Gallium-67 scanning in the staging of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis

Abstract

Gallium-67 citrate is known to localize within inflammatory sites. Gallium-67 scanning is used for the evaluation of lung inflammation (i.e. alveolitis) during interstitial lung diseases. We investigated 27 patients with cryptogenetic fibrosing alveolitis (n = 17) and hypersensitivity pneumonitis (n = 10) using gallium-67 lung scanning and lung function tests (forced vital capacity, diffusing capacity, resting and exercise blood gases). Investigations were performed before and after one year of methylprednisolone treatment. None of eight healthy volunteers had any abnormal gallium-67 uptake. In all patients with cryptogenetic fibrosing alveolitis an initial abnormal gallium-67 uptake was observed (mean fixation index: 163 +/- 18). In addition, analysis of lung function tests a year after initial evaluation showed that unchanged or improving patients presented initially with a lower gallium-67 index than patients with evidence of deterioration (153.9 +/- 23.7 vs 251.0 +/- 23.3.; p less than 0.01). Similarly, among patients with hypersensitivity pneumonitis the index was lower in unchanged or improving patients than in those with deterioration (74.9 +/- 22 vs 226.7 +/- 4.9; p less than 0.05). Thus gallium-67 scanning is useful in the management of cryptogenetic fibrosing alveolitis and hypersensitivity pneumonitis.