Dosimetry from Scans : The estimated dosimetry has been calculated for the scans that will be 
performed. 
a. Estimated Dosimetry: Tc-99m-pyrophosphate 
Dosage and Route: 0.25 mCi by inhalation 
Target organ absorbed dose: 
Assumption 1: Uniform lung distribution 
Whole body - approximately 0.003 mCi 
Lungs - approximately 0.050 mCi 
Assumption 2: All aerosol in trachea and larger bronchi 
Whole body - approximately 0.003 mCi 
Bronchial epithelium - approximately ? 
b. Dosimetry: Thin section CT of the lung 
(1.5 mm thick sections at 10 cm intervals) 
Six sections to be acquired 
Dosimetry: Tc-99m macroaggregated albumin (MAA) 
Whole body 
rad/2 mCi 
0.024 
Lungs 
0.40 
Liver 
0.065 
Spleen 
0.034 
Kidneys 
0.022 
Bladder wall 
0.24 
Testes 
0.013 * 
Ovaries 
0.020 * 
4.8 hr void 
Source: Package insert, AN-MAA, Bedford MA: CB US, Inc, 1988. 
The patients participating in this study will be adults aged 18 years or more, with mild to 
moderate cystic fibrosis lung disease. The median survival age of these patients is currently 29 
years. The proposed study is a phase I study, so there will be no long-term benefits to the 
patients involved in the experimental protocol. However, the study could have considerable 
benefit to cystic fibrosis patients in general and to the study participants, in the long term. The 
information gained by the study will provide critical information for the development of gene 
therapy and a possible cure for cystic fibrosis pulmonary disease. We therefore feel that the 
radiation dose is safe and acceptable for the study participants. 
Social Isolation: The patients in this protocol will be in respiratory isolation for approximately 
4 weeks. During this time they will have a television and VCR available for entertainment. 
They will be allowed visitation by family members, who will be required to follow the 
respiratory isolation procedures. We will provide the patients with an exercise bicycle to allow 
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Recombinant DNA Research, Volume 17 
