Medical Dosimetrist

Radiation therapy is used to treat malignant cancers by directing an external radiation beam or inserting radioactive seeds or applicators into or near a cancerous tumor. Radiation therapy can help destroy the cancer by killing tumor cells, but it also can damage healthy cells, tissues and organs in the process. Radiation treatment can require one dose or several treatments scheduled over days or weeks.

The medical dosimetrist is a part of the radiation oncology team, which includes a radiation oncologist, medical physicist, radiation therapists and oncology nurses.

Medical dosimetrists ensure that radiation treatment promotes the most lethal radiation dose with the fewest side effects to the patient’s healthy organs.

When a radiation oncologist prescribes radiation to a tumor, a medical dosimetrist creates a plan to deliver the prescribed radiation dose. The medical dosimetrist uses a computer with three-dimensional imaging software to contour normal organs on a treatment planning CT scan. Image fusion of a diagnostic CT, PET/CT or MRI may also be used to help assist the radiation oncologist in determining where the tumor is located. The medical dosimetrist then creates a 3D-conformal or intensity modulated radiation therapy plan and determines an arrangement of beams to deliver the radiation to the tumor, while minimizing damage to normal organs. Physics calculations are done and the medical dosimetrist and radiation oncologist evaluate the dose to the tumor and organs at risk.

Once the radiation oncologist approves the course of treatment, the medical dosimetrist will prepare the plan for treatment and make sure the plan will work as designed. The medical dosimetrist communicates with the radiation therapists in implementing the treatment plan.

In addition to planning radiation treatment, Medical Dosimetrists may assist in quality assurance procedures alongside medical physicists, educate medical dosimetry students and/or work on research teams to help improve the effectiveness of radiation therapies.

It is important for medical dosimetrists to have good listening and communication skills. The medical dosimetrist must first listen carefully to the radiation oncologist to understand the treatment goals, accurately document the treatment plan and then explain it to the radiation therapist responsible for the plan’s implementation. Medical dosimetrists must also have excellent computer skills and be good at problem solving.