Absolute quantitation of gallium-67 citrate accumulation in the lungs and its importance for the evaluation of disease activity in pulmonary sarcoidosis

Abstract

Our modification of a method for the absolute quantification of gallium-67 uptake in lungs with a scintillation camera and computer is described. The uptake of 67Ga in lungs, expressed in percentage of administered radioactivity, was determined by the transmission-emission method. We proved theoretically and experimentally that a 67Ga planar source could be replaced with a 57Co planar source. The performance of lung perfusion scans allows a more accurate delineation of the regions of interest on gallium scans. The method was applied to control subjects (n = 27) and to patients (n = 114) suffering from biopsy-proven pulmonary sarcoidosis (28 with inactive and 86 with active disease). The obtained results were compared with chest X-ray findings, the percentage of lymphocytes in the bronchoalveolar fluid (BAF-ly%), and serum angiotensin-converting enzyme (SACE) values. The method seems suitable for the assessment of disease activity in sarcoidosis. It is more accurate in detecting parenchymal involvement in lung sarcoidosis than the commonly used X-ray criteria. No correlation was found between 67Ga uptake and the BAF-ly% and SACE values.

Significance of lymphocytosis in bronchoalveolar lavage in suspected ocular sarcoidosis

“…Since Ga is taken into macrophages or epithelioid cells, a Ga scintigram is not positive without granuloma formation. There are some reports that the Ga scintigram is useful for detecting granuloma [23,24] in comparison with other examinations, but in this study HRCT was more sensitive and specific for the early detection of sarcoidosis ( fig. 2).…”

Lacrimal Gland Uptake of67Ga-gallium Citrate Correlates with Biopsy Results in Patients with Suspected Sarcoidosis

“…31,32 Several computer-aided methods for quantifying pulmonary gallium uptake have been reported for assessing pulmonary disease activity in sarcoidosis. 12,[33][34][35][36][37][38][39] For example, Brantley et al found that parotid gland biopsy yield was marginally higher in those with abnormal gallium parotid uptake. 40 To our knowledge, little research has been done to quantify uptake in the lacrimal gland 10 and no study has correlated biopsy results with the intensity of gallium uptake in the lacrimal region.…”

Radionuclide Studies of the Lung

“…Gallium uptake may be considered as a bioassay of the activity of a known inflammatory process (acute versus chronic or quiescent inflammation; response of sepsis to treatment, etc.) (2). Low grade, welldifferentiated tumors often have lower gallium affinity ("false negative"), which is a good prognostic sign (3).…”