ARRT Radiation Therapy Exam Guide 2026: Pass the 200-Item Board (FREE)

The ARRT Radiation Therapy Credential Is Your License to Treat Cancer — Here's How to Pass It in 2026

The ARRT (American Registry of Radiologic Technologists) Radiation Therapy certification and registration exam is the national standard that every entry-level radiation therapist in the U.S. must pass before stepping into a linac vault and delivering a fractionated dose to a cancer patient. Every state that licenses radiation therapists — and every employer that hires them — accepts the ARRT R.T.(T) credential as proof of competence.

In 2026 the exam is a computer-based, 200-item board delivered at Pearson VUE test centers over a 3.5-hour appointment. You need a scaled score of 75 (on ARRT's 1–99 scale) to pass. Eligibility hinges on graduating from a JRCERT-accredited radiation therapy program and clearing the ARRT Ethics Review.

This guide walks you through the verified 2026 structure, the five content categories with current percentages, per-category deep dives (treatment planning, simulation, IMRT/VMAT, brachytherapy, TBI, dosimetry, patient care, anatomy), the $200 application fee, recertification (biennial CE plus the 10-year CQR), a realistic 12-week plan, and the free and paid resources that actually move your score. Everything is free on OpenExamPrep.

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Start Your FREE Radiation Therapy Board Prep Today

Start FREE ARRT Radiation Therapy Practice QuestionsPractice questions with detailed explanations

Category-by-category drills across Patient Care, Safety, Image Production and Treatment Verification, Procedures, and Treatment Sciences — plus dosimetry calculations, IMRT/VMAT QA scenarios, brachytherapy source decay, and TBI setup items. 100% free, no credit card.

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ARRT Radiation Therapy Exam At a Glance (2026)

All figures verified against the official ARRT Radiation Therapy Content Specifications and Handbook at arrt.org. Double-check fees before you apply — ARRT periodically adjusts application pricing.

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What the R.T.(T) Is — and Why It Matters

The R.T.(T) — Registered Technologist (Therapy) — is the ARRT certification that signals you can:

1. Simulate a patient for radiation treatment (CT-sim, 4D-CT, MR-sim, PET-sim)
2. Deliver external beam treatments on linear accelerators (3D-CRT, IMRT, VMAT, SBRT, SRS, electrons, protons)
3. Assist with brachytherapy (HDR, LDR, permanent implants) and specialized techniques (TBI, TSEI)
4. Verify treatment setup through image guidance (CBCT, kV/MV portal, surface guidance, fiducials)
5. Monitor the patient clinically during a typical 4–8 week fractionated course and escalate acute toxicities to the radiation oncologist
6. Practice within the ARRT Standards of Ethics, ASRT scope of practice, and state licensure rules

The R.T.(T) is the national gatekeeper — every state that regulates radiation therapists defers to ARRT certification, and every major cancer center (MD Anderson, Memorial Sloan Kettering, Dana-Farber, Mayo Clinic, Cleveland Clinic) requires it as a condition of employment.

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Eligibility: JRCERT Accreditation and the ARRT Ethics Review

Educational Requirement

ARRT accepts candidates from JRCERT (Joint Review Committee on Education in Radiologic Technology) accredited radiation therapy programs only. Two pathways are common:

Post-primary pathway: An R.T.(R) (radiographer) can earn the R.T.(T) by completing a JRCERT-accredited radiation therapy program and documenting the ARRT clinical competency requirements. Check the ARRT Radiation Therapy Clinical Experience Requirements document for the current list of mandatory competencies.

ARRT Ethics Review

Every candidate completes the ARRT Ethics Review. This screens:

• Criminal history (misdemeanors and felonies — ARRT requires disclosure)
• Honor code violations (cheating, plagiarism) during schooling
• Previous ARRT disciplinary actions
• Drug or alcohol-related issues
• State license revocations or denials

If you answer "yes" to any ethics question, submit documentation early — an Ethics Review can add 3–6 months to your application timeline. Students with a complicated history can request a Pre-Application Review at any point in their program, even before graduation.

Graduation Verification

Your program director submits an Education Verification form to ARRT certifying you completed all didactic and clinical requirements. Apply no earlier than 90 days before graduation; the Candidate Status Report (CSR) will list anything missing.

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Exam Format: 200 Items in 3.5 Hours (2026)

The ARRT Radiation Therapy exam is a computer-based multiple-choice exam delivered in a single sitting at Pearson VUE.

Target pace: ~63 seconds per item if you reserve 10 minutes for flagged-item review. Most candidates finish in 2.5–3 hours.

How the 1–99 Scaled Score Works

ARRT does not publish a simple raw-score cutoff. Instead, the 170 scored items are statistically equated across forms and converted to a 1–99 scaled score. 75 is the passing standard, and has been the long-standing cut across all ARRT certification exams. A scaled 75 typically corresponds to roughly 65–70% of scored items correct, depending on form difficulty — do not target 75% raw as "safe."

