Positron Emission Tomography is a functional imaging modality that allows the measurement of metabolic reactions within the whole body. Plain film radiographs, CT scan and MRI scan are able to provide good soft and hard tissue imaging only when morphological change have occurred. Nuclear scanning in contrast can help in diagnosis by detecting metabolic changes earlier than they can be seen as morphological changes. PET scan with its widespread applications has emerged as an indispensable tool in the detection, staging, treatment monitoring, and identification of recurrent disease in a large number of malignancies.