Visit 4: Day of Interim 18F-FLT-PET/CT: The interim 18F FLT-PET/CT will be performed after the 2nd cycle of chemotherapy regimen, but before the commencement of 3rd cycle. The second 18F-FLT-PET/CT study must be performed on the same scanner as the first 18F FLT-PET/CT and the imaging protocol described in Visit 3 should be closely followed.