Health Physics Aspects of 133Xe Lung Studies

Abstract

A b~t r a c t L~~X e gas is currently being used for a variety of lung scanning studies in the evaluation ofpatients with pulmonary disease. This radionuclide was selected for a number of reasons: (1) it does not react chemically with body tissues; (2) its physical half-life is such that useful quantities can be supplied from distant sources; (3) its biological half-life is in the order of minutes and the absorbed dose to the patient, even from millicurie amounts, is minimal; (4) only nominal shielding is required for the X and gamma emissions; and (5) commercial dose calibrators are available, which express activity directly in mCi or pCi.In the chain of transfers necessary from receipt of the radioactive gas to final disposal of waste, leakage must be continually guarded against. In our experience over several years, leakage, when it has occurred, has most often been caused by excessive strain on connecting lines.However, film badge exposures for personnel involved have been consistently minimal and no overexposures have occurred, although we have handled as much as 2 Ci per month. Accident pre-planning, including careful consideration of containment and dispensing apparatus, ventilation and exhaust requirements, and dry runs, have contributed to this record.