CMD Cheat Sheet 2026

The 30 highest-yield CMD facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. For lung cancer radiotherapy, what is a key pulmonary dose-volume constraint used to predict radiation pneumonitis risk? → Mean lung dose (MLD) ≤ 20 Gy
2. Which of the following is a component of quality assurance in radiation therapy? → Routine maintenance and calibration of equipment
3. Which quality improvement method is most applicable to quality assurance & performance improvement in Certified Medical Dosimetrist? → Plan-Do-Check-Act (PDCA) continuous improvement cycle
4. Which staging system is most commonly used for lung cancer to define target volumes in radiation therapy planning? → AJCC TNM staging
5. When using respiratory gating for lung SBRT, the treatment beam is delivered during: → A defined phase or amplitude range of the respiratory cycle
6. What is the unit of absorbed dose in the SI system used in radiation therapy dosimetry? → Gray (Gy)
7. What is the primary purpose of a dosimeter in radiation safety? → To measure radiation dose received by personnel
8. Which physical process is dominant for photon interactions in tissue at megavoltage energies used in radiation therapy? → Compton scattering
9. In the linear-quadratic (LQ) model, the α/β ratio for late-responding normal tissues is typically: → 2–3 Gy
10. How does continuing education relate to evidence-based practice & research methods for CMD certified professionals? → It ensures professionals stay current with evolving standards and best practices
11. How does continuing education relate to professional ethics & legal compliance for CMD certified professionals? → It ensures professionals stay current with evolving standards and best practices
12. Tissue weighting factors (wT) in radiation protection are used to calculate: → Effective dose
13. What is the primary purpose of communication & interprofessional collaboration in the context of Certified Medical Dosimetrist? → To ensure consistent quality and professional accountability
14. Why is patient confidentiality critical in radiation therapy? → To maintain patient trust and meet legal requirements
15. Which imaging modality is most commonly used for radiation therapy simulation and treatment planning due to its electron density information? → CT (Computed Tomography)
16. What ethical consideration is most relevant to evidence-based practice & research methods in CMD practice? → Maintaining confidentiality and acting in the best interest of stakeholders
17. Why are a patient's arms positioned above the head during CT simulation for breast cancer treatment? → To move the arms and shoulders out of the planned tangential beam paths
18. How should a CMD professional handle a situation where quality assurance & performance improvement protocols conflict with practical constraints? → Document the conflict and seek guidance from appropriate authorities
19. In rectal cancer radiotherapy, which structure must be particularly protected to minimize the risk of small bowel toxicity? → Small bowel (loops within the pelvis)
20. What is the purpose of routine calibration in radiation therapy? → To maintain equipment performance and accuracy
21. Which factor is most critical in determining the radiation dose distribution in a treatment plan? → The tumor's size, location, and surrounding tissues
22. The oxygen enhancement ratio (OER) is highest for which type of radiation? → Low-LET radiation (X-rays, gamma rays)
23. What is the most common beam arrangement for treating a right-sided breast cancer with standard tangential fields? → Medial and lateral tangents to minimize lung dose
24. Which imaging technique is commonly used to assist in treatment planning for radiation therapy? → CT scans
25. Which documentation practice is most important for professional ethics & legal compliance in the CMD field? → Maintaining complete, accurate, and timely records
26. For lung SBRT, the concept of 'dose gradient outside the PTV' is particularly important because: → Rapid dose falloff outside the PTV protects surrounding normal lung tissue
27. What is the primary purpose of quality assurance & performance improvement in the context of Certified Medical Dosimetrist? → To ensure consistent quality and professional accountability
28. Which radiobiological model is most commonly used in clinical dosimetry to compare different fractionation schedules? → Linear-Quadratic (LQ) model
29. What is a common challenge professionals face when applying evidence-based practice & research methods principles in Certified Medical Dosimetrist? → Balancing theoretical knowledge with practical application
30. What is the significance of peer review in evidence-based practice & research methods for CMD professionals? → It promotes accountability, knowledge sharing, and quality improvement