a 2-photon confocal microscope. Upon the conclusion of this process a Carl Zeiss Inc. Inverted Multi-Photon system was selected. The instrument is to be sited and operated in a class 100,000 clean room and located in a shared instrument facility contiguous to the cancer marker diagnostics laboratory as well as many other cancer research groups. The technology offers a new and exciting platform for cancer imaging and has been equipped to enable the imaging of living cells. Leading this project is the thematic program director, and now chair of the Department of Molecular Genetics and Microbiology, Dr. Dafna Bar-Sagi. A faculty member skilled in 2-Photon Microscopy will provide daily oversight for the instrument, and a PhD-level optical physicist will be recruited to operate the instrument. The instrument will be installed in September 2003. Consistent with the funding for this initiative was the granting of Research Support Units. These units serve to assist in the recruitment of new, well-trained cancer researchers. Each package provided support for laboratory personnel, small or specialized research equipment, and supplies.