PET Imaging With Tc-94m Sestamibi to Assess Resistance to Chemotherapy
Condition: Cancer
Intervention: Tariquidar; Tc-94m Sestamibi
Intervention description: 3 days after initial PET patients will receive tariquidar and repeat imaging.; Patients over 18 years of age, who are eligible for, or have completed enrollment in an active NCI (National Cancer Institute) protocol for treatment of cancer will undergo a PET sestamibi scan
Phase: Phase 2
Study type: Interventional
Primary purpose: Diagnostic
Intervention model: Single Group Assignment
Masking: None (Open Label)
Enrollment: 12.0
Sex: All
Minimum age: 18 Years
Maximum age: 65 Years
Healthy volunteers: No
Keywords: Tariquidar; PET; Sestamibi; Cancer

Summary:

      Background:

        -  Tc-94m sestamibi is a radioactive imaging drug approved by the Food and Drug
           Administration to help photograph and study bodily functions.

        -  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.

      Objectives:

      -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.

      Eligibility:

      -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.

      Design:

        -  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 (positron emission tomography) 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.
    

Eligibility criteria:

        -  INCLUSION CRITERIA:

        Patients must be eligible for enrollment in an active NCI (National Cancer Institute)
        protocol for treatment of cancer.

        Patients greater than or equal to 18 years old.

        Performance Status ECOG (Eastern Cooperative Oncology Group) 0 - 2.

        Patients must be able to give informed consent.

        Women of childbearing potential must have a negative pregnancy test within 24 hrs of Tc-94m
        injection.

        Patients who have previously received tariquidar will be eligible, since no study has
        systematically shown loss of MDR-1 (Multi Drug Resistance Protein 1)/Pgp expression in
        tumors following exposure to both tariquidar and an anticancer agent.

        An index lesion greater than 1.5 cm will be required to optimize the PET (positron emission
        imaging) images.

        EXCLUSION CRITERIA:

        Patients who are pregnant or breast-feeding will not be enrolled in order to prevent
        radiation exposure in the developing fetus or infant.

        Patients weighing greater than 136 kg (the weight limit for the scanner table).

        Patients having only tumor sizes less than 1.5 cm will be excluded.

        HIV (human immunodeficiency virus) positive patients will be excluded to prevent potential
        drug interactions between tariquidar and antiretroviral agents.