68Ga-DOTANOC PET/CT allows somatostatin receptor imaging in idiopathic pulmonary fibrosis: preliminary results

V Ambrosini, M Zompatori, F De Luca… - Journal of Nuclear …, 2010 - Soc Nuclear Med
V Ambrosini, M Zompatori, F De Luca, V Allegri, C Nanni, D Malvi, E Tonveronachi…
Journal of Nuclear Medicine, 2010Soc Nuclear Med
Interstitial lung diseases include different clinical entities with variable prognoses. Idiopathic
pulmonary fibrosis (IPF), the most common, presents the most severe outcome (death within
3–5 y), whereas nonspecific interstitial pneumonia (NSIP) shows a more indolent
progression. Preclinical evidence of somatostatin receptor (SSTR) expression on fibroblasts
in vitro and in lung fibrosis murine models, coupled with the longer survival of mice with
fibrotic lungs treated with agents blocking SSTR, supports the hypothesis of imaging …
Interstitial lung diseases include different clinical entities with variable prognoses. Idiopathic pulmonary fibrosis (IPF), the most common, presents the most severe outcome (death within 3–5 y), whereas nonspecific interstitial pneumonia (NSIP) shows a more indolent progression. Preclinical evidence of somatostatin receptor (SSTR) expression on fibroblasts in vitro and in lung fibrosis murine models, coupled with the longer survival of mice with fibrotic lungs treated with agents blocking SSTR, supports the hypothesis of imaging fibroblast activity in vivo by visualization of SSTR with 68Ga-DOTANOC PET/CT. The aim of this study was to evaluate 68Ga-DOTANOC PET/CT in patients with IPF and NSIP.
Methods
Seven IPF patients and 7 NSIP patients were included in the study. 68Ga-DOTANOC PET/CT and high-resolution CT (HRCT) were performed in all cases by following a standard procedure. PET/CT results were compared with disease sites and extent on HRCT.
Results
In IPF, 68Ga-DOTANOC uptake was peripheral, subpleural, and directly correlated with pathologic areas on HRCT (subpleural/reticular fibrosis, honeycombing). NSIP patients showed fainter tracer uptake, whereas corresponding HRCT showed areas of ground-glass opacity and rare fibrotic changes. Only IPF patients showed a linear correlation between maximal SUV and disease extent quantified both automatically (Q) (IPF: P = 0.002, R = 0.93) and using the visual score (Spearman ρ = 0.46, P = 0.0001). Q directly correlated with percentage carbon monoxide diffusing capacity in IPF (P = 0.03, R = 0.79) and NSIP (P = 0.05, R = 0.94), whereas maximal SUV did not present any correlation with percentage carbon monoxide diffusing capacity.
Conclusion
Our preliminary data show that 68Ga-DOTANOC PET/CT demonstrates SSTR overexpression in IPF patients; this may prove interesting for the evaluation of novel treatments with somatostatin analogs.
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