What does a Medical Dosimetrist do?

A medical dosimetrist is an allied health professional that designs radiation treatment plans, calculates dosages for medical radiation and operates radiation equipment. An allied health professional is one that works in the medical field but does not have a medical license. Still, these positions are essential to keeping a healthcare system running smoothly. Other allied health careers include midwifery, optometry and clinical psychology.

After a cancer patient has received a radiation prescription, they will then see a medical dosimetrist. Based on the prescription, the dosimetrist designs a course of treatment using computer or manual calculations. Radiation therapy has serious side effects in humans, including loss of essential organ function and death. The dosimetrist must balance delivering the correct prescription and limiting the negative side effects on the patient.

A dosimetrist works closely with the other members of the radiation oncology team, including the radiation oncologist, the medical physicist and the radiation therapist. For example, the dosimetrist might develop the computerized plans with aid of the medical physicist. Then she may have these plans approved by the radiation oncologist. She may eventually supervise a radiation therapist or radiation technician to have the plans implemented.

Dosimetrists must have a knowledge and understanding of physics and math as well as anatomy and physiology. They must also understand radiobiology and the psychology of cancer. Even though they may not be the ones operating the radiation treatment machinery, they must have advanced knowledge of the radiation equipment and be able to troubleshoot any problems. Good communication skills and analytical skills are also important to the dosimetrist.

The requirements to become a medical dosimetrist are different in each country. In the United States, most common route is to receive a bachelor’s or master’s degree in Medical Dosimetry. Another way is to obtain a Bachelor’s Degree in Medical Radiation Sciences and become licensed as a radiation therapist. The therapist will then work in that field being trained by a medical dosimetrist until they have gained enough on-the-job experience to qualify for the position themselves. The process to enter both formal and informal training programs is very competitive.

Only those who want to be certified have to take and pass the Certified Medical Dosimetrist (CMD) exam given by the Medical Dosimetrist Certification Board. A dosimetrist does not have to be certified to legally practice in the United States. There are some cancer treatment centers that do require a certification for employment. Proposed future legislation may change the certification laws for this field.

It should be noted that in some countries, a medical dosimetrist and a radiation therapist are interchangeable positions. In the United States, the dosimetrist generally has more education and hands-on training. While the duties of these professions often overlap, in larger institutions a dosimetrist may be responsible for the training and supervision of several radiation therapists working with a large pool of patients. In smaller institutions, there may only be one or two dosimetrists and no radiation therapists working with the patients.