Your score report lists category-level performance indicators (below, meets, or exceeds the category average) — useful for remediation if you fail, but you need the overall 75 to pass.

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The Five Content Categories (Current ARRT Radiation Therapy Content Specs)

Per the current ARRT Content Specifications for Radiation Therapy, the 170 scored items are distributed across five categories. Verify the exact weights for your test date at arrt.org, but the long-standing distribution is:

Procedures (30%) + Treatment Sciences (25%) = 55% of the exam. These two categories decide pass/fail.

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Category 1 Deep Dive — Patient Care (~15%)

You demonstrate you can manage a radiation therapy patient across the full simulation → treatment → follow-up continuum.

High-yield patient care facts:

• Spinal cord compression is the most common radiation oncology emergency — any new-onset back pain with neurologic deficit warrants immediate MRI and urgent RT within 24 hours.
• Febrile neutropenia (ANC <500 with fever >38.0°C) requires immediate broad-spectrum antibiotics; do not proceed with fraction until cleared.
• RTOG acute skin grading — Grade 1 (faint erythema), Grade 2 (bright erythema, dry desquamation), Grade 3 (moist desquamation in folds), Grade 4 (confluent moist desquamation, ulceration, hemorrhage, necrosis).

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Category 2 Deep Dive — Safety (~15%)

Covers patient, personnel, and public radiation protection plus general clinical safety.

High-yield safety calculations to memorize:

• Inverse square law: I1/I2 = (D2/D1)² — doubling distance reduces intensity 4×
• HVL/TVL: reducing intensity to 1/2 = 1 HVL; to 1/10 = 1 TVL ≈ 3.32 HVL
• Stuck HDR source: activate emergency retract → if fails, use remote T-handle or emergency containers → get patient out and door closed → call RSO → account for all staff

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Category 3 Deep Dive — Image Production and Treatment Verification (~15%)

You demonstrate you can simulate the patient, create a treatment plan reference, and verify daily setup.

High-yield IGRT facts:

• For prostate SBRT/IMRT, fiducial markers or intrafraction electromagnetic tracking are the standard — the prostate moves independently of bony anatomy.
• DIBH for left-breast RT reduces mean heart dose by ~30–50% vs free breathing.
• CBCT delivers ~1–5 cGy per acquisition — sum the imaging dose to the total dose when the ICRU report requires it.

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Category 4 Deep Dive — Radiation Oncology Procedures (~30%, the biggest category)

This is the clinical-technique core of the exam. Expect heavy testing on:

Worked Example — Lung SBRT Setup

Scenario: A 74-year-old with a 2.3 cm peripheral right-upper-lobe NSCLC is prescribed 54 Gy in 3 fractions over 8–14 days.

• Simulation: 4D-CT to capture tumor motion across the respiratory cycle; ITV (internal target volume) contoured on MIP or combined phases; vacuum-bag immobilization with arms up; abdominal compression if motion >1 cm
• Margins: GTV → ITV (motion) → PTV (typically 5 mm)
• Plan: VMAT with 2–4 partial arcs or robotic stereotactic delivery
• IGRT: CBCT before every fraction; 6-DOF couch correction
• Constraints (RTOG 0813 / TG-101): PTV D95 ≥ 95%; spinal cord max < 18 Gy; chest wall V30 < 30 cc (to reduce rib fracture risk)
• BED10 for 54 Gy/3 fx: 151.2 Gy — well above the ~100 Gy BED10 threshold associated with higher local control

Worked Example — Cervix HDR Brachytherapy

Scenario: Patient with Stage IIB cervical cancer, post 45 Gy pelvis EBRT + weekly cisplatin, now for HDR boost.

• Technique: Tandem and ovoids (T&O) or tandem and ring; intracavitary ± interstitial needles for extensive disease
• Imaging: MR-based planning is standard for GEC-ESTRO HR-CTV
• Typical prescription: 28 Gy in 4 fractions HDR to HR-CTV D90, twice weekly
• OAR constraints (EQD2 per GEC-ESTRO): Rectum D2cc ≤ 65–75 Gy; bladder D2cc ≤ 80–90 Gy; sigmoid D2cc ≤ 70–75 Gy (combined EBRT + HDR)
• Source: Ir-192 HDR afterloader, ~10 Ci at initial load; treatment time depends on current activity (decay 73.8-day half-life)

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Category 5 Deep Dive — Treatment Sciences (~25%)

Physics, dosimetry, and radiobiology. Heavy on calculations.

