Ready to sit for the Medical Physics for Radiation Oncology and Radiation and Cancer Biology parts of the ABR Qualifying Exam? Here is what to expect on your test day.
These two computer-based remote exams form key portions of the ABR Radiation Oncology Qualifying Exam, distinct from the Clinical Radiation Oncology part and the later oral Certifying Exam. Together they assess your foundational knowledge in medical physics as applied to radiation oncology and the principles of radiation and cancer biology. You can take them together on the same day or schedule them separately. The ABR typically offers both exams annually in June, with results generally posted in myABR within about a month. Review the technical requirements and rules below carefully before your exam date.
Both exams are administered remotely after you register through myABR. Before test day, complete the Exam Readiness Check and Monitor Performance Self-Check on the exact computer and in the exact location you plan to use for testing.
Basic requirements include:
You are fully responsible for confirming your setup meets these requirements ahead of time. ABR staff cannot provide individual technical support for personal equipment on exam day.
Each part, whether Medical Physics or Radiation and Cancer Biology, takes approximately 2.5 hours and is delivered in a single session. If you are taking both on the same day, they run as two separate sessions with a required 60-minute intermission between them.
Permitted:
Prohibited:
Within each session, you control when and how many breaks you take, though content is locked after a break until you resume. Exceeding your allotted break time reduces the time remaining for the exam itself. If you are taking both exams on the same day, the intermission between sessions is a mandatory 60-minute break, and you cannot start the second session early. Keep your webcam on and your connection active during breaks, though you are permitted to leave the room.
On exam day, you will complete an identification check (photo ID plus a selfie) along with a technical verification before the exam begins. Follow all on-screen prompts and confirmations carefully before starting.
Knowing the exam logistics is only half the battle. Grounding your review in the official ABR study guides and high-yield principles across each domain matters more than last-minute cramming.
Approximate domain weighting for guidance:
| Basic physics | 11–13% |
| Radiation measurements | 9–11% |
| Treatment planning | 19–21% |
| Imaging modalities and applications in radiotherapy | 16–18% |
| Brachytherapy | 12–14% |
| Advanced treatment planning and special procedures | 15–17% |
| Safety, QA, and radiation protection | 11–13% |
Approximate domain weighting for guidance:
| Interaction of radiation with matter | 1–4% |
| Molecular and cellular damage and repair | 13–17% |
| Cellular response to radiation | 7–10% |
| Linear energy transfer (LET) and oxygen effect | 3–5% |
| Tumor biology and microenvironment | 3–5% |
| Cancer biology | 19–23% |
| Radiobiology of normal tissues | 9–12% |
| Dose delivery | 11–15% |
| Combined modality therapy | 11–15% |
| Late effects and radiation protection | 6–9% |
Because treatment planning and imaging carry the heaviest weight on the physics side, and cancer biology carries the heaviest weight on the biology side, a study plan that gives those domains proportionally more time, while still covering every topic, tends to pay off. Build familiarity with core concepts, equations, and their clinical applications rather than memorizing in isolation, and complete the Exam Readiness Check with sample questions ahead of time so the interface itself is not a source of surprise. Official ABR study guides, ASTRO resources, and consistent question practice are all worth building into your routine.
Build familiarity with high-yield physics and radiobiology questions and evidence-based rationales before test day.
Practice on irrad8u.com ✦irrad8u.com offers a free, continuously growing radiation oncology question bank built specifically for TXIT, ABR written boards, including Physics and Biology Qualifying Exam preparation, and MOC.
Good luck on your Physics and Biology Qualifying Exams.