BACKGROUND: Positron emission tomography (PET) combined
with computer tomography (CT) using 68Ga-DOTATATE
is a promising method for the evaluation of patients with recognised
or suspected neuroendocrine tumours (NET). The aim of
this study was to assess the diagnostic value of 68Ga-DOTATATE
PET/CT in the visualisation of the expression of somatostatin
receptors (SSTR) and identification of new lesions.
MATERIAL AND METHODS: Between December 2009 and
January 2011 ninety-seven patients with confirmed (88 cases)
or suspected (9 cases) NET underwent 68Ga DOTATATE
PET/CT. The primary, confirmed or suspected, NET localizations
were: GEP tumours — 71 patients; medullary thyroid
carcinoma — 4 patients; cancer of an unknown primary — 14
patients; and NET in other localisations — 8 patients. PET/CT
acquisitions were performed using standard techniques, 45 to 60 minutes after the intravenous injection of 111–185
MBq 68Ga-DOTATATE.
RESULTS: 68Ga-DOTATATE PET/CT detected the presence of
lesions demonstrating the somatostatin receptor affinity in 50 of
the 97 patients (51.5%) and was negative in 47 patients (48.5%).
Among 14 patients with metastatic unknown primary cancer, in
5 patients (45.5%) the primary tumour site was identified, and
in 4 patients with medullary thyroid cancer distant metastases
with SSTR expression were localized in only one patient.
CONCLUSIONS: Our findings confirm the diagnostic role of
68Ga-DOTATATE PET/CT as an accurate method of identifying
primary tumours and distant metastases. It provides information
on tumour cell receptors status, which has a significant
bearing on planning target radionuclide therapy. Overall,
68Ga-DOTATATE PET/CT can be used in staging, re-staging,
and in regular follow up of oncology patients.
Nuclear Med Rev 2011; 14, 1: 16–2