Dosimetry Calculation Cheat Sheet

MU at depth (SSD technique, simplified):

MU = prescribed dose at depth / (output × PDD × Sc × Sp × (SSDref + dref)² / (SSD + dref)²)

Cobalt-60 decay: A new 10,000 Ci Co-60 source after 5.27 years has decayed to 5,000 Ci (one half-life).

BED example — prostate SBRT 36.25 Gy / 5 fx (α/β = 1.5 Gy): BED1.5 = 5 × 7.25 × (1 + 7.25/1.5) = 36.25 × 5.83 ≈ 212 Gy1.5 — very high tumor BED because prostate's low α/β (~1.5 Gy) amplifies hypofractionation benefit. For comparison, BED3 (late-reacting normal tissue) = 36.25 × (1 + 7.25/3) ≈ 124 Gy3.

EQD2 for 54 Gy / 3 fx lung SBRT: BED10 = 151.2; EQD2 (α/β 10) = 151.2 ÷ 1.2 = 126 Gy.

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Pass Rate and Difficulty: The Honest Picture

ARRT publishes pass rates aggregated at the program level. National first-time pass rates for radiation therapy have historically run ~90–95% for candidates from JRCERT programs — higher than radiography because the candidate pool is smaller and highly selected.

Candidates who fail most commonly:

1. Underestimate dosimetry calculations. MU formulas, decay, BED/EQD2, and heterogeneity corrections recur on every form.
2. Weak brachytherapy knowledge. HDR/LDR workflows, source decay, emergency procedures — often under-taught in associate programs.
3. Gaps in TBI and TSEI. These "special procedure" items appear in low volume but are easy to miss if you never rotated through a transplant center.
4. Poor time management. 200 items in 210 minutes feels generous until the physics questions slow you down.
5. Missing patient-care scenarios. RTOG toxicity grading and oncologic emergencies (cord compression, SVC, tumor lysis) are repeatedly tested.

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12-Week ARRT Radiation Therapy Study Plan

Realistic plan for a soon-to-graduate JRCERT student testing in 2026. Scale to 16 weeks if working full-time.

Total: ~130 study hours over 12 weeks.

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Free and Paid Resources for ARRT Radiation Therapy Prep

The RT review market is smaller than radiography's but the core resources are well-established:

ASTRO free CE and ASRT student-member CE should carry you through the first recertification cycle without paying for expensive standalone CE.

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Cost & Registration: How to Apply for the ARRT Exam

Step-by-step (2026)

1. Complete your JRCERT program (didactic + clinical competencies documented)
2. Create an ARRT account at arrt.org
3. Submit your Radiation Therapy primary pathway application with the $200 fee (verify on arrt.org)
4. Complete the Ethics Review questions honestly — disclose any issues upfront
5. Program director submits Education Verification to ARRT
6. Receive Candidate Status Report (CSR) confirming eligibility; window opens for a 90-day scheduling period
7. Schedule at Pearson VUE — pick a convenient authorized center
8. Bring two forms of ID on test day (primary government photo + signature)
9. Unofficial pass/fail at the center; official score + category detail emailed within ~5 business days

If You Fail

• ARRT allows 3 attempts within a 3-year eligibility window from the date of your initial exam application.
• Each retake requires a new application and the full exam fee.
• After the 3-year window or 3 failed attempts, you must complete additional education and re-apply under current rules.

Focus your remediation on the categories where your score report lists "below average" — the category indicators are designed for this purpose.

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Recertification: Biennial CE + Continuing Qualifications Requirements (CQR)

Once you earn the R.T.(T), ARRT requires two separate maintenance programs to keep it active.

1. Biennial Continuing Education (CE)

Sources of free or low-cost CE:

• ASRT member benefit — hundreds of Category A+ CE courses free with membership
• ASTRO — free resident/member courses, annual meeting CE
• Employer in-services — often Category A approved
• RTAnswers.org (ASTRO/ASRT patient education library) — some CE modules
• Journal CE — Radiation Therapist, Radiologic Technology, IJROBP

2. Continuing Qualifications Requirements (CQR) — Every 10 Years

Every 10 years from your initial certification date, ARRT requires a Structured Self-Assessment (SSA) plus any associated CE modules to demonstrate continuing clinical competency. The CQR is specific to your certification category (radiation therapy has its own SSA mapped to the current content specs).

• SSA: online, category-aligned, untimed assessment that identifies knowledge gaps
• Gap CE: ARRT assigns Category A CE modules based on your SSA performance
• Timeframe: you have 3 years to complete the CQR once the 10-year mark is reached
• Failure to complete: certification lapses to inactive; you must complete requirements to reinstate

Plan ahead: start your CQR self-assessment ~8–9 years into your certification so you have time to complete any assigned remediation.

