Positron Emission Tomography Imaging With [F-18] FLT Compared to [F-18] FDG in Cancer Patients for Treatment Evaluation

Inclusion Criteria: 1. Patient provides written Informed Consent and is willing to comply with protocol requirements 2. Patient is at least 18 years of age on the day of dosing (male or female of any race or ethnicity) 3. Patient is capable of lying still in the PET scanner for the protocol required time frame(s) 4. Patient has a diagnosis of one of the following malignancies (TNM Staging System): * Lung cancer (T3 grade up, node positive, but no metastatic disease) * Head and neck cancer (T3 grade up, node positive, but no metastatic disease) 5. Patient has undergone a comparative, diagnostic procedure with lesion(s) visible, other than ultrasound, that includes, but is not limited to computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine imaging, endoscopy, laparoscopy, standard abdominal x-ray, biopsy and/or surgery for one of the above mentioned areas 6. Patient is scheduled to start radiotherapy or a chemoradiotherapy regimen for curative intent 7. As a part of his/her standard radiotherapy or chemoradiotherapy regimen, patient is scheduled to have clinical \[F-18\] FDG PET scans pre treatment and post treatment (at about 4 weeks (±1 week) after the start of therapy) 8. Patient is scheduled to have the investigational, pre treatment \[F-18\] FLT PET scan recommended to be within ± 2 days of the clinical, pre treatment \[F-18\] FDG PET scan 9. Patient has not received or intends to receive 5-fluorouracil (5-FU-chemotherapeutic agent) 10. Patient has a score of greater than or equal to (≥) 60% on the Karnofsky Performance Status Scale Exclusion Criteria: Exclude a patient from this study if the patient does not fulfill the inclusion criteria, or if any of the following conditions are observed: 1. Patient is a pregnant or lactating female. These methods will be used to exclude the possibility of pregnancy: * by testing on site at the institution (serum or urine βHCG) within 48 hours prior to the start of each investigational product administration, * by surgical history (eg, tubal ligation or hysterectomy), * by patient's history of being post menopausal with a minimum 1 year without menses. 2. Patient is undergoing treatment with palliative intent 3. Patient has received an investigational compound and/or medical device within 14 days before admission into this study 4. Patient has any medical condition or other circumstances which would significantly decrease the chances of obtaining reliable data, achieving study objectives, or completing the study and/or post-dose follow-up examinations 5. Patient is determined by the Investigator that he/she is clinically unsuitable for the study.