Value of67gallium scintigraphy in primary diagnosis and follow-up of opportunistic pneumonia in patients with AIDS

Abstract

Opportunistic pneumonias are a life-threatening complication in patients with AIDS. Early diagnosis and therapy is necessary to improve the prognosis. This study was designed to assess the value of 67gallium scintigraphy in the primary detection and follow-up of these special pneumonias. 67Gallium scintigraphy was performed in 40 patients: 10 normal controls and 30 HIV-positive patients with AIDS or AIDS-related complex (ARC). 67Gallium scan results were compared with current chest x-rays and the results of pathogen detection. The evaluation of positive scans was based on a quantification of the pulmonary uptake, expressed as a pulmonary/soft tissue uptake ratio. Only 8 of 30 patients had a normal scan, while 22 of 30 showed diffuse (13/22) or focal (9/22) increases of pulmonary uptake. In seven of eight patients with normal scans the chest radiograph was negative as well. The one patient with negative scan but positive chest radiograph had pulmonary Kaposi's sarcoma. In 11 of 22 patients, the 67gallium scan and chest x-ray were positive simultaneously. In the other 11 of 22 patients with positive scans, chest radiographs were initially negative but showed pathology in five cases within 1-2 weeks. The reason for positive scans in most cases was an opportunistic lung infection; other forms of pneumonia were observed only in two cases. The defined uptake ratio was demonstrated to be a highly sensitive parameter for monitoring pneumonia and the effects of therapy in follow-up studies. In conclusion, quantitative 67gallium scintigraphy proved to be a reliable and highly sensitive method for primary detection and follow-up of opportunistic pneumonias in patients with AIDS.