Positron Emission Tomography - Computed Tomography (PET-CT) Cetuximab Project

Inclusion Criteria: * Histologically or cytologically proven colorectal cancer * Unresectable stage IV disease * K-Ras wild type tumour * Patients scheduled to undergo chemotherapy with irinotecan and cetuximab Exclusion Criteria: * Prior abdominal/pelvic radiotherapy, surgery or chemotherapy within 3 months prior to inclusion in the study * Poorly controlled diabetes * Concomitant serious illness, such as uncontrolled angina pectoris, myocardial infarction, heart failure, uncontrolled hypertension, infection * Symptomatic brain metastases * Pregnancy or participants of reproductive potential who are sexually active and not willing/able to use medically appropriate contraception