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Daniel C Sullivan

Publications and source records attributed to Daniel C Sullivan.

13 recordsLinked to original sources
PubMed2006

I2 imaging: cancer biology and the tumor microenvironment.

The use of imaging techniques to understand the role of the tumor microenvironment in cancer progression was the topic of a National Cancer Institute (NCI)-sponsored think tank entitled "I2 Imaging: Cancer Biology and the Tumor Microenvironment," held in Alexandria, Virginia on June 8 to 10, 2006. Participants discussed both recent progress in the use of imaging to dissect cellular and molecular interactions within the tumor microenvironment and the challenges that remain. Recommendations made to the NCI included (a) holding an annual meeting at which biologists, clinicians, and imaging scientists could exchange data, facilitating new collaborations within this multidisciplinary field; (b) funding both research and training specifically designed to foster a cross-disciplinary focus; (c) creating and making available a variety of resources to interested investigators, such as a repository of stromal cells and extracellular matrix molecules; and (d) taking steps to encourage translation of the basic research findings into the clinic.

Biomedical Research↗
PubMed2005

The progress and promise of molecular imaging probes in oncologic drug development.

As addressed by the recent Food and Drug Administration Critical Path Initiative, tools are urgently needed to increase the speed, efficiency, and cost-effectiveness of drug development for cancer and other diseases. Molecular imaging probes developed based on recent scientific advances have great potential as oncologic drug development tools. Basic science studies using molecular imaging probes can help to identify and characterize disease-specific targets for oncologic drug therapy. Imaging end points, based on these disease-specific biomarkers, hold great promise to better define, stratify, and enrich study groups and to provide direct biological measures of response. Imaging-based biomarkers also have promise for speeding drug evaluation by supplementing or replacing preclinical and clinical pharmacokinetic and pharmacodynamic evaluations, including target interaction and modulation. Such analyses may be particularly valuable in early comparative studies among candidates designed to interact with the same molecular target. Finally, as response biomarkers, imaging end points that characterize tumor vitality, growth, or apoptosis can also serve as early surrogates of therapy success. This article outlines the scientific basis of oncology imaging probes and presents examples of probes that could facilitate progress. The current regulatory opportunities for new and existing probe development and testing are also reviewed, with a focus on recent Food and Drug Administration guidance to facilitate early clinical development of promising probes.

Antineoplastic Agents↗
PubMed2005

Functional imaging in lung cancer.

Accurate detection of the presence and extent of disease is vital in the management of non-small-cell lung cancer. While computed tomography and magnetic resonance imaging tend to be the routine diagnostic modalities used in the management of lung cancer, there have been significant advances in the field of functional and molecular imaging. In this article, we review the performance of the functional imaging techniques that are currently available for the evaluation of non-small-cell lung cancer. The techniques range from evaluation of glucose metabolism in tumors with fluorodeoxyglucose, to evaluation of proliferation with fluorothymidine and evaluation of tumor hypoxia with agents such as fluoromisonidazole. Magnetic resonance imaging with an emphasis on dynamic contrast enhancement of tumors as well as detecting of malignant lymph nodes with targeted contrast agents is discussed. Emerging technologies such as lung imaging fluorescence endoscopy are considered. The role of functional imaging in planning, predicting response to, and evaluating effects of, various therapies is explored.

Carcinoma, Non-Small-Cell Lung↗
PubMed2005

Progress and promise of FDG-PET imaging for cancer patient management and oncologic drug development.

2-[(18)F]Fluoro-2-deoxyglucose positron emission tomography (FDG-PET) assesses a fundamental property of neoplasia, the Warburg effect. This molecular imaging technique offers a complementary approach to anatomic imaging that is more sensitive and specific in certain cancers. FDG-PET has been widely applied in oncology primarily as a staging and restaging tool that can guide patient care. However, because it accurately detects recurrent or residual disease, FDG-PET also has significant potential for assessing therapy response. In this regard, it can improve patient management by identifying responders early, before tumor size is reduced; nonresponders could discontinue futile therapy. Moreover, a reduction in the FDG-PET signal within days or weeks of initiating therapy (e.g., in lymphoma, non-small cell lung, and esophageal cancer) significantly correlates with prolonged survival and other clinical end points now used in drug approvals. These findings suggest that FDG-PET could facilitate drug development as an early surrogate of clinical benefit. This article reviews the scientific basis of FDG-PET and its development and application as a valuable oncology imaging tool. Its potential to facilitate drug development in seven oncologic settings (lung, lymphoma, breast, prostate, sarcoma, colorectal, and ovary) is addressed. Recommendations include initial validation against approved therapies, retrospective analyses to define the magnitude of change indicative of response, further prospective validation as a surrogate of clinical benefit, and application as a phase II/III trial end point to accelerate evaluation and approval of novel regimens and therapies.

