A Diagnostics & Imaging Week

GE Healthcare (Waukesha, Wisconsin) reported at the annual meeting of the American Society of Clinical Oncology (ASCO) in Orlando, Florida, that it has delivered its 500th Discovery PET/CT (positron emission tomography/computed tomography) scanner, saying that the Discovery PET/CT family of scanners is the choice of seven of the top 10 U.S. cancer centers.

"When the first Discovery PET/CT was introduced four years ago, the imaging industry was revolutionized," said Hadi Moufarrej, general manager of functional imaging at GE Healthcare Technologies. "The fused information to see the anatomy laid over the metabolic activity is what makes PET/CT so powerful for oncology."

GE's Discovery CT combines PET and CT in a single, non-invasive exam to provide both metabolic and anatomic information to assist in the diagnosis, treatment planning and monitoring of cancer. The system provides lesion location and metabolic activity of growing cells to enable detection of diseases earlier to improve treatment management, according to Moufarrej.

According to GE, 2-D and 3-D imaging can enhance the image quality for patients of all sizes, reducing scatter and creating clearer views of potential lesions. The Advantage 4-D technology provides clinical information on the shape of anatomical objects in motion and identifies the range of motion, thus improving radiotherapy planning, it said.

The company also showcased enhancements to its Innova 4100 and Innova 3100 cardiovascular and interventional imaging technology, digital flat panel detector systems now incorporating 3-D models of vasculature structures that can be viewed, the company said, "in virtually any given projection for an extensive array of image information."

GE's 3-D application is a vascular X-ray acquisition mode that takes 2-D digital angiographic data acquired during high-speed spin and automatically reconstructs a 3-D model of that data. This model allows processing "and virtually unlimited projections for superb case assessment," according to Laura King, global vice president, interventional, cardiology and surgery at GE Healthcare.

"The 3-D technology provides the Innova Systems with a leading edge advance," said King. "3-D brings increased value to Innova's already high level of image quality and efficiency."

Francis Joffre, MD, chief radiologist at the University Hospital Rangueil (Toulouse, France), said GE's 3-D reconstruction has enhanced patient outcomes in various ways: "3-D allows us to better view and analyze complex anatomy. Advanced 3-D software helps to choose the optimal endovascular material when patient treatment is needed. In addition, the post procedure results complement intervention, if necessary."

In other product reports from the conference:

Imunicon (Huntingdon Valley, Pennsylvania), a developer of cell- and molecular-based diagnostic and life science research products with a focus on cancer, reported the presentation of further data from its trial in metastatic breast cancer (MBC) and the importance of circulating tumor cells (CTCs) in "non-measurable" disease.

The abstract, presented by G. Thomas Budd, MD, of the Cleveland Clinic Foundation (Cleveland), showed that the presence of five or more CTCs in a 7.5mL sample of blood from women with MBC is associated with disease progression and poor survival. The majority of the study patients had measurable disease, where tumor burden in the patient may be assessed through imaging studies. However, about 30% of MBC patients have non-measurable disease, which is defined as metastatic cancer predominantly in the bone. Such cancer is not reliably assessable by means of imaging studies.

The assessment of CTCs in 46 women with non-measurable MBC yielded similar results to the findings in women with measurable MBC. Specifically, the presence of five or more CTCs in a 7.5 mL sample of blood from such patients at three to four weeks after initiation of therapy is associated with decreased progression free survival and decreased overall survival. Thus, the presence of CTCs in these patients may be useful as a surrogate endpoint for PFS and OS and may be an earlier, more reliable predictor of outcome than traditional radiology techniques.

Veridex (Raritan, New Jersey), a business of Johnson & Johnson (New Brunswick, New Jersey), has exclusive worldwide rights to commercialize products incorporating Immunicon cell analysis technology in the cancer field. Veridex markets these products as the CellSearch System.

Immunicon says its products and underlying technology platforms also have application in the clinical development of cancer drugs and in cancer research, as well as cardiovascular and infectious diseases.

OxiGene (Waltham, Massachusetts) reported that a clinical investigator studying the company's lead vascular targeting agent, Combretastatin A4 Prodrug (CA4P), has noted that CA4P is well tolerated when combined with radiotherapy thus far in the Phase Ib portion of a planned Phase Ib/II combination trial of the compound in patients with advanced cancer. Some of these findings are contained in an abstract titled "CA4P plus Radiotherapy: Clinical Results" published for attendees at the ASCO conference. The abstract details the first 20 patients entered into the study.

Patients with inoperable, advanced non-small cell lung cancer (NSCLC), or prostate adenocarcinoma, eligible to re-ceive RT were enrolled. The first two cohorts had NSCLC, and received RT over three weeks (27Gy in six fractions). Patients in the 3rd and 4th cohorts had prostate cancer, and received RT over 4 weeks (55Gy in 20 fractions).

Patients in the 1st and 3rd cohorts received a single dose of CA4P at the completion of radiation treatment; patients in the 2nd and 4th cohorts received weekly CA4P for the duration of their RT. The authors conclude in the abstract that "CA4P is well tolerated when combined with RT. There was no increase in acute or late RT reaction, and no accumulation of toxicity with repeated doses."

ViroLogic (South San Francisco, California) reported the presentation of data demonstrating the ability of its eTag Assay System to provide a direct measure of activated vascular endothelial growth factor (VEGF) receptor type 2 (VEGFR2, also known as KDR), and its effects on downstream signal transduction pathways in an in vitro model system.

Currently, there is no direct method of detecting activated VEGFR2, and an assay able to measure this, and potentially indicate its contribution to tumor blood vessel development in individual patients, could aid in the prescription of anti-angiogenic therapies, according to ViroLogic.

"Our data in these cell lysate studies show that the eTag assay gives a direct measure of the activation of VEGFR2 and the signaling pathway it modulates," said Sharat Singh, PhD, chief technology officer, oncology, for ViroLogic and co-author of the study. "We are currently utilizing very similar eTag assays for activated EGFR receptors with human clinical samples."

He added: "We feel that the VEGFR2 assay could also be used in this setting, first as a selection tool to determine whether a VEGF pathway inhibitor, like Avastin, is an appropriate therapy for a patient, and then potentially to measure modulation of activated VEGFR2 as a marker for efficacy of certain angiogenesis inhibitors."