The most significant difference between cancer cells and normal cells is their tendency to proliferate uncontrollably and rapidly. This high proliferation leads to a much greater consumption of energy and substances than normal. PET/CT imaging technology is based on this metabolic difference. Substances heavily utilized by cancer cells, such as sugars, proteins, and certain special building blocks, are radioactively labeled. When these labeled substances are administered into the body, they are absorbed more by cancerous tissues exhibiting high metabolic activity and are precisely visualized by a PET scan. The PET/CT device helps in diagnosis by detecting the location and activity of cancerous tissues through this method.