T exam guide
About the Radiation Therapy (T) exam
The ARRT Radiation Therapy examination assesses patient care, radiation physics and safety, treatment planning, simulation, localization, dose delivery, verification, and site-specific oncology. Preparation should connect the prescription and treatment plan to accurate setup, image guidance, dose, tissue response, toxicity, quality assurance, and compassionate longitudinal care.
MedPorium is an independent education platform and is not affiliated with or endorsed by The American Registry of Radiologic Technologists (ARRT). Exam details can change; confirm them with the official source before applying.
T exam format at a glance
- Questions
- 230
- 200 scored; 30 unscored
- Time
- 230 minutes of test time within a 250-minute appointment
- Delivery
- Computer-based testing at Pearson VUE test centers
Knowledge to review for the T exam
These foundations support the practical tasks in the official examination matrix.
Oncology patient care
- Cancer biology, staging, diagnostics, treatment modalities, records, consent, communication, psychosocial needs, nutrition, skin, pain, and emergencies
- Acute and late tissue effects, site-specific toxicity, medications, infection control, monitoring, supportive care, and patient education
Radiation physics and safety
- Atomic and radiation physics, interactions, beam production, megavoltage equipment, brachytherapy, dose measurement, units, and calculations
- Radiobiology, protection, shielding, monitoring, regulations, QA, treatment incidents, and emergency procedures
Planning and treatment delivery
- Immobilization, simulation, CT data, contours, coordinates, localization, field design, wedges, bolus, blocks, MLCs, isocenter, and plan evaluation
- 3D conformal, IMRT, VMAT, IGRT, stereotactic, electron, proton, brachytherapy, motion management, verification, and site-specific treatment
T examination matrix
The percentages below are the approximate exam-score weights published by The American Registry of Radiologic Technologists (ARRT). Use them to allocate study time, then adjust for your own weak areas.
23%
Patient Care
Assess, educate, position, monitor, and support oncology patients across the treatment course.
- Relate diagnosis, stage, prescription, multimodality care, history, laboratory data, and performance status to treatment
- Prevent, assess, and manage acute and late effects involving skin, mucosa, GI, GU, marrow, lung, CNS, nutrition, pain, and fatigue
- Provide safe psychosocial, infection-control, emergency, medication, documentation, and end-of-treatment care
25.5%
Safety
Apply radiation physics, radiobiology, protection, equipment, dosimetry, calculations, quality assurance, and incident response.
- Relate radiation production and interactions to beam energy, depth dose, scatter, modifiers, and measurement
- Perform or interpret monitor-unit, dose, inverse-square, decay, and related calculations
- Apply personnel and patient protection, machine and treatment QA, verification, time-out, error reporting, and emergency procedures
51.5%
Procedures
The largest area covers simulation, planning, localization, treatment techniques, image guidance, delivery, verification, and site-specific practice.
- Create reproducible immobilization and simulation setups and acquire planning data
- Interpret plans, contours, isodose, DVHs, coordinates, field shaping, accessories, and prescriptions
- Deliver and verify external-beam, electron, IMRT, VMAT, stereotactic, proton, brachytherapy, and motion-managed treatments
How to use this T diagnostic
The diagnostic samples the three currently effective areas. Review each miss as patient assessment or symptom care, physics and protection, treatment planning or dosimetry, localization and simulation, machine and QA, site-specific technique, verification, or error prevention.
High-yield T study priorities
Priority 1
Follow the treatment chain
Trace prescription, simulation, planning, transfer, setup, imaging, verification, delivery, record, and review to locate potential errors.
Priority 2
Calculate before memorizing
Work dose, monitor-unit, inverse-square, decay, equivalence, geometry, and treatment-time problems with units and reasonableness checks.
Priority 3
Compare techniques by tradeoff
For each modality, know indication, immobilization, imaging, motion control, dose distribution, normal-tissue risk, QA, and failure modes.
Priority 4
Use site-specific care plans
Connect anatomy, target, setup, organ-at-risk constraints, expected toxicity, education, monitoring, and urgent findings for each disease site.
T exam FAQ
How many questions are on the ARRT Radiation Therapy examination?
The current examination format contains 230 questions: 200 scored questions and 30 unscored pilot questions. Pilot questions are mixed into the examination and are not identified.
How long is the Radiation Therapy examination?
230 minutes of test time within a 250-minute appointment. ARRT's appointment time also includes the tutorial, nondisclosure agreement, and survey where applicable.
How is the content outline weighted?
The currently effective specification is approximately Patient Care 23%, Safety 25.5%, Procedures 51.5%. These percentages are calculated from ARRT's scored-item counts, so rounding may prevent the displayed values from totaling exactly 100%.
What should I prioritize for Radiation Therapy?
Procedures is the largest scored content area at approximately 51.5%. Give it the largest share of practice, but continue sampling every area because the examination blueprint is broad.
What score is required to pass an ARRT examination?
ARRT reports examination results on a scaled score from 1 to 99, and a scaled score of 75 is required to pass. A 75 scaled score is not the same as answering 75% of questions correctly.
Does this diagnostic predict whether I will pass?
No. A 15-question diagnostic is a low-confidence baseline, not a validated pass prediction. Review every rationale and use larger mixed and content-specific sets to build a more stable readiness estimate.
Is MedPorium affiliated with ARRT?
No. MedPorium is an independent education platform and is not affiliated with or endorsed by The American Registry of Radiologic Technologists.
Review and official source
Clinical reviewer: P. L. Burn
Exam format and matrix information were checked against the ARRT Radiation Therapy credential page and examination content specifications. Source reviewed October 15, 2026.
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