68 Ga-DOTATATE PET imaging in clinically non-functioning pituitary macroadenomas

摘要

PurposeClinically non-functioning pituitary macroadenomas (NFMA) have been reported to express somatostatin receptors (SSTR), but results are inconsistent across different studies. This may be related to limited sensitivity and specificity of techniques used to date, i.e. immunohistochemistry in surgical specimens and 111 In-DTPA-octreotide scintigraphy in vivo. The aim of this study was to assess SSTR expression in NFMA in vivo using 68 Ga-DOTATATE PET, which offers superior sensitivity and spatial resolution as compared with planar scintigraphy or SPECT.MethodsThirty-seven patients diagnosed with NFMA underwent 68 Ga-DOTATATE PET/CT of the head in the framework of a randomised controlled trial assessing the effect of the somatostatin analogue lanreotide on NFMA size. Individual co-registered T1-weighted pituitary MRIs were used to assess 68 Ga-DOTATATE uptake (SUV mean ) in the adenoma. An SUV mean of ?2 was considered positive.Results 68 Ga-DOTATATE uptake was positive in 34/37 patients (92%), with SUV mean of positive adenomas ranging from 2.1 to 12.4 (mean?±?SD 5.8?±?2.6).ConclusionsThis is the first report of 68 Ga-DOTATATE PET performed in NFMA patients, demonstrating in vivo SSTR expression in the vast majority of cases. The high positivity rate when compared with results obtained with 111 In-DTPA-octreotide scintigraphy probably reflects the superior sensitivity of PET imaging.