A. Nutritional support
Nutritional support during radiation therapy is vital for the prevention of cachexia, immune compromise, and inability to repair normal tissue damage.
1. Nutritional status needs to be assessed initially.
a. Weight loss probably indicates negative nitrogen balance, which must be corrected.
b. Counsel the patient and family regarding unusual or idiosyncratic dietary habits, to assure a nutritionally complete diet.
Caloric need duri ng radiation therapy is approximately 11096 of baseline.
An enteral diet is preferable to a parenteral diet.
a. Oral diet modifications may be necessary.
i. Taste may change secondary to the tumor or to treatment, which may alter diet.
ii. If the mucosa of the upper gastrointestinal tract is being irradiated, a soft, bland diet may be required (no spicy, acidic, or hot or cold food or drink).
iii. Standard oral supplements must be used if caloric requirements cannot be met otherwise (e.g., Sustacal, Ensure, or Carnation Instant Breakfast).
b. Nasogastric tube feeding is probably required if 1096 weight loss occurs during treatment.
4. Intravenous hyperalimentation is indicated if the patient is unable to tolerate oral or nasogastric feeding.
B. Management of hem atologic and immunologic toxicity Radiation therapy of any part of the body can suppress blood counts, particularly white blood cells and platelets.
Patients who have received chemotherapy, previously or concurrently, or whose treatment volume encompasses a significant percentage of marrow are at particular risk.
Follow protocol guidelines for interruption of therapy due to hematologic toxicity.
In the absence of protocol guidelines, consider the rate of decrease in counts and clinical situation; consider holding treatment for absolute neutrophil count <1000 cells/pL or platelets < 75,000.
The role of colony-stimulating factors during radiation therapy is not yet established.
C. Management of radiation-induced nausea and vomiting
Radiation-induced nausea and vomiting can be difficult to prevent. Nausea can be seen with radiation of the head or stomach; occasionally it is also seen when other parts of the body are irradiated. The mechanisms are different, so the treatments are different.
Management of nausea and vomiting due to cranial irradiation (see below, “Side Effects of Cranial Irradiation.”)
Management of nausea and vomiting due to direct effect on the stomach
a. Etiology: not well understood
b. Treatment
i. Sipping of decarbonated cola drinks may relieve
ii. Antiemetic medications
(1) Prochlorperazine (Compazine)
(a) Dose:
Children (>10 kg or >2 years): 0.4 mg/kg/day, by mouth (PO) or per rectum, divided t.i.d.q.i.d.
Teenagers: 5-10 mg per dose t.i.d. to q.i.d.
(b) Available:
Tablet: 5, 10, or 5 mg Syrup: 5 mg/mL Suppository: 2.5, 5, or 25 mg
(2) Metoclopromide (Reglan)
Dose: 0.1 mg/kg PO q.i.d.
Available: tablet: 5 or 10 mg Syrup: 5 mg/mL
(3) Cisapride (Propulsid)
Dose: children: 0.2-0.3 mg/kg per dose PO t.i.d. to q.i.d.
Tablet: 10 cor 20 mg Suspensions: 1 mg/mL (4) Ondansetron (*Zofran)
(a) Dose: 0.15 nmg/kg per dose; usually adminis-
tered PO p4-6h, starting 1 hour before
radiation d;.aily.
(b) Available: ts ablet: 4 or 8 mg
3. Management of nausea and vomiting due to radiation of other parts of body
a. Etiology
This is believed to be due to delayed gastric emptying.
b. Treatment
Cisapride (PropulsidH) and metoclopramide (Reglan) may have physiologic advantages by promoting gastric emptying.
A. Growth problems
1. Neuroendocrine effect of irradiation of hypothalamic pitu-
itary axis
2. Direct effect on irradiateed bone and soft tissue
a. Effect is age and doses dependent.
i. Irradiated bones may be smaller or shorter than
nonirradiated bonaes.
ii. Spinal irradiation imay affect height and may exacer-
bate kyphosis or sscoliosis.
b. Irradiated muscle may atrophy.
3. Management of growth problems
a. Consider growth horanone replacement.
b. Monitor for scoliosis and kyphosis.
c. Consider early plastic surgical intervention to correct
facial deformities, sutfficient to cause psychosocial dis-
d. Offer psychosocial support
B. Soft tissue fibrosis over a joint
1. Etiology
This is caused by scarr-ing after high-dose radiotherapy. The risk is increased if the field also includes a radical surgical site.
2. Prevention
If possible, plan surgical incisions to allow the radiation oncologist to avoid treating a full joint.
3. Treatment
Daily range-of-motion exercises for the rest of the patient’s life will be necessary.
C. Peripheral edema
1. Etiology
a. Lymphatic obstruction
b. Venous insufficiency
2. Prevention
Place incisions vertically, not transversely, in extremities, to allow the radiation oncologist to treat the entire scar without treating the entire circumference of the extremity.
D. Carcinogenesis
1. Risk factors for second malignant neoplasm due to radiation therapy
a. The relative risk of a second malignant neoplasm due to radiation therapy is not yet well defined, as it varies from report to report and by original disease, age at treatment, and site treated.
b. Children treated for one malignancy have an increased risk of developing a second malignant neoplasm, even in the absence of radiation therapy.
c. Genetics (heredity) plays a role.
i. Patients with basal cell nevus syndrome often develop basal cell cancers in the irradiated field 6 months to 3 years after treatment.
ii. Patients with familial retinoblastoma are at increased risk of a second malignant neoplasm, even without irradiation.
d. About two-thirds of second malignant neoplasms are found in the field of radiation therapy. Bone and soft tissue sarcomas are considered radiation induced only if they occur in the radiated treatment volume.
e. Tissue sensitivity to carcinogenesis from radiation varies.
i. Thyroid gland and breast are at risk after low doses.
ii. Lung, liver, and lymphoid tissue are at risk after moderate doses.
iii. Bone and muscle are at risk after higher doses.
f. Tissue stage of development alters risk; proliferating cells are most at risk. Girls whose breast tissue is irradiated between ages 10 and 16 (during pubertal development) have the greatest increase in risk of developing breast cancer; risk declines as the age at treatment
g. Sex is a factor. The risk of a second malignant neoplasm is higher for females than males, even excluding breast cancer.
2. Management
a. Discourage smoking in survivors, especially if the respiratory tract has been irradiated.
b. Examine tissues at risk, i.e., those in radiation treatment volume.
c. Perform scrupulous breast follow-up for women who received radiation to the breast during adolescence.
i. Monthly breast self-examination
ii. Regular clinical breast examinations; early annual mammography (exact age to start is controversial)
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