Evaluating the possible role of 68Ga-citrate PET/CT in the characterization of indeterminate lung lesions.

UNLABELLED We sought to determine whether PET/CT imaging with (68)Ga-citrate could be of value in distinguishing benign from malignant lung pathology in a setting with a high prevalence of granulomatous diseases. METHODS Thirty-six consecutive patients with indeterminate lung lesions prospectively underwent dual time point (60 and 120 min) (68)Ga-citrate PET/CT study prior to lung biopsy. Qualitative and semi-quantitative measures of tracer uptake in the lung lesions (SUVmax) were compared to the histopathology in order to establish an imaging pattern to distinguish benign from malignant lesions. RESULTS Fourteen patients (38.9 %) were diagnosed with a malignant lesion, 12 (33.3 %) with tuberculosis (TB), and 10 participants (27.8 %) with other benign lung lesions. At 60-min post-injection, patients who were diagnosed with a malignant lesion (n = 14) demonstrated a mean SUVmax of 3.36 ± 1.14, with a median value of 3.04 (min = 1.56, max = 4.65).Those with TB (n = 12) demonstrated a SUVmax of 3.99 ± 2.28, and a median value of 3.71 (pct25 = 2.19, pct75 = 4.95). In patients with other benign lesions (n = 10), the following values were observed: a SUVmax of 2.70 ± 1.31, a median value of 2.50 (pct25 = 1.76, pct75 = 3.59). The mean values of these three types of pathology were not statistically significant (p = 0.1919), and therefore the SUVmax could not be used to accurately distinguish between these lesions using both early and delayed imaging. CONCLUSION This study, as the first (68)Ga-citrate PET/CT in humans for the in vivo imaging of lung pathology, demonstrated its potential for the detection of both malignancy and TB. However, (68)Ga-citrate seemed incapable of providing a clear distinction between malignant and benign lung lesions in a setting with a high prevalence of granulomatous diseases such as TB.