The expression oncology signifies a branch of medical sciences that deals with cancers and tumors. The term "onco" signifies mass, mass, or tumor while "-logy" means study. The diagnostic tool is still the patient's history. Frequent symptoms which stage towards cancer include tiredness, weight loss, unexplained anemia, fever of unknown source etc. Oncology depends on diagnostic tools including endoscopy such as the gastrointestinal tract, imaging research such as X-rays, CT scanning, MRI scan, ultrasound and other radiological methods, Scintigraphy, Single Photon Emission Computed Tomography, Positron emission tomography and nuclear medicine techniques etc.