What Does RTT Mean?

The Short Answer: What RTT Means Here

When you see "RTT" on this site, it stands for Registered Technologist - Radiation Therapy. It is the credential earned by radiation therapists who pass the American Registry of Radiologic Technologists (ARRT) examination in the Radiation Therapy discipline. These are the professionals who deliver prescribed radiation treatments to cancer patients, operate linear accelerators and related equipment, take part in treatment simulation, and keep patients safe and well-informed through a demanding course of care.

Why This Acronym Causes Confusion

Three letters are not much to go on, and "RTT" is used across healthcare, technology, and other fields to mean entirely different things. That is why candidates searching the term sometimes land on material about unrelated credentials or concepts, with different certifying bodies, different fees, and different rules.

The practical takeaway is simple: when you evaluate any exam resource, check that it identifies the certifying body (ARRT), the discipline (Radiation Therapy), and the delivery partner (Pearson VUE). If a page cites facts that do not match those anchors, it is describing something else. Everything in this article refers only to the ARRT Radiation Therapy pathway. For related framing, see What Is RTT? and RTT Meaning.

What the Credential Covers

The exam measures whether an entry-level radiation therapist can practice safely and competently. Its official major content categories are three domains, each with a defined count of scored questions out of 200.

These are question counts, not official percentages, and they apply to the content specifications in force through January 31, 2027. A separate 2027 specification takes effect February 1, 2027, so check which version governs your test date. Our complete guide to all 3 RTT content areas breaks each domain down further.

Scope boundaries worth knowing

• SI units are the primary system of measurement.
• Brachytherapy coverage is limited to basic common-use, surrounding-tissue-dose, and radiation-protection concepts, not detailed procedures or isotope characteristics.
• Staging is tested only at the level of basic concepts, not site-specific staging systems.
• Specific CPT codes are excluded.

Knowing what is out of scope saves real study time. A candidate who memorizes isotope half-lives or site-by-site staging tables is spending effort the specification says will not be tested.

How the Exam Is Built

Because 30 questions are unscored pilot items, you cannot tell which ones count. Treat every question as if it does. The mix of formats also matters: an ordered-response item, for example, asks you to sequence steps correctly, which rewards understanding of workflow over isolated fact recall. For a view of overall difficulty, see How Hard Is the RTT Exam?

Who Qualifies to Sit for It

Most candidates qualify through the ARRT primary eligibility pathway. The pillars are education, clinical competency, and ethics.

1. Degree: an associate degree or higher from an ARRT-recognized accredited institution. The degree can be in any major but must be conferred before you take the exam.
2. Program: completion of an ARRT-verified radiation therapy educational program, including its didactic coursework and clinical competencies.
3. Ethics: compliance with ARRT ethics requirements.

Two timing details trip people up. First, the degree must be earned and the application submitted no more than three years after program completion. Second, that application deadline is separate from the later three-year window for exam attempts. An existing Radiography credential is not a universal prerequisite, so you do not need to be a radiographer first.

The clinical competency load

The clinical requirements are substantial and specific to radiation therapy:

• 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
• Sixteen radiation treatment procedures, with at least 13 performed on patients and no more than three simulated

Exam-Day Mechanics and Fees

The initial application fee is $225, and an examination reapplication costs $200. For the full cost picture, including renewal, see our RTT certification cost breakdown.

What to expect at the testing center

• The exam is closed book.
• Basic and scientific on-screen calculators are available. Pearson can supply a basic four-function calculator on request. Personal calculators are prohibited.
• You must answer each item before advancing, but you can flag questions and return to them.
• Your 250-minute appointment includes a tutorial, a nondisclosure agreement, and a survey in addition to the 230 minutes of answering time.

The on-screen scientific calculator matters because Prescription and Dose Calculation is a tested area. Practice with a similar tool beforehand so the interface is not a distraction. Scheduling specifics are covered in RTT exam dates and deadlines.

What the Score Actually Means

ARRT reports results on a scaled range of 1 to 99, and the passing score is 75. That is a scaled score, not 75% correct. The number of raw questions you must answer correctly to reach a scaled 75 is determined by the exam's standard, so do not try to convert it into a percentage target.

A revised examination cut-score standard took effect February 1, 2025, though the reported passing score remains 75 scaled. You get three examination attempts within three years of the opening of your initial examination window.

For context, ARRT's 2025 annual report shows 77.1% of first-time candidates passing in 2025 (n=958). Read that as a single-year data point rather than a promise. More analysis is in RTT pass rate: what the data shows and RTT passing score explained.

Staying Credentialed After You Pass

Earning the credential is the start of an ongoing obligation. To maintain certification and registration you need:

• Annual renewal: $65, regardless of how many ARRT credentials you hold.
• Ethics compliance: continuing, not one-time.
• Continuing education: 24 approved CE credits per two-year biennium, counted per biennium rather than per credential.
• Continuing Qualifications Requirements (CQR): for credentials earned on or after January 1, 2011, every 10 years. This involves a professional profile, a structured self-assessment, and any prescribed CE. ARRT also permits accepting the maximum CQR CE prescription instead of taking the self-assessment.

Where Radiation Therapists Work

Radiation therapists are employed where cancer treatment is delivered. Typical settings include hospital radiation oncology departments, cancer centers, and freestanding outpatient radiation therapy clinics. Some also move into dosimetry, treatment planning support, education, or department leadership as their careers develop.

Daily work blends technical precision with sustained patient contact. Treatment courses often run over multiple visits, so therapists build relationships with patients and monitor how they are tolerating care. That is why Patient Care is a full exam domain, not an afterthought. To explore openings, see RTT jobs, and for earnings context, read the RTT salary guide. If you are weighing the investment, is the RTT certification worth it? walks through the tradeoffs.

Sequencing Your Prep by Domain

Because the domains are weighted so unevenly, your calendar should be too. Procedures carries 103 of 200 scored questions, so it deserves the most hours, but Safety's physics and radiobiology content is often the foundation that makes dose calculation and localization make sense.

Adjust the timeline to your own strengths. For a complete plan, start with the RTT study guide, keep the RTT cheat sheet handy for last-minute review, and test yourself with realistic questions on the main practice test site.

Frequently Asked Questions