Track topics on Twitter Track topics that are important to you
- Tc-94m sestamibi accumulates in tumor cells and is eliminated from them in much the same way that some chemotherapy drugs are eliminated from cancer cells in patients with drug resistance.
- P-glycoprotein is a protein found on the surface of some cancer cells. The protein causes the cells to pump out, or reject, some types of chemotherapy drugs. P-glycoprotein also makes the cells reject sestamibi.
- Some drugs, including a drug called tariquidar, may block the pumping action of P-glycoprotein, giving the chemotherapy more time to work. Tariquidar can also help sestamibi stay in the cells longer.
-To evaluate the use of sestamibi for determining if chemotherapy is being rejected and if enough of the blocking drugs are present to stop the rejection.
-Patients18 years of age and older with a tumor 2 cm or larger who are enrolled in or are eligible for enrollment in an active National Cancer Institute treatment protocol.
- Patients have two scans, one before receiving any drugs and a second 1-2 hours after receiving tariquidar. The second scan is done 72 or more hours after the first. For both scans, Tc-94m sestamibi is injected into a vein and a series of pictures are taken with an imaging camera called a PET scanner. The pictures show where the sestamibi distributes in the body and monitors the effects of tariquidar on drug resistance. Blood samples are collected during the scan to examine the effect of tariquidar on P-glycoprotein in normal cells.
- Some patients may be asked to undergo a tumor biopsy to test for the presence of the P-glycoprotein on their cancer cells. This will be requested only in patients whose tumor is easily accessible and in whom a biopsy can be done with minimal risk.
- A pilot study of PET imaging with Tc-94m sestamibi to assess activity of the multidrug transporter, MDR-1/P-glycoprotein, an ATP-binding cassette protein that transports drug out of the cell, thereby reducing intracellular drug accumulation.
- Tariquidar is a safe, nontoxic antagonist of P-glycoprotein. Previous studies demonstrated that tariquidar increased retention of the radioimaging agent, Tc99 sestamibi in normal liver and in a subset of tumors. These studies were limited by the semiquantitative nature of total body imaging by conventional radionuclide scintigraphy
- In collaboration with the Clinical Center Nuclear Medicine Department, a PET imaging agent has been developed, Tc-94m sestamibi, and the FDA has granted approval for its use in humans.
-To evaluate the feasibility of Tc-94m sestamibi as a PET imaging agent, which should allow greater resolution and quantitation and thereby make possible direct quantitative comparisons of tumor uptake before and after treatment with a P-glycoprotein antagonist.
- Patients over 18 years of age, who are eligible for, or have completed enrollment in an active NCI protocol for treatment of cancer.
- Negative pregnancy test within 24 hrs of Tc-94m injection.
- An index lesion greater than 2cm will be required to optimize the PET images.
- Prior treatment with a P-glycoprotein antagonist is allowed.
- Designed as a feasibility study. Patients meeting the eligibility criteria and signing informed consent will undergo a PET sestamibi imaging scan in the Department of Nuclear Medicine. Seventy-two hours later, a dose of tariquidar will be administered before a repeat imaging study.
- Blood will be obtained for analysis of the pharmacokinetics of Tc-94m sestamibi, and for isolation of peripheral blood mononuclear cells to assay P-glycoprotein inhibition in circulating CD56+ cells. These assessments are needed to confirm the impact of tariquidar on P-glycoprotein in normal cells - for example, those involved in drug excretion and in circulating mononuclear cells. These results will then be used to inform the findings in the PET imaging study.
- Fifteen patients will be enrolled and pairwise comparisons will be made between the sestamibi residence times in tumor, normal liver, kidney, and heart. All comparisons are noted to be exploratory.
Primary Purpose: Treatment
Tariquidar, Tc-94m Sestamibi, positron emission tomography, radionuclide imaging
National Institutes of Health Clinical Center, 9000 Rockville Pike
National Institutes of Health Clinical Center (CC)
Published on BioPortfolio: 2014-08-27T03:54:25-0400
RATIONALE: Imaging procedures such as positron emission tomography may improve the ability to determine the stage of esophageal cancer. PURPOSE: This clinical trial is studying how well f...
RATIONALE: New imaging procedures such as fludeoxyglucose F 18 positron emission tomography (FDG-PET) and magnetic resonance (MR) perfusion imaging may improve the ability to detect diseas...
RATIONALE: Imaging procedures, such as positron emission tomography (PET), may improve the ability to detect the extent of non-small cell lung cancer. PURPOSE: Diagnostic trial to study t...
This clinical trial studies positron emission tomography imaging in using copper Cu 64 TP3805in patients with breast cancer. Diagnostic procedures, such as positron emission tomography (PE...
Rationale: Diagnostic procedures, such as positron emission tomography (PET) using fluorodeoxyglucose (FDG), may help determine response to standard cancer therapy in patients with cervic...
The pleura may be affected by primary tumors or metastatic spread of intrathoracic or extrathoracic neoplasms. Primary pleural neoplasms represent ∼10% of all pleural tumors, and malignant lesions a...
Positron emission tomography scanning is not commonly performed in pregnancy but can be done if required. Fetal doses of radiation can be minimized, and our case exemplifies the safe application of po...
Early Cardiac Involvement Affects Left Ventricular Longitudinal Function in Females Carrying α-Galactosidase A Mutation: Role of Hybrid Positron Emission Tomography and Magnetic Resonance Imaging and Speckle-Tracking Echocardiography.
HybridF-fluorodeoxyglucose (FDG) positron emission tomography and magnetic resonance imaging may differentiate mature fibrosis or scar from fibrosis associated to active inflammation in patients with ...
11C-Methionine Positron Emission Tomography/Computed Tomography Versus 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Evaluation of Residual or Recurrent World Health Organization Grades II and III Meningioma After Treatment.
The aim of this study was to determine the assessment of positron emission tomography-computed tomography using C-methionine (MET PET/CT) for World Health Organization (WHO) grades II and III meningio...
An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.
An imaging technique that combines a POSITRON-EMISSION TOMOGRAPHY (PET) scanner and a CT X RAY scanner. This establishes a precise anatomic localization in the same session.
The creation of a visual display of the inside of the entire body of a human or animal for the purposes of diagnostic evaluation. This is most commonly achieved by using MAGNETIC RESONANCE IMAGING; or POSITRON EMISSION TOMOGRAPHY.
A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.
An imaging technique using a device which combines TOMOGRAPHY, EMISSION-COMPUTED, SINGLE-PHOTON and TOMOGRAPHY, X-RAY COMPUTED in the same session.
Clinical Approvals Clinical Trials Drug Approvals Drug Delivery Drug Discovery Generics Drugs Prescription Drugs In the fields of medicine, biotechnology and pharmacology, drug discovery is the process by which drugs are dis...
Food is any substance consumed to provide nutritional support for the body. It is usually of plant or animal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism ...
Pharmacy is the science and technique of preparing as well as dispensing drugs and medicines. It is a health profession that links health sciences with chemical sciences and aims to ensure the safe and effective use of pharmaceutical drugs. The scope of...