Factors influencing radioguided surgery of neuroendocrine tumours using 99mTc-ethylenediamine N,N'-diacetic acid/6-Hydrazinopyridine-3-carboxylic acid-D-Phe1-Tyr3-octreotide.
OBJECTIVE
To determine factors influencing radioguided surgery of neuroendocrine tumours using Tc-ethylenediamine N,N'-diacetic acid/6-Hydrazinopyridine-3-carboxylic acid-D-Phe-Tyr-octreotide and gamma-probe.


METHODS
Patients with 17 neuroendocrine tumours were operated on. Three to 6 h before surgery, 550-650 MBq of Tc-labelled octreotide were injected into the patients. Scintigraphy was performed immediately before surgery to confirm uptake of the radiopharmaceutical by the tumour. The uptake was graded on a scale from 0 to 4. Local measurements of radioactivity were performed during surgery using a gamma-probe and small lead shields.


RESULTS
Intraoperatively 12 tumours in 11 patients were successfully localized using a gamma-probe: three tumours with uptake grade 4, seven with grade 3 and two with grade 2. Seven tumours were localized in the region of the pancreas, two next to the aortic bifurcation, one in the mesentery and two in the ileocecal region. Tumours were not found in five patients. They were all positive on scintigraphy with tracer uptake grade 4 in one patient, grade 3 in one, and grade 2 in three patients. Localization was confirmed by endoscopic ultrasound, computed tomography and/or MRI. All five tumours were located in the pancreatic area. In four of these patients, tumours were seen in the same localization as preoperatively on follow-up scintigraphy 6-12 months later.


CONCLUSIONS
Factors influencing the success of surgery were high octreotide uptake (grades 3 and 4) and localization of the tumour away from kidneys and spleen. Positive localization on endoscopic ultrasound, computed tomography or MRI, size of tumour, pathohistology and reoperations did not influence surgical success.
Hodolic
Marina
M
Departments of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia. marina.hodolic@kclj.si
Fettich
Jure
J
Repse
Stane
S
Peitl
Petra
P
Lezaic
Luka
L
Hojker
Sergej
S
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000000981:diagnostic imaging* / Q000601:surgery*; D015609:Organotechnetium Compounds; D011379:Prognosis; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*; D016896:Treatment Outcome
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C487389:technetium 99m EDDA-HYNIC-Tyr(3)-octreotide