The modern pre- and intraoperative diagnostic algorithm of pancreatic NET with the use of 99mTc-EDDA/HYNIC-octreate scintigraphy the impact of SRS on patients management
Alicja Hubalewska-Dydejczyk1, Katarzyna Fröss-Baron1, Renata Mikolajczak2, Bogdan Huszno1, Piotr Szybinski3, Jan Kulig3, Aleksandra Januszewska1, Anna Sowa-Staszczak1 & Dorota Pach1
Pancreatic NETs often cause difficulties in imaging diagnostics and optimal diagnostic algorithm is searched for. According to the latest reports MDCT sensitivity amounts 60-90%, MR: 80-90%, SRS: 62-100%, EUS: 70-90%.
Aim: Assessment of the usefulness of 99 mTc-EDDA/HYNIC-octreotae scintigraphy in detection of primary and metastatic tumours of pancreatic NET in comparison to CT, EUS and IOUS and evaluation of the impact of scintigraphic results on clinical management of these patients.
Materials and methods: 27 patients (aged 52.0±17.3 y) with suspected or histopathologically confirmed pancreatic NET were qualified for the study. Imaging diagnostics was performed in order to detect the primary lesions, local recurrences an metastases. 99 mTc-EDDA/HYNIC-octreotate SRS, CT, EUS and IOUS were performed. The patients with positive SRS were qualified for RGS.
Results: On the basis of the imaging methods results and histopathologic verification: insulinoma- 8, glucagonoma-6, gastrinoma-5, somatostatinoma-2, NET with ACTH ectopy-2, non-functioning NET- in 4 pts were finally diagnosed. Primary lesions (16) and local recurrences (4) were revealed in 20pts, and metastases in 8pts. Sensitivity of SRS and CT was 85% vs 65% respectively. SRS visualized metastatic lesion in 100%, while CT in 87.5% of pts. IOUS revealed the primary tumours in all cases of insulinoma and gastrinoma (9/9). SRS and EUS detected 5/7 insulinoma and 2/2 gastrinoma (CT: 3 insulinomas, 1gastrinoma). SRS changed the diagnostic approach in 13 pts: 8 were qualified for 90Y-DOTA-TATE therapy and 2pts with negative SRS were referred for chemiotherapy. 2 insulinomas and glucagonoma liver metastases were visualised only in SRS and detected with hand-held gamma-probe intra-operatively.
Conclusions: 99 mTc-EDDA/HYNIC-octreotate SRS is a sensitive method of pancreatic NET detection. It is particularly useful in visualisation of the small tumours of the pancreatic tail and small liver metastases. It has essential impact on patients treatment as it enables tumoursresection with RGS and selects patients for PRRT with 90Y-DOTA-TATE.