ONS Radiation Therapy Certificate –Exam
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The primary goal of external beam radiation therapy is to:
A. Eliminate all normal cells in the treatment field
B. Deliver a uniform dose to the entire body
C. Maximize tumor control while minimizing damage to normal
tissue
D. Replace surgical intervention
Radiation therapy is designed to target malignant cells while
sparing surrounding healthy tissue as much as possible.
2. Which unit is used to measure absorbed radiation dose?
A. Curie
B. Sievert
C. Gray
D. Becquerel
The gray (Gy) measures absorbed dose and is the standard unit
used in radiation therapy.
3. Fractionation in radiation therapy refers to:
A. Dividing the tumor into sections
B. Delivering the total dose in multiple smaller doses over time
C. Combining chemotherapy with radiation
, D. Using different radiation machines
Fractionation allows normal tissues time to repair while enhancing
tumor cell kill.
4. Which cells are most radiosensitive?
A. Muscle cells
B. Nerve cells
C. Rapidly dividing cells
D. Mature red blood cells
Cells with high mitotic activity are more susceptible to radiation
damage.
5. The simulation process in radiation therapy is used to:
A. Deliver the first dose of treatment
B. Assess tumor response
C. Plan and map the treatment area
D. Educate the patient on side effects
Simulation ensures accurate targeting and reproducibility of
treatment positioning.
6. What is the primary purpose of immobilization devices?
A. Reduce treatment time
B. Maintain consistent patient positioning
C. Increase radiation dose
D. Prevent skin reactions
Immobilization improves accuracy and reduces exposure to
surrounding tissues.
7. Acute radiation side effects typically occur:
A. Years after treatment
B. Only after chemotherapy
, C. During or shortly after treatment
D. Only in high-dose therapy
Acute effects are related to rapidly dividing normal tissues.
8. Late radiation effects are characterized by:
A. Rapid onset and reversibility
B. Delayed onset and often permanent damage
C. Occurring only in pediatric patients
D. Affecting only skin tissue
Late effects may develop months to years after therapy.
9. Which factor most influences tissue tolerance to radiation?
A. Patient age
B. Total dose and fraction size
C. Treatment machine brand
D. Time of day treatment is given
Dose and fractionation determine the risk of tissue injury.
10. The ALARA principle stands for:
A. All Levels Are Radiation Acceptable
B. Allow Limited Radiation Always
C. As Low As Reasonably Achievable
D. Authorized Levels of Radiation Application
ALARA guides radiation safety to minimize exposure.
11. Which radiation modality uses radioactive sources placed
inside or near the tumor?
A. External beam therapy
B. Brachytherapy
C. Proton therapy
D. Stereotactic radiosurgery
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. The primary goal of external beam radiation therapy is to:
A. Eliminate all normal cells in the treatment field
B. Deliver a uniform dose to the entire body
C. Maximize tumor control while minimizing damage to normal
tissue
D. Replace surgical intervention
Radiation therapy is designed to target malignant cells while
sparing surrounding healthy tissue as much as possible.
2. Which unit is used to measure absorbed radiation dose?
A. Curie
B. Sievert
C. Gray
D. Becquerel
The gray (Gy) measures absorbed dose and is the standard unit
used in radiation therapy.
3. Fractionation in radiation therapy refers to:
A. Dividing the tumor into sections
B. Delivering the total dose in multiple smaller doses over time
C. Combining chemotherapy with radiation
, D. Using different radiation machines
Fractionation allows normal tissues time to repair while enhancing
tumor cell kill.
4. Which cells are most radiosensitive?
A. Muscle cells
B. Nerve cells
C. Rapidly dividing cells
D. Mature red blood cells
Cells with high mitotic activity are more susceptible to radiation
damage.
5. The simulation process in radiation therapy is used to:
A. Deliver the first dose of treatment
B. Assess tumor response
C. Plan and map the treatment area
D. Educate the patient on side effects
Simulation ensures accurate targeting and reproducibility of
treatment positioning.
6. What is the primary purpose of immobilization devices?
A. Reduce treatment time
B. Maintain consistent patient positioning
C. Increase radiation dose
D. Prevent skin reactions
Immobilization improves accuracy and reduces exposure to
surrounding tissues.
7. Acute radiation side effects typically occur:
A. Years after treatment
B. Only after chemotherapy
, C. During or shortly after treatment
D. Only in high-dose therapy
Acute effects are related to rapidly dividing normal tissues.
8. Late radiation effects are characterized by:
A. Rapid onset and reversibility
B. Delayed onset and often permanent damage
C. Occurring only in pediatric patients
D. Affecting only skin tissue
Late effects may develop months to years after therapy.
9. Which factor most influences tissue tolerance to radiation?
A. Patient age
B. Total dose and fraction size
C. Treatment machine brand
D. Time of day treatment is given
Dose and fractionation determine the risk of tissue injury.
10. The ALARA principle stands for:
A. All Levels Are Radiation Acceptable
B. Allow Limited Radiation Always
C. As Low As Reasonably Achievable
D. Authorized Levels of Radiation Application
ALARA guides radiation safety to minimize exposure.
11. Which radiation modality uses radioactive sources placed
inside or near the tumor?
A. External beam therapy
B. Brachytherapy
C. Proton therapy
D. Stereotactic radiosurgery