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Test-Taking Strategy for the ARRT Radiation Therapy Exam

Before the Exam

• Confirm your Pearson VUE appointment 48 hours ahead
• Bring two forms of ID (primary government photo + signature)
• Arrive 30 minutes early — Pearson VUE requires check-in time
• Eat a substantial breakfast; limit caffeine to your normal dose
• No reference materials allowed — leave study materials in the car

During the Exam

• Target 63 seconds per question (10 minutes held in reserve)
• Flag anything >90 seconds and return at end
• For image-based items, describe the anatomy/setup to yourself before selecting — don't pattern-match
• For calculation items, write out the formula, fill in variables, verify units; use the on-screen calculator
• For "most appropriate" / "first action" / "best choice" items — two options may be acceptable, but one is superior per ARRT scope, a QUANTEC constraint, or an ASTRO guideline
• Never leave a question blank — unanswered items are scored wrong

ARRT Question Style Tells

• "Which of the following is the MOST appropriate..." → apply a guideline, constraint, or scope rule
• "Initial" or "first" → identify the earliest step in a workflow
• "EXCEPT" or "NOT" — slow down and re-read; these flip the correct-answer logic
• Long clinical vignettes — skim for the actual question in the last sentence, then return to the vignette for specific values

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Common Pitfalls That Cost ARRT R.T.(T) Candidates Points

1. Weak MU and decay calculations. Drill until you can set up an MU equation and solve a decay problem in <60 seconds.
2. Confusing α/β ratios. Tumors and acute-reacting tissues ~10; late-reacting normal tissues ~3; prostate ~1.5 (special case).
3. Forgetting QUANTEC constraints. Spinal cord Dmax ≤ 45–50 Gy; lung V20 ≤ 30–35%; heart mean ≤ 26 Gy; parotid mean ≤ 26 Gy (keep at least one side).
4. Under-studying brachytherapy. HDR emergency procedures, source decay, and applicator-specific dose points are tested every form.
5. TBI setup details. Extended SSD, lung block transmission (~50%), dose-rate considerations — not intuitive if you never rotated through a transplant center.
6. Mixing up IMRT vs VMAT QA tools. ArcCheck/Delta4 for VMAT; MapCHECK / portal dosimetry common for static IMRT; gamma analysis criteria (typically 3%/2mm, 95% pass rate).
7. Missing dose limits. Occupational effective dose = 50 mSv/yr; declared pregnant worker = 5 mSv over gestation (not per year).
8. Skipping motion management. DIBH for left breast, 4D-CT for lung, abdominal compression for liver/pancreas SBRT — each has a signature indication.

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Salary and Career Outlook (2026)

BLS tracks radiation therapists under OCC 29-1124.

R.T.(T) Salary Ranges by Setting (2026)

Career ladder:

• Year 0: Pass R.T.(T) → work as staff therapist
• Year 1–3: Gain site-specific competence (SBRT, SRS, brachytherapy, pediatrics)
• Year 3–5: Specialize — lead therapist, SGRT/SRS specialist, or pursue medical dosimetry via a JRCERT-accredited CMD program
• Year 5+: Dosimetry, management, clinical education, vendor application (Varian, Elekta, Accuray)

The R.T.(T) → CMD (Certified Medical Dosimetrist) path is the single highest-return advancement — median dosimetrist salary runs $20,000–$40,000 higher than staff therapist, and the clinical background makes the transition natural.

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Related ARRT Credentials

Once you hold the R.T.(T), post-primary certifications can expand your scope:

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Ready to Pass the ARRT Radiation Therapy Exam in 2026?

Start Your FREE ARRT R.T.(T) Practice →Practice questions with detailed explanations

Patient Care + Safety drills, IGRT and simulation scenarios, full site-specific procedure sets (breast, lung, prostate, H&N, GYN, CNS, pediatrics), brachytherapy and TBI items, and physics + dosimetry calculation drills. 100% free, no credit card.

Pair OpenExamPrep drills with Mosby's Comprehensive Review and at least one full-length timed practice exam, and you'll walk into Pearson VUE ready — with a clear margin over the scaled 75 cut.

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Official Sources

• ARRT — Radiation Therapy certification page (arrt.org)
• ARRT Content Specifications for Radiation Therapy (current edition)
• ARRT Radiation Therapy Clinical Experience Requirements
• ARRT Standards of Ethics
• ARRT Continuing Education Requirements (biennial CE)
• ARRT Continuing Qualifications Requirements (CQR)
• JRCERT — Joint Review Committee on Education in Radiologic Technology (jrcert.org)
• ASRT — American Society of Radiologic Technologists (asrt.org)
• ASTRO — American Society for Radiation Oncology (astro.org)
• AAPM Task Group Reports (TG-51, TG-101, TG-142, TG-155)
• QUANTEC — IJROBP 2010 normal tissue dose constraints
• BLS OES 29-1124 — Radiation Therapists (salary and employment data)