Pseudo-Simultaneous Imaging of Tumor Hypoxia and Proliferation in HNC Patients Using PET/CT

A Pilot Study to Assess the Feasibility of Pseudo-Simultaneous Imaging of Tumor Hypoxia and Proliferation in Head and Neck Cancer Patients Using PET/CT

66% of HNC patients present with advanced-stage disease at initial diagnosis. The 5-year survival rates for stages IVa, IVb, and IVc are 32%, 25%, and <4% respectively. Accurate pre-treatment staging is vital in determining the optimum procedure for the management of HNC. Early identification of non-responders may allow modification of their treatment through the introduction of more intensive therapies. Identifying prognostic factors that predict patient outcome will ultimately lead to new treatment regimens. Tumor hypoxia and proliferation are two key characteristics of cancer that were shown to correlate with poor response to treatment in HNC. In this proposal, the investigators assess the prognostic values of these two markers. Combining information from these two biological markers shall result in prognostic information superior to those of any of the two separately. Imaging those vital tumor characteristics simultaneously shall provide more coherent assessment of tumor microenvironment than does registration of corresponding images acquired in different imaging session, thus subject to uncertainties resulting from transient biologic changes and image registration process. The investigators propose to use a method that the investigators previously developed to simultaneously and non-invasively image tumor hypoxia (FMISO-PET) and proliferation (FLT-PET) within a single PET/CT study. CT Perfusion scan will be performed 1st, followed by PET imaging with staggered FMISO and FLT injections. FMISO and FLT signals will be separated retrospectively using kinetic modeling. The investigators believe imaging tumor hypoxia and cell proliferation simultaneously yield information underpinning for image-guided and radiobiological based dose painting, adaptive therapy, and patient medical management. If successful, this pilot study will constitute the basis for a NIH grant proposal that aims to improve treatment outcome assessment in HNC.

The study includes two arms: Arm1: FLT PET/CT on Day1 and Day2 Arm2: Combined FMISO/FLT PET/CT on Day1 and FLT PET/CT on Day2

Radiotracer: 18F-FLT and 18F-FLT Dose and Frequency: 8 mCi 18F-FLT and 8 mCi 18F-FLT on Day1, the 8mCi 18F-FLT on Day2

To assess the feasibility to tease out the FMISO and FLT kinetics in simultaneous FMISO/FLT PET/CT imaging. FMISO and FLT kinetic parameters will be measured from the combined FMISO/FLT dynamic study. The accuracy of those measurements will be tested by comparing the FLT kinetic measurements deduced from the combined FMISO/FLT study on day1 with those from the sole FLT study of day2.

To assess the repeatability of FLT kinetics. Subjects will undergo two dynamic FLT PET studies up to 3 days apart. The repeatability of the corresponding kinetic parameters from the two studies will be measured using statistical methods (e.g. Bland-Altman analysis)

Subject Inclusion Criteria: Pathologic Confirmation of HNC No prior treatment for this diagnosis of HNC Patient to be treated with Radio-Therapy Age >= 18 years old Karnofsky performance status >= 70% Women of childbearing age must have a negative blood pregnancy test. Exclusion Criteria: Women who are pregnant or breast-feeding. Severe diabetes (fasting blood glucose > 200- mg/dl) Adults who are unable to consent Patients who do not agree to share and store data History of lack of tolerance of the standard of care FDG-PET scan previously obtained History of previous intolerance of either FMISO or FLT.