ARRT Radiation Therapy (T) Exam 2026: Certification Practice Test
— Treatment Planning, Radiation Physics, Patient Care, Dosimetry &
Clinical Procedures — 190 Multiple-Choice Questions with Answers
& Detailed Rationales
SECTION 1: PATIENT CARE AND MANAGEMENT (Questions 1–48)
Question 1
A patient receiving radiation to the head and neck reports a new onset of difficulty
swallowing and a white coating on the tongue and buccal mucosa. The therapist notes the
patient completed antibiotic therapy two weeks ago. Which condition is most likely?
A. Radiation-induced xerostomia
B. Oral candidiasis
C. Radiation caries
D. Trismus
Correct Answer: B
Explanation: Antibiotic use disrupts normal flora, predisposing to Candida; white coating
confirms fungal infection. Clinical Pearl: Assess for concurrent steroid use, which further
immunosuppresses.
Question 2
A patient with metastatic disease to the lumbar spine calls reporting new-onset numbness in
the saddle region and difficulty urinating. The therapist should immediately:
A. Schedule the patient for a routine follow-up appointment.
B. Instruct the patient to take prescribed corticosteroids and monitor symptoms.
C. Notify the radiation oncologist urgently for possible cord compression.
,D. Advise the patient to increase oral fluid intake and rest.
Correct Answer: C
Explanation: Saddle anesthesia and urinary retention suggest cauda equina syndrome, a
radiation oncology emergency requiring immediate intervention. Best Practice: Never delay
reporting of neurologic deficits.
Question 3
During CT simulation for prostate cancer, the therapist notices the patient's bladder is
empty, whereas the prescription specifies a full bladder for treatment. The most appropriate
action is to:
A. Proceed with simulation since bladder volume does not affect prostate position.
B. Reschedule simulation after instructing the patient to empty the bladder.
C. Ask the patient to drink water and wait for the bladder to fill before proceeding.
D. Document the bladder status and continue without intervention.
Correct Answer: C
Explanation: Bladder filling status affects prostate position and reproducibility; simulation
conditions must match treatment conditions. Clinical Pearl: Provide written bladder-filling
instructions at scheduling.
Question 4
A patient undergoing pelvic radiation for cervical cancer reports a temperature of 38.5°C
(101.3°F) and chills during treatment. Which action is the priority?
A. Administer acetaminophen and continue treatment.
B. Hold treatment and notify the radiation oncologist immediately.
,C. Continue treatment and instruct the patient to monitor temperature at home.
D. Place a warm blanket on the patient to manage chills.
Correct Answer: B
Explanation: Fever during pelvic radiation may indicate infection or sepsis; treatment should
be held pending physician evaluation. Best Practice: All febrile episodes during radiation
require prompt medical assessment.
Question 5
A patient with a history of anxiety and claustrophobia is scheduled for MRI simulation.
Which intervention is most appropriate?
A. Cancel the MRI and proceed with CT simulation only.
B. Administer oral contrast to reduce anxiety.
C. Arrange for a mild anxiolytic with physician approval and extended appointment time.
D. Perform the MRI without modification and instruct the patient to close their eyes.
Correct Answer: C
Explanation: Anxiolytics with physician approval and extra time improve tolerance; MRI may
be essential for target delineation. Clinical Pearl: Assess anxiety history at scheduling to
allow premedication.
Question 6
A breast cancer patient receiving whole-breast radiation with a tumor bed boost asks why
the boost is necessary. The best explanation is:
A. The boost increases total treatment duration for better outcomes.
B. The boost delivers additional dose to the highest-risk region for recurrence.
, C. The boost reduces radiation exposure to the heart.
D. The boost eliminates the need for systemic therapy.
Correct Answer: B
Explanation: Tumor bed boost targets the area of highest local recurrence risk, improving
local control. Best Practice: Explain the rationale in patient-specific terms to improve
adherence.
Question 7
A patient receiving radiation for lung cancer develops a nonproductive cough and low-grade
fever 10 weeks after completing treatment. Imaging reveals a localized infiltrate within the
radiation field. The likely diagnosis is:
A. Bacterial pneumonia
B. Radiation pneumonitis
C. Pulmonary embolism
D. Tumor progression
Correct Answer: B
Explanation: Radiation pneumonitis typically occurs 6 weeks to 6 months post-treatment,
confined to the radiation field. Clinical Pearl: Differentiate from infection by localization and
timing.
