Under the general supervision of the Chief Dosimetrist, the Clinical Chief Physicist, and the Director-Radiation Oncology Operations, the Medical Dosimetrist develops optimal treatment plans for cancer patients that maximize the dose to the tumor while minimizing dose to normal organs under the direction of the radiation oncologist. Also provides support and assistance for other activities related to patient care, staff and student (radiology oncology residents) education. Dosimetrists are members of a radiation oncology treatment team that plays a key role in the management of cancer. They use their knowledge of mathematics, medical physics, science, and critical thinking to measure and generate radiation dose distributions and calculations for patients and are thoroughly familiar with the physical and geometric characteristics of the radiation equipment and radioactive sources commonly employed. Dosimetrists are responsible for designing a treatment plan and carrying out calculations with mathematical accuracy for the delivery of radiation treatment based on the radiation oncologist's prescribed course of radiation therapy. This treatment plan takes into consideration tumor pathology, tumor volume, and inherent dose-limiting structures surrounding the tumor. The treatment plan and radiation field-placement techniques are constructed utilizing sophisticated computer equipment and technology. The Dosimetrist, along with the Radiation Oncologist and Medical Physicist, will work to construct a treatment plan that will meet the prescription written by the oncologist, ensuring that the patient will not lose important healthy organ function and that the radiation delivered will not affect healthy surrounding tissue. These treatment plans not only include the use of radiation, but in many cases, involve the use of radioactive elements during interstitial brachytherapy procedures. Once the treatment plan is complete, the Dosimetrist will work closely with the radiation therapists in the implementation of the prescribed plan. The Dosimetrist also advises the radiation therapists during simulation and treatment on optimal patient immobilization and setup reproducibility as well as the correct use of devices and field arrangements.