Fluorodeoxyglucose (FDG)-Positron Emission Tomography (PET) in Cancer Associated Venothromboembolism

Summary

Venothromboembolic disease (VTE), which includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is a severe health problem, effecting 1.5/1000 per year in the general population. In patients over 60 years of age, the incidence is 1/100 per year. Of the two million Americans per year who will develop VTE, one third will develop pulmonary embolism (PE). VTE is usually diagnosed by Doppler ultrasound or contrast venography when present in the extremities, VQ scan or pulmonary angiography when PE is present. However, there are many instances when the diagnosis of VTE by conventional modalities is limited. These include obesity, recent trauma or surgery, the presence of a mass, the presence of clot around central lines, and clot occurring in the abdomen and pelvis. Furthermore, the differentiation between new and old clot has evaded all diagnostic imaging modalities, and no existing modality allows for an accurate delineation of all sites of thrombus within the body. New approaches to the diagnostic imaging of VTE in complicated cases are needed. The first hypothesis of this project is that FDG PET/CT can be used to accurately diagnose the presence and extent of acute VTE, and that it will distinguish new clot from old.

Approximately 20-25% of all new cases of venous thromboembolism occur in known cancer patients. The risk of VTE is 4-6 fold greater in patients with cancer as those without (8-12% vs. 2%, respectively, lifetime risk). In many cases, the development of VTE occurs as the first clinical sign of the cancer, even before it is diagnosed. Among patients presenting with acute VTE have no obvious cause (defined as "idiopathic" or "unprovoked", as opposed to "secondary" VTE), the literature reports that up to 20% (range of reported incidence 7-20%) may ultimately prove to have cancer, depending on the series and whether the thrombosis is unifocal or multifocal. Despite the substantial prevalence of occult cancer in patients presenting with idiopathic VTE, there are no current recommendations that these patients be screened for the presence of cancer. The second hypothesis of the project is that FDG PET/CT can accurately be used to screen for the presence of cancer in patients with unprovoked (idiopathic) acute VTE.

Objectives:

There are two specific objectives to test the hypotheses associated with this project:

1. To establish the sensitivity of FDG PET/CT in the diagnosis of acute VTE.
2. To perform a pilot project to aid in the design of a larger trial to define the incidence of occult cancer in patients rigorously selected for idiopathic (unprovoked) VTE, and to investigate the value of FDG PET in the early detection of occult cancer in this population.

Conditions

• Venothromboembolism

Interventions

PROCEDURE

FDG-PET/CT

The study is focused on two goals, both of which use a new imaging test called PET/CT. PET/CT combines a special radioactive scan with a CT scan. PET/CT is most commonly used in medical practice to evaluate cancer. Abnormal areas such as cancer "light up" on the PET/CT scan. However, many doctors, including us, have noticed that PET/CT also "lights up" in areas of blood clot formation as well. In this study, PET/CT will be used to evaluate the two goals of this project.

Sponsors & Collaborators

• National Cancer Institute (NCI)

  collaborator NIH

• University of Utah

  lead OTHER

Principal Investigators

• Kathryn Morton, MD · University of Utah

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2006-08-31

Primary Completion

2012-01-31

Completion

2012-01-31

Countries

• United States

Study Locations