Radiation Therapy Principles and Side Effects Flashcards

A patient receiving radiation to the head and neck develops severe mucositis. Which intervention is most important for maintaining nutritional status?

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.

Prophylactic cranial irradiation (PCI) is standard of care for which cancer type to reduce the risk of brain metastases?

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.

Brachytherapy differs from external beam radiation in that brachytherapy:

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.

Which electrolyte imbalance is most commonly seen with severe radiation-induced mucositis and diarrhea?

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.

Osteoradionecrosis is a late complication of radiation most commonly occurring in which anatomical site?

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.

Radiation-induced fatigue is best managed with which evidence-based intervention during active treatment?

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.