RADIATION CHANGE IN NORMAL ORGANS - AN OVERVIEW OF BODY IMAGING

Radiotherapy causes changes in a treated malignancy and the surroundin g normal tissue which must be included in the radiation fields. Awaren ess of the expected appearance of these changes frequently permits dif ferentiation of them from superimposed infection, recurrent malignancy , radiation-induced tumors, and the other true complications of radiat ion therapy. Radiotherapy changes are a function of the tissue volume treated, field shape, total dose and how it was delivered, time from c ompletion of therapy, and the possible effect of other therapies. Timi ng of radiation changes varies in the different organs. Acute radiatio n pneumonitis is generally seen approximately 2 months after completio n of radiotherapy but radiation pericarditis not until 6-9 months afte r therapy Radiation-induced sarcomas do not develop on average until 1 0-15 years after radiation therapy. An overview of expected findings a nd complications in the lungs, heart, gastrointestinal tract, genitour inary tract, and bones is presented.