OCN Radiation Therapy Nursing 1 — Questions and Answers
Question 1: What is the primary mechanism by which ionizing radiation destroys cancer cells?
- Inducing DNA strand breaks that lead to cell death (Correct answer)
- Disrupting the cell membrane integrity
- Inhibiting protein synthesis in tumor cells
- Blocking nutrient supply to the tumor
Correct answer: Inducing DNA strand breaks that lead to cell death
Ionizing radiation damages DNA by causing single- and double-strand breaks, which prevents cancer cells from replicating and leads to apoptosis.
Question 2: Which type of radiation therapy delivers treatment from a source located outside the patient's body?
- Brachytherapy
- External beam radiation therapy (EBRT) (Correct answer)
- Intraoperative radiation therapy
- Radiopharmaceutical therapy
Correct answer: External beam radiation therapy (EBRT)
External beam radiation therapy (EBRT) uses a machine located outside the body to direct radiation beams at the tumor site.
Question 3: A patient undergoing radiation therapy to the chest develops a dry, desquamating skin reaction at the treatment site. What is the most appropriate nursing intervention?
- Apply petroleum-based ointment and cover with a dry dressing
- Gently cleanse with mild soap and water and apply a recommended moisturizer (Correct answer)
- Rub the area vigorously to remove dead skin cells
- Apply an alcohol-based antiseptic to prevent infection
Correct answer: Gently cleanse with mild soap and water and apply a recommended moisturizer
Gentle cleansing with mild soap and water followed by a radiation-approved moisturizer minimizes irritation and supports skin integrity during radiation-induced dermatitis.
Question 4: What does fractionation in radiation therapy mean?
- Dividing the total radiation dose into smaller doses given over multiple sessions (Correct answer)
- Targeting only a fraction of the tumor volume per treatment
- Using multiple radiation beams from different angles simultaneously
- Delivering radiation in pulses rather than a continuous beam
Correct answer: Dividing the total radiation dose into smaller doses given over multiple sessions
Fractionation divides the total prescribed radiation dose into multiple smaller fractions delivered over days or weeks to allow normal tissue repair between treatments.
Question 5: Which radiation therapy technique uses multiple precisely aimed beams to deliver a high dose to a small tumor while minimizing exposure to surrounding healthy tissue?
- 3D conformal radiation therapy (3D-CRT)
- Intensity-modulated radiation therapy (IMRT)
- Stereotactic radiosurgery (SRS) (Correct answer)
- Total body irradiation (TBI)
Correct answer: Stereotactic radiosurgery (SRS)
Stereotactic radiosurgery (SRS) delivers highly precise, high-dose radiation to a small target in a single or few sessions, sparing adjacent normal tissue.
Question 6: What is brachytherapy?
- Radiation delivered by a machine positioned at a long distance from the patient
- Placement of radioactive sources directly inside or adjacent to the tumor (Correct answer)
- A low-dose rate form of external beam radiation
- Targeted radiopharmaceutical therapy given intravenously
Correct answer: Placement of radioactive sources directly inside or adjacent to the tumor
Brachytherapy involves placing radioactive implants (seeds, wires, or catheters) directly within or next to the tumor to deliver a concentrated local dose.
Question 7: What is the primary purpose of a radiation therapy simulation appointment?
- To administer the first fraction of radiation
- To identify and map the treatment field, verify patient positioning, and create immobilization devices (Correct answer)
- To perform a biopsy for treatment planning
- To educate the patient about chemotherapy side effects
Correct answer: To identify and map the treatment field, verify patient positioning, and create immobilization devices
Simulation is a planning session in which the radiation oncology team uses imaging to delineate the tumor, design the treatment field, and fabricate immobilization devices for reproducibility.
OCN Radiation Therapy Nursing 1
What is the primary mechanism by which ionizing radiation destroys cancer cells?