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

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 (SUV_mean) in the adenoma. An SUV_mean of > 2 was considered positive.

Results

⁶⁸Ga-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).

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/.

SUBMITTER: Boertien TM 

PROVIDER: S-EPMC8218160 | biostudies-literature |

REPOSITORIES: biostudies-literature