Positron Emission Tomography/Computed Tomography Scanning Before Surgery in Patients With Non-Small Cell Lung Cancer, Colorectal Cancer, Breast Cancer, Esophageal Cancer, or Head and Neck Cancer

RATIONALE: Diagnostic procedures, such as positron emission tomography/computed tomography (PET/CT) scanning before surgery, may help measure the extent of disease.
PURPOSE: This clinical trial is studying PET/CT scanning before surgery in patients with non-small cell lung cancer, colorectal cancer, breast cancer, esophageal cancer, or head and neck cancer.