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863.e2 Radiation Therapy: Adverse Reactions

Radiation Therapy: Adverse Reactions Client Education
Sheet
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of pliability/flexibility/range of motion,
BASIC INFORMATION
pain, dry desquamation, chronic wound • Cytokines induced immediately after irradia-
tion have been shown to contribute to the
Definition • Head/neck effects progression of chronic effects and chronic
Radiation reactions are considered acute if they ○ Acute: stomatitis, mucositis, pharyngitis, inflammatory syndromes.
occur during or shortly after radiation therapy esophagitis (erythema, edema, confluent
(RT) and subside in 2-3 months after therapy. or patchy white/yellow membrane forma- DIAGNOSIS
Reactions with clinical signs persisting over a tion), xerostomia, cheilosis, ulceration,
longer period or occurring months to years pain, dysphagia, secondary infection Differential Diagnosis
after treatment are considered chronic or latent. with bacteria or fungi, lip smacking/ Infection; progression or recurrence of tumor
cracking, affected taste, swelling of
Synonyms parotid/submandibular salivary glands, Initial Database
Radiation complications, radiation side effects keratitis, keratoconjunctivitis sicca, blepha- • Minimal database to rule out metabolic
rospasm, periocular crusting, corneal contribution to complications
Epidemiology edema • Diagnostic imaging (radiographs, CT, MRI,
SPECIES, AGE, SEX ○ Chronic: osteonecrosis (bone pain, swell- positron emission tomography) to determine
Any patient treated with radiation is at risk. ing, evidence of infection, exposed bone, extent/nature of disease
nonhealing gingival ulcers), xerostomia, • Biopsies if necessary to differentiate tumor
RISK FACTORS regurgitation, dental caries, tooth discol- recurrence or infection from radiation
• Radiation dose, fractionation, energy, overall oration, keratoconjunctivitis sicca, cataract reaction
treatment time, field size, previous surgery, formation, retinitis, blindness • Clinician-based assessment: Veterinary Radia-
concurrent administration of chemotherapy, • Bone effects (chronic): clinical/radiographic tion Therapy Oncology Group (VRTOG)
and necrotic, infected, or unhealthy tissues evidence of fracture, necrosis, infection, or acute/chronic radiation scoring scheme (see
may influence a patient’s risk for the develop- secondary tumor Suggested Readings)
ment of adverse radiation reactions. Cats are • Heart effects (acute/chronic): signs related
less likely to have adverse radiation reactions to pericarditis, chronic constrictive pericar- Advanced or Confirmatory Testing
than dogs. ditis, or restrictive cardiomyopathy due to Generally not necessary; in people:
• Site-specific risk factors include myocardial fibrosis, such as fever, tachycardia, • Chronic skin fibrosis measured by tissue
○ Skin: presence of skin folds, tangential presence of pericardial effusion, cardiac compliance meter, ultrasound measurement,
radiation fields, poor nutrition, individual tamponade, pleural effusion, dyspnea, con- or BTC-2000 suction device
differences, use of radiation bolus, use of duction abnormalities, exercise intolerance, • Xerostomia measured by functional radio-
electron therapy, coincident infection subclinical valvular defects isotope imaging, salivary flow output, and
○ Head/neck: periodontal disease, coincident • Bladder effects (acute/chronic): pain on patient assessment
infection, concurrent xerostomia (dry palpation, cystitis • Pulmonary function tests for confirmation
mouth, inadequate saliva production) • Lung effects (acute/chronic): clinical and of decreased lung capacity
○ Heart: doxorubicin treatment, valvular radiographic signs compatible with acute
stenosis pneumonitis and chronic fibrosis (fever, TREATMENT
dyspnea, cough, production of sputum,
Clinical Presentation signs of right heart failure if pulmonary Treatment Overview
DISEASE FORMS/SUBTYPES hypertension exists); fibrosis usually, but • Improving patient quality of life by minimiz-
• Acute effects occur during or immediately not always, preceded by pneumonitis ing pain, establishing return to function, and
after RT and depend on total dose, dose per • Colon/rectal effects (acute/chronic): diarrhea ruling out tumor recurrence
fraction, and overall treatment time. secondary to acute enteritis, hematochezia, • Amelioration of acute side effects may
• Chronic effects occur months to years after sense of urgency, chronic diarrhea, inconti- decrease risk of chronic side effects.
RT and depend highly on dose per fraction. nence, proctitis, stricture, fistula formation
secondary to chronic colorectal/anorectal Acute General Treatment
HISTORY, CHIEF COMPLAINT injury • Skin effects
Complaints are typically related to the physical • Central nervous system effects (acute/ ○ Protect irradiated skin from heat, cold,
exam findings listed below and occurring within chronic): signs compatible with location of sunlight, friction, and other sources
the RT field. radiation field (neurologic deficits, seizures, of irritation; apply SPF 15 or greater
ataxia, blindness, paralysis, dementia, som- sunscreen on intact skin.
PHYSICAL EXAM FINDINGS nolence, endocrinopathies) ○ Avoid use of tape.
All physical exam findings are directly related to ○ Cleanse irradiated area daily using water,
tissues in the RT field and are usually confined Etiology and Pathophysiology normal saline, or mild soap solution.
to limits of the treatment field. • Radiation lesions induced in normal tissues ○ Cleanse/irrigate moist desquamation with
• Skin effects are attributed primarily to loss of specific aluminum subacetate (Domeboro) soaks,
○ Acute: erythema, hyperpigmentation, dry target cells or clonogenic cells. Acute effects one-third strength hydrogen peroxide
desquamation, moist desquamation, ulcer- predominate in rapidly renewing tissues such (1%).
ation, necrosis, hair loss, lymphedema, as skin, gastrointestinal (GI) tract, or bone ○ Use of skin care products is anecdotal, but
pain marrow. they include Aquaphor, Collasate, vitamin
○ Chronic: RT field pain, telangiectasia, • This target cell theory also applies to vascular A/D ointment, aloe vera gel, TheraCare,
fibrosis, necrosis, lymphedema, hyper- damage as the predominant lesion in chronic 1% hydrocortisone ointment, silver
pigmentation or hypopigmentation, effects because endothelial cells are slowly sulfadiazine, Miaderm, Biafine, Radioplex,
leukotrichia (whiteness of the fur), loss lost to mitotic death. and Carrasyn.

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