Exam Development

How is the Certification Exam Developed?

The MDCB exam has been administered annually since 1988. In order to determine content initially, volunteer subject matter experts identified areas of knowledge and practice for testing, developed appropriate test questions, and assisted with validation of the examination. The exam is delivered in English only and was designed to test the dosimetry knowledge of U.S.-based practitioners. The examination continues to be updated for relevancy to current practice through a Job Analysis Survey conducted every five years by Prometric, the MDCB exam administrator.

The Job Task Analysis also known as a Role Delineation Study is designed to meet stringent certification industry standards and recognized best practice guidelines. An electronic survey examines more than 150 work-related task and knowledge statements, and is distributed to all MDCB certificants and AAMD members totaling approximately 5,000 professionals in the field of Medical Dosimetry. Volunteer content experts use this data to identify areas of knowledge for testing from the content domains identified and write exam questions to target those areas.

A Job Task Analysis was conducted in 2023.  An announcement will be made when the test specifications derived from the 2023 Task Analysis will be employed. 

In accordance with best practices, following the conduct of a Job Task Analysis a Standard Setting Study is performed to determine a passing score. The passing score identifies what the minimally qualified candidate will know. Each candidate’s ability is measured against the determined cut score.

The examination typically contains 155 multiple questions. The time allowed for completion is 3 hours and 50 minutes. The examination is administered in English only. A small percentage of randomly embedded un-scored items are included on the exam to obtain and evaluate statistical information for new items. These items are not included in the score calculation. This practice is consistent with industry standards for a certification exam.

A small number of performance-based test (PBT) questions are included in the CMD exam.  Performance-based questions measure candidates' ability to apply learned skills and knowledge. It is considered to be the next generation in certification testing. The PBT items include both multiple-choice and contouring items. 

References used for MDCB exam item writing include popular textbooks covering subjects in radiobiology, physics, dosimetry, cross-sectional anatomy, and principles of radiation oncology practice such as the following:

  • Gibbons, John, Kahn's the Physics of Radiation Therapy. 6th ed. 2019.
  • Khan, Faiz M. Treatment Planning in Radiation Oncology. 4th ed. 2016.
  • Perez, Carlos A. and Brady, Luther W. Principles and Practice of Radiation Oncology. 6th ed. 2014.
  • Fleckenstein, P.  Anatomy in Diagnostic Imaging, 3rd ed. 2014.

Other popular texts can be found at the AAMD store and Medical Physics Publishing websites.  In addition, item writers draw questions from reports that are relevant to current dosimetry practice published by the AAPM, ABS, ASTRO, ICRU, ICRP and NCRP as well as published RTOG clinical trials and NCCN guidelines.  Because the practice of medical dosimetry and radiation technology evolves rapidly, it is not possible for MDCB to rely solely on textbooks and published reports for up-to-date information in all subject areas.  Dosimetrists are expected to be aware of recent advances in the field and have a general knowledge of topical literature including key journal articles that have impacted the practice.   In addition, dosimetrists should understand recent technological advances in radiation delivery equipment and imaging such as Cyberknife, TomoTherapy, GammaKnife, cone beam CT, etc.

Examples of relevant recent journal articles include the following:

  • QUANTEC Special Issue.  International Journal of Radiation Oncology Biology Physics.  Volume 76, Issue 3, Supplement, S1-S160 March 2010.
  • Otto K.  Volumetric modulated arc therapy:  IMRT in a single arc. Med Phys. 35. 310-317 (2008).