The different specialists in the Cancer department may include the following: Radiation Oncologists use radiation therapy to treat cancer. Medical Oncologists use chemotherapeutic agents for cancer treatment. Surgical Oncologists use surgical procedures for cancer treatment and tumor removal. Nuclear Medicine Specialists use small amounts of radioactive isotopes (radionuclides) to diagnose and treat disease for various disease states. Many times, one doctor specializes in more than one condition. You can consult with that specialist, depending on your condition.