Peter H Bisschop1, Eric Fliers1, Tessel M Boertien2, Jan Booij3, Charles B L M Majoie3, Madeleine L Drent4, Alberto M Pereira5, Nienke R Biermasz5, Suat Simsek4,6, Ronald Groote Veldman7, Marcel P M Stokkel8. 1. Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands. 2. Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands. t.m.boertien@amsterdamumc.nl. 3. Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands. 4. Department of Internal Medicine, Section of Endocrinology, Amsterdam UMC, VU University, De Boelelaan 1117, Amsterdam, the Netherlands. 5. Department of Medicine, Division of Endocrinology, and Center for Endocrine Tumors Leiden (CETL), Leiden University Medical Center, Leiden, the Netherlands. 6. Department of Internal Medicine, Northwest Clinics, Alkmaar, the Netherlands. 7. Department of Internal Medicine, Medical Spectrum Twente, Enschede, the Netherlands. 8. Department of Nuclear Medicine, Netherlands Cancer Institute, Amsterdam, the Netherlands.
Abstract
PURPOSE: Clinically 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 111In-DTPA-octreotide scintigraphy in vivo. The aim of this study was to assess SSTR expression in NFMA in vivo using 68Ga-DOTATATE PET, which offers superior sensitivity and spatial resolution as compared with planar scintigraphy or SPECT. METHODS: Thirty-seven patients diagnosed with NFMA underwent 68Ga-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 68Ga-DOTATATE uptake (SUVmean) in the adenoma. An SUVmean of > 2 was considered positive. RESULTS: 68Ga-DOTATATE uptake was positive in 34/37 patients (92%), with SUVmean of positive adenomas ranging from 2.1 to 12.4 (mean ± SD 5.8 ± 2.6). CONCLUSIONS: This is the first report of 68Ga-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 111In-DTPA-octreotide scintigraphy probably reflects the superior sensitivity of PET imaging. TRIAL REGISTRATION: Netherlands Trial Register, NL5136, registered on 18 August 2015; EudraCT, 2015-001234-22, registered on 10 March 2015, https://eudract.ema.europa.eu/.
PURPOSE: Clinically 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 111In-DTPA-octreotide scintigraphy in vivo. The aim of this study was to assess SSTR expression in NFMA in vivo using 68Ga-DOTATATE PET, which offers superior sensitivity and spatial resolution as compared with planar scintigraphy or SPECT. METHODS: Thirty-seven patients diagnosed with NFMA underwent 68Ga-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 68Ga-DOTATATE uptake (SUVmean) in the adenoma. An SUVmean of > 2 was considered positive. RESULTS:68Ga-DOTATATE uptake was positive in 34/37 patients (92%), with SUVmean of positive adenomas ranging from 2.1 to 12.4 (mean ± SD 5.8 ± 2.6). CONCLUSIONS: This is the first report of 68Ga-DOTATATE PET performed in NFMApatients, demonstrating in vivo SSTR expression in the vast majority of cases. The high positivity rate when compared with results obtained with 111In-DTPA-octreotide scintigraphy probably reflects the superior sensitivity of PET imaging. TRIAL REGISTRATION: Netherlands Trial Register, NL5136, registered on 18 August 2015; EudraCT, 2015-001234-22, registered on 10 March 2015, https://eudract.ema.europa.eu/.
Authors: F Gabalec; M Drastikova; T Cesak; D Netuka; V Masopust; J Machac; J Marek; J Cap; M Beranek Journal: Physiol Res Date: 2014-12-22 Impact factor: 1.881