AOCNP Radiation Therapy Principles and Side Effects 2 — Questions and Answers
Question 1: A patient receiving radiation to the head and neck develops severe mucositis. Which intervention is most important for maintaining nutritional status?
- Encourage small frequent sips of water only
- Insert a percutaneous endoscopic gastrostomy (PEG) tube or nasogastric tube as needed (Correct answer)
- Administer IV dexamethasone for 3 days
- Recommend soft mechanical diet only
Correct answer: Insert a percutaneous endoscopic gastrostomy (PEG) tube or nasogastric tube as needed
Severe radiation-induced mucositis commonly results in dysphagia, odynophagia, and inability to maintain adequate oral intake. Prophylactic or early PEG placement is often recommended for patients receiving concurrent chemoradiation to the head and neck to maintain nutrition and hydration.
Question 2: Prophylactic cranial irradiation (PCI) is standard of care for which cancer type to reduce the risk of brain metastases?
- Locally advanced non-small cell lung cancer
- Limited-stage small cell lung cancer in complete response (Correct answer)
- Stage III breast cancer
- Glioblastoma multiforme
Correct answer: Limited-stage small cell lung cancer in complete response
PCI is standard of care for patients with limited-stage SCLC who achieve complete response to initial chemoradiation, as the brain is a common sanctuary site. PCI reduces the incidence of brain metastases and improves overall survival in this population.
Question 3: Brachytherapy differs from external beam radiation in that brachytherapy:
- Uses a linear accelerator outside the body
- Places radioactive sources directly inside or adjacent to the tumor (Correct answer)
- Delivers protons rather than photons
- Requires no treatment planning
Correct answer: Places radioactive sources directly inside or adjacent to the tumor
Brachytherapy involves placing sealed radioactive sources (e.g., iridium-192, iodine-125, palladium-103) within or near the tumor. This delivers highly localized doses to the tumor while sparing surrounding normal tissue. It is used for cervical, prostate, breast, and esophageal cancers among others.
Question 4: Which electrolyte imbalance is most commonly seen with severe radiation-induced mucositis and diarrhea?
- Hyperkalemia and hypernatremia
- Hypokalemia, hypomagnesemia, and hyponatremia (Correct answer)
- Hypercalcemia
- Hypermagnesemia
Correct answer: Hypokalemia, hypomagnesemia, and hyponatremia
Severe mucositis and radiation enteritis/diarrhea cause significant electrolyte losses, particularly potassium, magnesium, and sodium. These deficiencies require close monitoring and replacement to prevent cardiac arrhythmias and neuromuscular complications.
Question 5: Osteoradionecrosis is a late complication of radiation most commonly occurring in which anatomical site?
- Femoral head (hip)
- Mandible (jaw) (Correct answer)
- Lumbar vertebral bodies
- Humeral head (shoulder)
Correct answer: Mandible (jaw)
Osteoradionecrosis of the mandible is a severe late radiation complication in patients receiving head and neck radiation. Risk factors include dental extraction in irradiated fields, high cumulative doses, infection, and poor dentition. Prevention includes dental evaluation and extractions before radiation begins.
Question 6: Radiation-induced fatigue is best managed with which evidence-based intervention during active treatment?
- Complete bed rest throughout radiation course
- Moderate aerobic exercise (walking program) (Correct answer)
- High-dose corticosteroids throughout treatment
- Stimulant medications such as methylphenidate daily
Correct answer: Moderate aerobic exercise (walking program)
Evidence consistently supports moderate aerobic exercise (150 min/week of moderate intensity) as the most effective intervention for cancer-related fatigue during and after radiation. Exercise improves energy levels, mood, and quality of life without adversely affecting treatment outcomes.
AOCNP Radiation Therapy Principles and Side Effects 2
A patient receiving radiation to the head and neck develops severe mucositis.
Which intervention is most important for maintaining nutritional status?