CONTAMINATION OF THE PLEURAL SURFACES IN CHILDHOOD SARCOMA - USE OF COLLOIDAL P-32 TO REDUCE RADIATION-DOSE TO THE WHOLE LUNG

Children with pulmonary sarcomas who have diffuse contamination of the pleural cavity present a difficult management problem for the radiati on oncologist. Doses required to control even microscopic disease exce ed lung tolerance. We report on the use of intracavity colloid P-32 in an attempt to treat the pleural surface and spare normal lung parench yma and tissues of the chest wall. Three children-18 months, 12 years, and 3 years of age-had spillage of pulmonary sarcomas into the chest cavity. All children were treated with systemic chemotherapy. Initiall y, 0.5 mCi of technetium sulfur colloid (Tc-99m-sulfur colloid) was in stilled into the pleural space to ascertain even distribution of isoto pe. This was then followed by installation of 5.0 mCi of colloidal P-3 2. Uniform distribution was then confirmed by bremsstrahlung scanning. All three patients are in complete remission 3.5 years, 3 years, and 1 year after treatment, respectively. The major toxicity was asymptoma tic pleural thickening, which could be confused with disease. This was confirmed histologically to be fibrous in the first patient. The proc ess diminished or stabilized with time in all 3 patients over the peri od of observation. In this small series, intrapleural colloidal P-32 a ppeared to be safe and well tolerated and would be expected to be less toxic than wide-field external beam in the treatment of spilled pulmo nary sarcomas.