[Differentiation of infiltrates between lung cancer and noncancerous lung disease by 123I-IMP lung imaging].

Lung imaging with N-isopropyl-p-123I-iodoamphetamine (123I-IMP) was performed to estimate the pulmonary lesion imaging findings in 3 patients with bronchogenic carcinoma (2: bronchioloalveolar carcinoma and 1: adenocarcinoma) and 18 with noncancerous lung diseases (10: bacterial pneumonia, 1: viral pneumonia, 1: aspiration pneumonia, 1: radiation pneumonitis, 4: pulmonary tuberculosis and 1: obstructive pneumonitis due to an endobronchial lipoma) at 30 min and 4 hr after i.v. injection of 111 MBq of 123I-IMP. These patients all exhibited infiltrates only in the chest radiograms. Decreased uptake of 123I-IMP was observed in the cancerous infiltrating lesions in 3 patients with bronchogenic carcinoma at 30 min and 4 hr, while the uptake of 123I-IMP was normal or increased at 30 min and intense at 4 hr in all 18 noncancerous infiltrating lesions. Therefore 123I-IMP lung imaging can be used to differentiate bronchogenic carcinoma from noncancerous lung disease in patients who exhibit infiltrates only in the chest radiograms.