Lung Cancer.pdf

Prevention and Management of Sequelae of Multimodality Therapy 245
Radiation Oncology
Acute Side Effects
The most common acute side effects of external-beam irradiation are skin
reactions, esophagitis, anorexia, nausea, and fatigue. Other acute side effects,
such as pneumonitis and pericarditis, are possible but occur infrequently.
Skin reactions after radiation therapy range from mild erythema localized
within the treatment portal to moist desquamation. When the skin is
intact, these changes are managed with an emollient moisturizer such as
Aquaphor ointment. A thin layer of this hydrogenated petrolatum is applied
to the affected skin area daily after radiation therapy. It is important
for patients to understand that applying a moisturizer prior to a radiation
treatment may actually intensify the reaction. In cases in which the skin
has sloughed, a half-strength diluted solution of 3% hydrogen peroxide
solution and water is applied with gauze to clean away dead skin and reduce
the risk of superinfection. This cleansing is followed by application
of 1% hydrocortisone cream to reduce inflammation and pruritus. Silvadene
cream can also be used. For more severe reactions, particularly
those involving a large area of desquamation, an occlusive dressing is applied
to provide a moisture barrier until the new epithelial layer forms,
though this requires stopping radiation therapy until the desquamation
resolves or removing the dressing prior to each radiation treatment.
Esophagitis is the major dose-limiting side effect of thoracic irradiation.
Even with conformal treatment planning and treatment delivery, a portion
of the esophagus receives a significant radiation dose during pulmonary
irradiation. After 2 to 3 weeks of conventional daily radiation
treatments, patients develop mild dysphagia. Reactions earlier than this
usually represent thrush or gastroesophageal reflux and should be treated
with antifungals or H2 blockers, respectively. Often patients will describe
not pain but rather a glomus sensation or a feeling that food is sticking in
place. This discomfort usually responds to analgesic therapy. A topical
agent such as viscous lidocaine alone or in a mouthwash preparation with
diphenhydramine and aluminum hydroxide or magnesium hydroxide
suspension can provide immediate relief, especially if the agent is applied
before meals. Sucralfate (Carofate) slurries can also be used. Many patients
respond well to combination analgesics, such as hydrocodone and
acetaminophen, taken before meals and bedtime. As odynophagia progresses,
elixir formulations are often better tolerated than tablets. For
more refractory cases of odynophagia, narcotics such as morphine or oxycodone
are used. Time-release formulations are given twice daily and supplemented
with smaller doses of the immediate-release preparation given
as needed for breakthrough pain. This approach allows rapid, effective
dose titration to meet patients’ analgesic needs. Transdermal fentanyl is
used for patients who have difficulty managing multiple medication
doses. Potential disadvantages of transdermal fentanyl include longer