Radiation Therapy Factors

Certain collagen vascular diseases, such as scleroderma and systemic lupus erythematosus, have been associated with an increase in acute skin and subcutaneous toxicity to standard doses of radiotherapy and may be related to inadequate repair of sublethal radiation injury. However, a retrospective review of patients with collagen vascular disease showed that only patients with scleroderma exhibited prohibitive toxicity. Patients with other collagen vascular diseases did not experience prohibitive toxicity and could be considered candidates for BCT.58 The potentially deleterious effects of radiotherapy on the developing fetus prohibit patients in the first two trimesters of pregnancy from being candidates for BCT. Estimated cumulative fetal doses of 3 to 4 Gy are delivered with tangential radiotherapy.59 Because there is no known threshold dose for mutagenesis, radiotherapy is an absolute contraindication during the first two trimesters. Long-term effects of radiation during the third trimester are unclear.

0 0

Post a comment