Fluorodeoxyglucose F18↗
PubMed2004

Nanotechnology and tumor imaging: seizing an opportunity.

Nanoparticles, labeled with a signaling moiety for in vivo imaging, and one or more ligands for molecularly targeted specificity, hold considerable promise in oncology. Nanoparticles can serve as modular platforms, from which a wide variety of highly sensitive and specific imaging agents can be created. For example, many hundreds or thousands of atoms that provide imaging signals, such as radioisotopes, lanthanides, or fluorophores, can be attached to each nanoparticle, to form imaging agents that would provide higher sensitivity that can be obtained from agents based on small molecules. Similarly, many copies of targeted ligands can be attached to nanoparticles to markedly increase specific binding. Drugs or therapeutic isotopes can be added to create multifunctional nanoparticles. Appropriately labeled and targeted nanoparticles could lead to a paradigm change in which cancer detection, diagnosis, and therapy are combined in a single molecular complex.

Humans↗
PubMed2002

Factors affecting patient enrollment in radiology clinical trials: a case study of the American College of Radiology Imaging Network.

RATIONALE AND OBJECTIVES: This study was designed to identify factors that affect the enrollment of patients into American College of Radiology Imaging Network clinical trials. MATERIALS AND METHODS: A quality improvement study was performed. Brainstorming produced an exhaustive list of factors that could affect the interest of sites in participating in American College of Radiology Imaging Network trials, as well as factors that could influence patient recruitment. Surveys, structured interviews, and benchmarking were used to validate and rank the importance of these factors. RESULTS: Site participation was influenced mainly by the support of the department chair and the interest of the investigator. Patient recruitment was affected primarily by the ease of identifying candidates and the perceived experience level and skill of the support staff. CONCLUSION: Because radiologists do not control patient referrals for imaging tests, a premium must be placed on developing systems to maximize the identification and enrollment of candidates for clinical trials. Other factors considered critical to success in patient enrollment include the supportiveness of the departmental leadership, the experience and skill level of study personnel, and the availability of site-specific infrastructure to support the study.

Attitude of Health Personnel↗
PubMed2002

Challenges and opportunities for in vivo imaging in oncology.

Advances in genomics, proteomics and technology are changing medicine in fundamental ways. There are increasing clinical and laboratory requirements to obtain cellular and molecular information in vivo. This is particularly true in oncology, where the behavior of tumor cells is inextricably linked to their milieu. If cancer cells are removed from their microenvironment, their pattern of gene expression changes. Therefore, non-invasive, quantitative means of detecting gene and protein activity are essential. In vivo imaging is one methodology for achieving this. Marked advances in tracer methods for PET scanning or single-photon nuclear medicine techniques have occurred in the past few years. MRI contrast agents that reflect physiologic information are also being developed, although larger mass quantities of injectable material are required. The useful concept of "activatable agents" was pioneered in MRI. Similarly, ultrasound and computed tomography are being re-engineered to reflect information at the cellular level. In vivo optical imaging technologies have matured to the point where they are indispensable laboratory tools for small animal imaging. Human applications are in the feasibility testing stage, and the future for clinical optical imaging techniques looks bright. Merging these molecular imaging techniques with minimally or non-invasive image-guided therapeutic delivery techniques is a subsequent goal in the fight against cancer.

Humans↗
PubMedDate not supplied

Meeting report: high-throughput technologies for in vivo imaging agents.

Combinatorial chemistry and high-throughput screening have become standard tools for discovering new drug candidates with suitable pharmacological properties. Now, those same technologies are starting to be applied to the problem of discovering novel in vivo imaging agents. Important differences in the biological and pharmacological properties needed for imaging agents, compared to those for a therapeutic agent, require new screening methods that emphasize those characteristics, such as optimized residence time and tissue specificity, that make for a good imaging agent candidate.

Animals↗