Dr. Gary T. Smith
University of Tennessee Medical Center
1924 Alcoa Highway
Knoxville, TN 37920
Phone: 423-544-9818 Ext: n/a
Fax: 423-544-8883
Email: smith@scanner.hosp.utk.edu
Projects are approved by an IRB located at: University of Tennessee Medical Center-Knoxville.
The approving IRB operates under a Multiple Project Assurance (MPA) recognized by DOE or by the Department of Health and Human Services (HHS).
MPA number of the IRB: M-1056
Number of Human Subjects Projects reported: 1
Project Identifier: UTMC-92-IRB-0104
Project Title:
A Consortium to Develop the Medical Uses of NMR Imaging, NMR Spectroscopy, and Positron Emission Tomography
Principle Investigator:
Dr. Gary T. Smith
Project started in: 1992
Project Funding Information:
Project received funding in Fiscal Year 1995.
Project did not use human subjects in Fiscal Year 1995.
Explanation:
All patient studies performed prior to fiscal year 1995. Data analysis was performed in 1995.
Funding Sources:
There was no funding associated with human subjects this year.
Project does not involve use of multiple protocols/subprojects.
IRB Review:
Type of Review: Full Board
Most Recent Approval: December 15, 1994
IRB Approval Number: 0104
Number of Human Subjects in the Last Reporting Period for this Project: 11
(Reporting periods vary.)
Type of Human Subjects Involvement:
Internal administration of radioactive substances to human subjects.
This project is designed to quantify skeletal muscle blood flow and metabolism for assessment of ischemia. The ultimate goal is to provide a non-invasive method of measuring viability of skeletal muscle following traumatic vascular compromise. The technique involves the use of both dynamic positron emission tomography (PET) coupled with compartmental model analysis of the resulting time activity relationships and nuclear magnetic resonance spectroscopy (NMRS). PET scanning is ideally suited for this project because of the capability to utilize labelled organic compounds. Blood flow will be measured with N-13 ammonia. Metabolism will be assessed with F-18 deoxyglucose (FDG).
Specific aims of the project include: 1) is there a threshold level of muscle perfusion below which there is no chance of metabolic recovery, 2) can the degree of recovery be assessed by PET measurements of skeletal muscle metabolism, in particular, with FDG and BCAA, 3) can PET be used to assist surgeons in choosing the optimal site for muscle debridement in order to minimize the risk of both infection and recurrent tissue death, and maximize the potential for wound healing, and 4) can NMRS be used either in conjunction with PET scanning or independantly to provide information about the healing potential of skeletal muscle following acute injury.
The study period is divided into two phases. Phase I (one year) was devoted to developing new methods applicable to skeletal muscle physiology utilizing an isolated gracilis muscle canine model. Models for determination of skeletal muscle blood flow (13N ammonia) and both glucose and BCAA metabolism 18F deoxyglucose, 11C-leucine, were investigated for use with dynamic PET scanning. In Phase II (two years), the models are being studied for use in human subjects. Overlap of appropriate portions of the two phases in the early years will provide time for clinical follow-up in the later years.
Methodology: All procedures in this study may be performed on an outpatient basis. A transmission scan is done using an external ring source containing 5 mCi of 68Ge for the purpose of attenaution correction. The patient is given 13NH3 or 18FDG. The average dose will be: 13NH3 - 15mCi and 18FDG - 7.5 mCi. PET imaging of affected tissue begins according to the following schedule: 13NH3: upon completion of transmission scan, 18FDG: 1 hour after comletion of 13NH3 scan. Each scan continues for approximately 20 minutes. Scans are done with a 15 slice machine 931/08 ECAT PET unit. In the 18FDG scans, glucose loading with 50 gm dextrose will be given either IV or PO in all trauma patients. In the diabetic patients, glucose loading will only be employed when the initial blood sugar is below 140 mg/dl. Measurement of blood glucose is obtained in all patients at the time of glucose loading, one hour after oral or IV glucose, and at the end of the study.
Human Subject Involvement: All women of reproductive age have serum HCG analysis for pregnancy prior to the scans. No studies will be performed on patients less than 18 years of age. Each clinical protocol and the use of radioactive tracers has been approved by the UTMCK Human Subject Protection Committee, the Isotope Committee, and the Radiation Protection Committee.
All participants sign a consent form which includes the following: nature of the procedure, potential benefits and risks, and patients right to refuse any stage of the protocol without jeopardizing their care, provision of any or all medical treatment necessary as a result of participation, and names and telephone numbers of investigators or UTMCK officials who can be contacted for questions and concerns. All examination results and patient medical records are kept strictly confidential.
Venous punctures are standard procedures and carry a low risk for complications. The radiation doses to the patient are within the radiation exposure considered acceptable for routine diagnostic and nuclear medicine procedures. The risk of low level radiation is explained to the patient.
Safety precautions at UTMCK are employed according to usual practices within the medical center. The PET facility is equipped with standard acute care materials including a crash cart, cardiac monitors, and automated blood pressure monitoring devices. A board certified nuclear medicine physician and critical care nurse are present during each study to supervise the use of monitoring equipment and the delivery of radioisotopes.
Any information derived from these studies can potentially benefit the patient's acute wound management. Ultimately, data from this study are expected to provide a more practical approach to management of wounds in acute and chronic situations.