California Radiation Therapy Technologist
Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary function of a linear accelerator in radiation
therapy?
A. To monitor patient vital signs
B. To generate and deliver high-energy x-rays or electrons to treat
tumors
C. To calibrate imaging equipment
D. To diagnose cancer
The linear accelerator (LINAC) is designed to generate and deliver
therapeutic radiation with precision for cancer treatment.
2. Which type of radiation has the highest linear energy transfer (LET)?
A. X-rays
B. Gamma rays
C. Alpha particles
D. Beta particles
Alpha particles deposit more energy over a short distance compared to
other types, making their LET highest.
3. The Bragg peak is a key principle in which type of radiation therapy?
A. Gamma Knife
, B. Proton therapy
C. CyberKnife
D. Electron therapy
Proton therapy delivers peak energy at a specific depth (Bragg peak),
minimizing dose to surrounding tissue.
4. What is the recommended dose limit for occupational radiation
exposure per year in the U.S.?
A. 10 mSv
B. 25 mSv
C. 50 mSv
D. 100 mSv
The NCRP recommends a maximum of 50 mSv annually for radiation
workers.
5. Which organization is responsible for setting radiation protection
guidelines in the U.S.?
A. CDC
B. NCRP
C. FDA
D. OSHA
The National Council on Radiation Protection and Measurements
(NCRP) provides guidelines on exposure limits.
6. What imaging modality is most commonly used for treatment planning
in radiation therapy?
A. MRI
B. Ultrasound
C. CT scan
D. PET scan
CT scans offer clear anatomical details and electron density info crucial
for radiation dose calculations.
, 7. Which is the most radiosensitive phase of the cell cycle?
A. G1
B. M phase
C. S phase
D. G2
Cells are most sensitive to radiation during mitosis (M phase).
8. What is the main purpose of a bolus in radiation therapy?
A. To bring the dose closer to the skin surface
B. To reduce patient discomfort
C. To shield vital organs
D. To decrease beam energy
Boluses are used to shift the dose buildup region closer to the surface
for superficial tumors.
9. Which of the following is a late radiation effect?
A. Skin erythema
B. Fibrosis
C. Nausea
D. Fatigue
Fibrosis is a late, potentially permanent effect of radiation damage to
tissue.
10. What is the function of multileaf collimators (MLCs) in a LINAC?
A. To cool the beam
B. To shape the radiation beam to match tumor geometry
C. To increase beam energy
D. To detect beam misalignment
MLCs are used to conform the radiation beam to the shape of the
tumor, sparing healthy tissue.
11. What does fractionation in radiation therapy refer to?
A. Dividing tumors into segments
Practice Exam Questions And Correct
Answers (Verified Answers) Plus Rationales
2026 Q&A | Instant Download Pdf
1. What is the primary function of a linear accelerator in radiation
therapy?
A. To monitor patient vital signs
B. To generate and deliver high-energy x-rays or electrons to treat
tumors
C. To calibrate imaging equipment
D. To diagnose cancer
The linear accelerator (LINAC) is designed to generate and deliver
therapeutic radiation with precision for cancer treatment.
2. Which type of radiation has the highest linear energy transfer (LET)?
A. X-rays
B. Gamma rays
C. Alpha particles
D. Beta particles
Alpha particles deposit more energy over a short distance compared to
other types, making their LET highest.
3. The Bragg peak is a key principle in which type of radiation therapy?
A. Gamma Knife
, B. Proton therapy
C. CyberKnife
D. Electron therapy
Proton therapy delivers peak energy at a specific depth (Bragg peak),
minimizing dose to surrounding tissue.
4. What is the recommended dose limit for occupational radiation
exposure per year in the U.S.?
A. 10 mSv
B. 25 mSv
C. 50 mSv
D. 100 mSv
The NCRP recommends a maximum of 50 mSv annually for radiation
workers.
5. Which organization is responsible for setting radiation protection
guidelines in the U.S.?
A. CDC
B. NCRP
C. FDA
D. OSHA
The National Council on Radiation Protection and Measurements
(NCRP) provides guidelines on exposure limits.
6. What imaging modality is most commonly used for treatment planning
in radiation therapy?
A. MRI
B. Ultrasound
C. CT scan
D. PET scan
CT scans offer clear anatomical details and electron density info crucial
for radiation dose calculations.
, 7. Which is the most radiosensitive phase of the cell cycle?
A. G1
B. M phase
C. S phase
D. G2
Cells are most sensitive to radiation during mitosis (M phase).
8. What is the main purpose of a bolus in radiation therapy?
A. To bring the dose closer to the skin surface
B. To reduce patient discomfort
C. To shield vital organs
D. To decrease beam energy
Boluses are used to shift the dose buildup region closer to the surface
for superficial tumors.
9. Which of the following is a late radiation effect?
A. Skin erythema
B. Fibrosis
C. Nausea
D. Fatigue
Fibrosis is a late, potentially permanent effect of radiation damage to
tissue.
10. What is the function of multileaf collimators (MLCs) in a LINAC?
A. To cool the beam
B. To shape the radiation beam to match tumor geometry
C. To increase beam energy
D. To detect beam misalignment
MLCs are used to conform the radiation beam to the shape of the
tumor, sparing healthy tissue.
11. What does fractionation in radiation therapy refer to?
A. Dividing tumors into segments
