RTT Study Guide 2026: How to Pass on Your First Attempt

What You Are Actually Studying For

This guide covers the Registered Technologist - Radiation Therapy credential, issued by the American Registry of Radiologic Technologists (ARRT) under its Radiation Therapy (T) discipline. "RTT" is simply the abbreviation used on this site; it is not ARRT's formal discipline designation, and it should not be confused with any other credential that happens to share those letters. If you want a plain-language orientation first, see What Is RTT Certification? or What Does RTT Stand For?.

The credential is earned through ARRT's primary pathway. That matters for how you prepare: you are not adding a postprimary examination on top of Radiography. Candidates arrive from an ARRT-verified radiation therapy educational program, with the didactic coursework and clinical competencies already behind them. The exam then tests whether you can apply that training under time pressure, across the full scope of treatment planning, delivery, physics, safety and patient management.

The employers who value this credential are the ones that deliver external beam radiation: hospital radiation oncology departments, cancer centers and freestanding treatment facilities. If you are weighing the credential's career value, the RTT jobs overview and the ROI analysis cover that side in more depth. This article is about passing.

How the 230-Question Exam Works

The exam is computer-based and delivered at Pearson VUE test centers. You will see 230 questions in total: 200 are scored and 30 are unscored pilot questions that ARRT is trialing for future exams. You cannot tell which is which, so treat every item as if it counts.

Two practical consequences follow. First, 230 minutes for 230 questions gives you roughly one minute per item, which is comfortable for recall questions but tight for dose calculation items, so practice working them quickly on an on-screen calculator rather than a handheld one you will not be allowed to bring. Second, because you must answer before moving on, you cannot skip a hard question and return to it blank. Make your best selection, flag it, and come back if time allows.

Reading the Blueprint: Where the 200 Scored Questions Go

ARRT publishes official counts of scored questions per category in the Radiation Therapy Content Specifications. For examinations through January 31, 2027, the controlling document is the version board-approved in January 2021 and effective January 1, 2022. Here are the counts, which I am deliberately presenting as counts rather than converting into percentages:

Procedures alone accounts for more scored questions than Patient Care and Safety combined. A study plan that spreads time evenly across the three domains will under-invest in the part of the exam that most determines your result. For a deeper walk through each category, the complete guide to all three RTT content areas goes subcategory by subcategory.

Procedures: The Domain That Decides Your Result

Treatments (35 questions)

Because this is the biggest slice, study it as workflow, not as a list of terms. Be able to narrate what happens from a patient's arrival at the treatment unit through verification, delivery and documentation, and to identify the correct response when an image or setup does not match what was planned. These are the questions where clinical time pays off, so draw on your own competency experiences: the 16 radiation treatment procedures you performed for sign-off are direct preparation.

Prescription and Dose Calculation (24 questions)

Dose calculation is where preparation and anxiety collide. The fix is repetition under realistic conditions. Work problems with an on-screen calculator interface so that the exam's tool is not a surprise, show every step, and note which unit system you are in. SI units are primary on this exam, so build fluency there instead of leaning on older units.

Treatment Sites and Tumors (26 questions)

Build a one-page summary per major treatment site: relevant anatomy, typical treatment considerations, critical nearby structures and expected acute effects. Staging appears only at a basic-concepts level, so do not sink hours into memorizing site-specific staging systems.

Treatment Volume Localization (18 questions)

This is the smallest Procedures subcategory but it connects directly to simulation. Review how imaging supports volume definition, patient immobilization and positioning rationale, and how reference marks and setup information flow from simulation to the treatment unit.

Safety: Physics, Radiobiology and Quality Assurance

Your clinical requirements include five quality-control activities, and they are worth revisiting as study material. Ask yourself for each one: what is being checked, why, what tolerance matters, and what you would do if a result fell outside it. That framing converts a clinical memory into an exam-ready answer.

For physics and radiobiology, aim for explanation-level understanding, not formula recitation alone. Know what a concept means for treatment: why one beam characteristic suits a given depth, why fractionation protects normal tissue, why some tissues tolerate more dose than others. Brachytherapy is covered only at a basic level here: common-use concepts, dose to surrounding tissue, and radiation protection, rather than detailed procedures or isotope characteristics. That is a reason to limit, not skip, your brachytherapy review.

