Scope of Practice

As health care delivery systems and technology continue to evolve, the role and responsibilities of the medical dosimetrist requires delineation. The Scope of Practice is designed to define the practice of medical dosimetry; identify proficiency in medical dosimetry practice; and provide a useful guide for medical dosimetrists and others to evaluate the quality, effectiveness and appropriateness of health care services.

The initial Statement of the Scope and Standards of Medical Dosimetry Practice was developed under the auspices of the Medical Dosimetrist Certification Board (MDCB) in 1996 by the Medical Dosimetrist Scope of Practice Research Committee. It was most recently revised by the American Association of Medical Dosimetrists (AAMD) in May 2023 as The Scope of Practice of a Medical Dosimetrist.

The Scope of Practice of a Medical Dosimetrist can be viewed at

Joint Statement of the AAMD and MDCB Regarding Scope of Practice

The Medical Dosimetrist Certification Board (MDCB) 2016 Certified Medical Dosimetrist (CMD) Survey indicated that many medical dosimetrists are being asked to contour clinical target volumes (CTVs) and gross target volumes (GTVs).1  Medical dosimetrists should be aware that requests to determine CTVs and GTVs are outside the scope of practice for medical dosimetrists. Further, the medical dosimetrist who is certified and submits to requests to execute contours of CTVs and GTVs is in violation of MDCB Ethical Standard 12,2 “A CMD shall not practice beyond the scope he or she is competent to perform as defined in” American Association of Medical Dosimetrists’ The Scope of Practice of a Medical Dosimetrist.

The literature regarding scope of practice is definitive. Both ASTRO publications, Safety is no Accident3 and the APEX Practice Standards,4 indicate that the role of each member of the Radiation Oncology Practice is delineated by the individual profession’s scope of practice.  Other publications are clear on the specific contouring function. Determining CTVs and GTVs are the responsibility of the radiation oncologist.5

Most health-care professions develop a scope of practice document to define the procedures, actions and processes that a health-care practitioner is permitted to undertake.  The scope of practice endeavors to assure proficient performance that reflects ongoing professional training. For those dedicated to the ever more complex radiation oncology field, safe and competent delivery of care is achieved through adherence to the guidelines outlined. Medical dosimetrists must not practice beyond the boundaries outlined in The Scope of Practice of a Medical Dosimetrist.

Finally, members of a  radiation oncology team should recognize the obligation to voice concerns regarding patient care and safety without fear of reprimand.6 No matter how small a facility the ultimate concern is delivering  safe patient care.7



3, 5, 6, 7 Albert Blumberg, e. a. (2012). Safety is No Accident. ASTRO.

4 ASTRO. (2014). APEx Program Standards. Arlington: ASTRO.

Safety Is No Accident

ACR-ASTRO Practice Parameters