Question 8
A patient with head and neck cancer undergoing concurrent chemoradiation has a white
blood cell count of 1.8 × 10³/µL. The most important instruction to the patient is:
A. Increase consumption of fresh fruits and vegetables.
— Treatment Planning, Radiation Physics, Patient Care, Dosimetry &
Clinical Procedures — 190 Multiple-Choice Questions with Answers
& Detailed Rationales
SECTION 1: PATIENT CARE AND MANAGEMENT (Questions 1–48)
Question 1
A patient receiving radiation to the head and neck reports a new onset of difficulty
swallowing and a white coating on the tongue and buccal mucosa. The therapist notes the
patient completed antibiotic therapy two weeks ago. Which condition is most likely?
A. Radiation-induced xerostomia
B. Oral candidiasis
C. Radiation caries
D. Trismus
Correct Answer: B
Explanation: Antibiotic use disrupts normal flora, predisposing to Candida; white coating
confirms fungal infection. Clinical Pearl: Assess for concurrent steroid use, which further
immunosuppresses.
Question 2
A patient with metastatic disease to the lumbar spine calls reporting new-onset numbness in
the saddle region and difficulty urinating. The therapist should immediately:
A. Schedule the patient for a routine follow-up appointment.
B. Instruct the patient to take prescribed corticosteroids and monitor symptoms.
C. Notify the radiation oncologist urgently for possible cord compression.
,D. Advise the patient to increase oral fluid intake and rest.
Correct Answer: C
Explanation: Saddle anesthesia and urinary retention suggest cauda equina syndrome, a
radiation oncology emergency requiring immediate intervention. Best Practice: Never delay
reporting of neurologic deficits.
Question 3
During CT simulation for prostate cancer, the therapist notices the patient's bladder is
empty, whereas the prescription specifies a full bladder for treatment. The most appropriate
action is to:
A. Proceed with simulation since bladder volume does not affect prostate position.
B. Reschedule simulation after instructing the patient to empty the bladder.
C. Ask the patient to drink water and wait for the bladder to fill before proceeding.
D. Document the bladder status and continue without intervention.
Correct Answer: C
Explanation: Bladder filling status affects prostate position and reproducibility; simulation
conditions must match treatment conditions. Clinical Pearl: Provide written bladder-filling
instructions at scheduling.
Question 4
A patient undergoing pelvic radiation for cervical cancer reports a temperature of 38.5°C
(101.3°F) and chills during treatment. Which action is the priority?
A. Administer acetaminophen and continue treatment.
B. Hold treatment and notify the radiation oncologist immediately.
,C. Continue treatment and instruct the patient to monitor temperature at home.
D. Place a warm blanket on the patient to manage chills.
Correct Answer: B
Explanation: Fever during pelvic radiation may indicate infection or sepsis; treatment should
be held pending physician evaluation. Best Practice: All febrile episodes during radiation
require prompt medical assessment.
Question 5
A patient with a history of anxiety and claustrophobia is scheduled for MRI simulation.
Which intervention is most appropriate?
A. Cancel the MRI and proceed with CT simulation only.
B. Administer oral contrast to reduce anxiety.
C. Arrange for a mild anxiolytic with physician approval and extended appointment time.
D. Perform the MRI without modification and instruct the patient to close their eyes.
Correct Answer: C
Explanation: Anxiolytics with physician approval and extra time improve tolerance; MRI may
be essential for target delineation. Clinical Pearl: Assess anxiety history at scheduling to
allow premedication.
Question 6
A breast cancer patient receiving whole-breast radiation with a tumor bed boost asks why
the boost is necessary. The best explanation is:
A. The boost increases total treatment duration for better outcomes.
B. The boost delivers additional dose to the highest-risk region for recurrence.
, C. The boost reduces radiation exposure to the heart.
D. The boost eliminates the need for systemic therapy.
Correct Answer: B
Explanation: Tumor bed boost targets the area of highest local recurrence risk, improving
local control. Best Practice: Explain the rationale in patient-specific terms to improve
adherence.
Question 7
A patient receiving radiation for lung cancer develops a nonproductive cough and low-grade
fever 10 weeks after completing treatment. Imaging reveals a localized infiltrate within the
radiation field. The likely diagnosis is:
A. Bacterial pneumonia
B. Radiation pneumonitis
C. Pulmonary embolism
D. Tumor progression
Correct Answer: B
Explanation: Radiation pneumonitis typically occurs 6 weeks to 6 months post-treatment,
confined to the radiation field. Clinical Pearl: Differentiate from infection by localization and
timing.
Question 8
A patient with head and neck cancer undergoing concurrent chemoradiation has a white
blood cell count of 1.8 × 10³/µL. The most important instruction to the patient is:
A. Increase consumption of fresh fruits and vegetables.