Patient Care: Smaller Domain, Real Points

Radiation therapy patients are seen daily for extended courses, so the exam expects you to recognize treatment-related side effects, know when a concern needs escalation and understand how records support safe care. Scenario questions reward the answer that is both safe and professionally appropriate, so read for what you should do first. The clinical requirement to complete CPR and six other patient-care activities is a good prompt for review here.

What the 2026 Scope Leaves Out

Knowing the edges of the exam saves study hours. Per the content specifications that govern examinations through January 31, 2027:

• SI units are primary.
• Brachytherapy is limited to basic common-use, surrounding-tissue-dose and radiation-protection concepts.
• Staging is limited to basic concepts rather than site-specific staging.
• Specific CPT codes are excluded.

A Domain-Ordered Study Schedule

This is the one place for a week-by-week structure, and it is built around the blueprint, not generic habits. The logic: front-load Procedures because it is the biggest, interleave dose calculation early because it takes the longest to become automatic, and finish with full-length timed practice. Adjust the length to your own calendar.

For a compact end-of-study review, the RTT cheat sheet condenses the must-know facts, and the broader RTT training overview helps if you are still deciding how to build your preparation. For full-length simulations, use the RTT Exam Prep practice tests.

Scoring, Attempts and the Cut-Score Change

The passing score is 75 on ARRT's scaled range of 1 to 99. This is a scaled score, so 75 does not mean 75% of questions correct, and you should not try to back-calculate a raw-percentage target from it. The detailed explanation lives in the RTT passing score guide.

A revised examination cut-score standard took effect February 1, 2025, while the reported passing score remains 75 scaled. In practice that means older advice about "how many questions you can miss" is unreliable; focus on mastery across the blueprint.

ARRT's Annual Exam Report for 2025 lists a first-time candidate pass rate of 77.1% (n=958). That is useful context: most first-time candidates pass, which tells you the exam is demanding but well within reach for a prepared graduate. For how to interpret that figure, see the RTT pass rate analysis and how hard the RTT exam is.

You have three examination attempts within three years of the opening of your initial examination window. Reapplication costs $200 each time, so the financial case for preparing thoroughly the first time is straightforward on top of the scheduling cost.

Eligibility, Fees and Clinical Sign-Offs

Before you can sit the exam, several things must be true. The primary eligibility requirements include:

• An associate degree or higher from an ARRT-recognized accredited institution; the degree may be in any major and must be conferred before the examination.
• Completion of an ARRT-verified radiation therapy educational program and its didactic and clinical competencies.
• Compliance with ARRT ethics requirements.

The degree must be earned and the application submitted no more than three years after program completion. That initial application deadline is separate from the three-year window for examination attempts, so do not conflate the two clocks. An existing Radiography credential is not a prerequisite. For the full picture, read the RTT requirements guide.

The initial application fee is $225. Combined with a possible $200 reapplication, the numbers are laid out in the RTT certification cost breakdown.

Clinical Competency Requirements as Study Material

Your program director or designee verifies clinical competency through in-person direct observation; remote or virtual observation is not accepted. The requirements themselves double as a checklist of exam-relevant tasks:

• CPR plus six other patient-care activities
• Five quality-control activities
• Six treatment-simulation procedures
• Dose calculations for six treatment plans
• Fabrication of three accessory devices
• Participation in four special treatment procedures
• One specialized simulation procedure and one specialized accessory-device construction process
• 16 radiation treatment procedures, including at least 13 on patients and no more than three simulated

If any category feels thin in your memory, that is a signal to study the underlying concepts harder, since you may have less lived reinforcement there.

After You Pass: Renewal and CQR

Certification is not a one-time event. You maintain registration through annual renewal ($65, regardless of how many ARRT credentials you hold), continued compliance with ethics requirements, and 24 approved continuing education credits per two-year biennium (per biennium, not per credential). Credentials earned on or after January 1, 2011 also require Continuing Qualifications Requirements every 10 years: a professional profile, a structured self-assessment and any prescribed CE. ARRT also lets you accept the maximum CQR CE prescription instead of taking the self-assessment.

Knowing this up front is part of an informed decision about the credential; the earnings side is covered in the RTT salary guide.

Frequently Asked Questions