Master of Science in Medical Dosimetry

According to the American Association of Medical Dosimetrists (AAMD) at, the Medical Dosimetrist is a member of the radiation oncology team who has knowledge of the overall characteristics and clinical relevance of radiation oncology treatment machines and equipment, is cognizant of procedures commonly used in brachytherapy and has the education and expertise necessary to generate radiation dose distributions and dose calculations in collaboration with the medical physicist and radiation oncologist.

After the Radiation Oncologist has consulted with the patient on their plan of treatment, he/she will write a prescription of radiation dose to a defined tumor volume. The medical dosimetrist will then design a treatment plan by means of computer and/or manual computation to determine a treatment field technique that will deliver that prescribed radiation dose. When designing that plan, also taken into consideration are the dose-limiting structures. These structures could include the eye when treating the brain, the heart when treating the lung, or the spinal cord when it is included in the area of treatment.

The medical dosimetrist maintains a delicate balance between delivering the prescription the physician has written while ensuring the patient will not lose important healthy organ function. In many institutions, the medical dosimetrist also has the ability to execute planning for intracavitary and interstitial brachytherapy procedures.

Following the planning process, the patient will have a simulation for tumor localization to ensure reproducibility of treatment set up and plan delivery. Here, it may be necessary to produce moulds, casts, and other immobilization devices for accurate treatment delivery. A medical dosimetrist may supervise, perform, or assist in this process. The medical dosimetrist will then work with the radiation therapists in the implementation of the patient treatment plans including: the correct application of immobilization devices, beam modification devices, approved field arrangements, and other treatment variables.

The advancements in computer technology places us at the forefront of many new processes. Using imaging modalities such as CT scans, alone or in combination with MRI or PET scans, we plan with 3-D computers that enable us to give higher doses of radiation to a tumor while lowering the doses to the sensitive structures around it. In some environments we play a part in cutting edge clinical research for the development and implementation of new techniques in cancer treatment. It is an exciting and amazing profession to work in. We are members of a team that contributes toward cancer survivorship on a daily basis.

In summation, the medical dosimetrist performs calculations for the accurate delivery of the Radiation Oncologist's prescribed dose, documents pertinent information in the patient record, and verifies the mathematical accuracy of all calculations using a system established by the Medical Physicist. We perform, or assist in, the application of specific methods of radiation measurement including ion chamber, thermoluminescent dosimeters (TLD), or film measurement as directed by the Medical Physicist. Another area that we may contribute to is giving technical and physics support to the Medical Physicist; this support could be in radiation protection, qualitative machine calibrations, and quality assurance of the radiation oncology equipment. Also, we often take on the role of educator in facilities that have radiation oncology residents, radiation therapy students or medical dosimetry students.

Grand Valley State University M.S. in Medical Dosimetry Program

GVSU students receive didactic, laboratory, and clinical experiences in both existing and emerging radiation oncology, including treatment planning, simulation, quality assurance, brachytherapy, external beam therapy, stereotactic radiosurgery, intraoperative radiation therapy, Intensity modulated Radiation Therapy, and total body irradiation.

The GVSU Medical Dosimetry program is in the process of applying for accreditation by the Joint Review committee on Education in Radiologic Technology (JRCERT).  Once the program is accredited by the JRCERT, students who receive a M.S. degree in Medical Dosimetry from Grand Valley are eligible for the Medical Dosimetrist Certification Board (MDCB) national credentialing certification examination in medical dosimetry.  Upon certification by the MDCB, graduates will hold the title of Certified Medical Dosimetrist (CMD).

Individuals who have been involved in a criminal proceeding or charged with or convicted of a crime may not be eligible for national certification by the MDCB. Because this certification is available to graduates of the medical dosimetry program as part of preparation for clinical practice, students to whom this may apply are strongly advised to work with the MDCB for pre-application review of eligibility for certification from their website at The MDCB may be contacted by phone at 856-439-1631 for more information go to

Once the GVSU Medical Dosimetry program is accredited by the JRCERT, the program will adhere to JRCERT standards. Students will have the right to notify the JRCERT if they believe the university is not adhering to these standards. The JRCERT is at 20 N. Wacker Dr., Suite 2850, Chicago, IL 60606-3182, phone 312-704-5300, (