Biodistribution and Safety of the PET Probes [18F]FPRGD2 and [18F]FPPRGD2

Early Phase 1CompletedNCT01383135

Stanford University27 enrolled

Overview

The purpose of the study was to conduct a pilot test of new tracers (\[18F\]FPRGD2 and \[18F\]FPPRGD2) to define normal tracer biodistribution (where the tracer goes), stability (how much metabolises), pharmacokinetics (how much stays in which organs and for how long), and radiation dosimetry (organ radiation dose). Healthy volunteers provided the normal biodistribution data. The same radiopharmaceutical was also tested in breast cancer, glioblastoma multiform (brain cancer), and lung cancer.

The tracer \[18F\]FPRGD2 was not evaluated in this study. The protocol title was never amended to reflect this.

Study Type

INTERVENTIONAL

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Enrollment

Conditions

Breast Cancer Non-Small-Cell Lung Cancer Glioblastoma Other Cancers

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: Healthy volunteers: 1. Must be 18 years of age or older. 2. Must have no known medical problems and have had a full medical exam within 6 months of the study. 3. Must understand and voluntarily have signed an Informed Consent after its contents have been fully explained. 4. Women of child bearing potential (as defined as women who are not post menopausal for 12 months or who have had no previous surgical sterilization). 5. Men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation and for 30 days after the last dose. Cancer subjects: 1. Greater than 18 years-old at the time of radiotracer administration 2. Provides written informed consent 3. Diagnosed with advanced non-small cell lung cancer (NSCLC), breast cancer, pancreatic cancer and glioblastoma multiforme (GBM); patients will undergo bevacizumab or Cyberknife therapy 4. Able to remain still for duration of each imaging procedure (about one hour) Exclusion Criteria 1. Less than 18 years-old at the time of radiotracer administration 2. Pregnant or nursing

Outcomes

Primary Outcomes

Tracer Dosimetry by Organ

Normal radiopharmaceutical biodistribution was analyzed visually to obtain dosimetry data in healthy volunteers. Organs with the highest radiation absorbed dose (dosimetry) are provided below. Dosimetry was calculated by drawing regions-of-interest around organs with visually appreciable radiopharmaceutical uptake greater than background and using organ-level internal dose assessment software from Vanderbuilt University (2003). Results are reported in mSv/MBq (milli-Sieverts per mega-Bequerel) which is a measurement of the mean absorbed radiation dose within an organ.

Time frame: 5 hours

F18-FPPRGD2 Time-activity at Specified Timepoints

Radiopharmaceutical pharmacokinetics describe the change in radiopharmaceutical distribution in the body (from the blood to organs, tissues, cells) over time. Radiopharmaceutical pharmacokinetics are used to determine optimal imaging time, ie, when target activity (organ or cell of interest) is greater than background activity (blood). Optimal imaging time must also be balanced with tracer bio-metabolism and radioactive decay. F18-FPPRGD2 pharmacokinetics was measured in healthy volunteers to estimate optimal imaging time. Scans were used to visually identify regions of interest (organs of F18-FPPRGD2 accumulation), and detected radiation was plotted as a measurement over time.

Time frame: 30, 60, and 90 minutes post-injection

Sensitivity of F18-FPPRGD2 PET/CT in Breast Cancer

Sensitivity is the ability of a test to correctly identify patients with the disease being investigated. In this instance, how well F18-FPPRGD2 PET/CT detects true-positive patients. Sensitivity is defined as \[TP/ (TP+FN)\], where TP= true positive, and FN = false negative. The outcome is reported as a percentage without dispersion. A higher percentage indicates a greater probability that a lesion identified based on scan results is cancerous, and a lower percentage indicates reduced confidence in that result.

Time frame: 3 hours

Specificity of F18 FPPRGD2 PET/CT in Breast Cancer

Specificity is the ability of a test to correctly identify patients who do not have the disease being investigated. In this instance, how well F18 FPPRGD2 PET/CT detects true-negative patients. Specificity is: \[TN/ (TN+FP)\], where TN= true negative, and FP = false positive.

Time frame: an estimated average of 3 hours

Glioblastoma Primary Tumor Response Assessed by PET Scan

Primary tumor response was assessed after 6 weeks of treatment as the change in tumor metabolism based on the maximum standardized uptake value (SUVmax) as determined by positron emission tomography (PET) scans. Decreased SUVmax correlates to a reduction of tumor metabolism, and is considered an indicator of primary tumor response. Reduction of SUVmax was determined as the change from baseline in uptake of F-18FPPRGD2. The outcome is reported as the baseline and week 6 values, with standard deviation.

Time frame: Baseline and Week 6

Secondary Outcomes

Glioblastoma Primary Tumor Response Assessed by CT Scan

Primary tumor response was assessed after 6 weeks of treatment as the change in tumor metabolism based on the maximum standardized uptake value (SUVmax) as determined by computed tomography (CT) scans. Decreased SUVmax correlates to a reduction of tumor metabolism, and is considered an indicator of primary tumor response. Reduction of SUVmax was determined as the change from baseline in uptake of F-18FPPRGD2. The outcome is reported as the mean difference from baseline to week 6, with standard deviation.