Oncology is the branch of medicine that researches, identifies and treats cancer. A physician who works in the field of oncology is an oncologist.
Oncologists must first diagnose a cancer, which is usually carried out via biopsy, endoscopy, X-ray, CT scanning, MRI, PET scanning, ultrasound or other radiological methods. Nuclear medicine can also be used to diagnose cancer, as can blood tests or tumor markers. Oncology is often linked with hematology, which is the branch of medicine that deals with blood and blood-related disorders.