Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Sebestyen, E.
Diagnostic value of 68Ga-DOTA-NOC PET/CT in patients with neuroendocrine tumours of the pancreas: a retrospective study
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2019. pp. 60
[OPEN ACCESS]
FullText
- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Stanzel Susanne
- Altmetrics:
- Abstract:
- Objective The aim of this retrospective study is to evaluate the diagnostic value of 68Ga-DOTA-NOC PET/CT in patients with histologically confirmed neuroendocrine tumour of the pancreas (pNET). Methods 68Ga-DOTA-NOC PET/CT scans of thirty patients with proven pNETs were evaluated. The tracer uptake in the pancreas and distant lesions were quantified and compared by measuring the maximum standardized uptake value (SUVmax). A cut-off value of SUVmax to differentiate between physiological and pathological tracer-uptake in the pancreas was obtained by using ROC-analysis. PET/CT scans were analysed in terms of detected lesions in total and per patient (lesion-based analysis), and patients with identified primary tumour and distant metastases (patient-based analysis). The results were compared to detection rates of commonly used tracers such as 18F-FDOPA, 111In-octreotide, 99mTc-HYNIC-TOC, and 18F-FDG in literature. The local tracer uptake was measured with SUVmax, and a pancreatic cut-off value was determined. Results Histology revealed low-grade pNET (G1) in 16 patients, intermediate grade (G2) in 12, high-grade (G3) in 1, and one patient had confirming histology of a pNET but without indication of the tumour grading. Twenty patients had pathological 68Ga-DOTA-NOC metabolic lesions; of these, in 12 a primary lesion in the pancreas was identified. Here in 7/12 patients (58%), the cauda pancreatis was most commonly affected. The other 10 patients were without pathological findings. Based on the histopathological findings and multiple follow-ups, the patient-based sensitivity, specificity, and diagnostic accuracy for 68Ga-DOTA-NOC PET/CT were each 100%. The lesion-based sensitivity, specificity, and diagnostic accuracy for 15 pancreatic lesions and 253 distant metastases were 100%, respectively. Thus, according to literature the sensitivity of SRS (somatostatin receptor scintigraphy) with 111In-octreotide or 99mTc-HYNIC-TOC as well as 18F-FDOPA and 18F-FDG PET/CT for pNETs was with less than 50-60%, 87%, 80%, and 60%, respectively significantly lower than that of 68Ga-DOTA-NOC PET/CT calculated in the present study. The calculated cut-off value of SUVmax is 23.27 in this study with a sensitivity of 100% and specificity of 60%. Furthermore, there were significant differences of the median SUVmax with regard to sex, functioning, Ki-67 index, and 2010 WHO classification within the pathological 68Ga-DOTA-NOC results. Conclusion The SSR-2,3,5-specific tracer 68Ga-DOTA-NOC detects significantly more lesions, and with higher accuracy, in well-differentiated pNETs with positive somatostatin receptor (SSR) expression than any other tracer used for the detection and staging of neuroendocrine tumours of the pancreas. 68Ga-DOTA-NOC should be considered as the gold standard for functional nuclear imaging of pNETs. 18F-FDOPA is more suitable for well-differentiated tumours with low or variable SSR expression. 18F-FDG appears to be the best option for high-grade pNET.