Browsing by Author "Todorović-Tirnanić, Mila (12772684600)"

The new positron emission tomography (PET/CT) methods for neuroendocrine tumors detection are presented and compared with classic, conventional methods. Conventional methods use a gamma scintillation camera for patients with neuroendocrine tumor imaging, after intravenous injection of one of the following radiopharmaceuticals: 1) somatostatin analogues labeled with indium-111 (111In-pentetreotide) or technetium-99m (99mTc-EDDA/HYNIC-TOC); 2) noradrenaline analogue labeled with iodine-131 or -123 (131I/123I-MIBG); or 3)99mTc(V)-DMSA. Contemporary methods use PET/CT equipment for patients with neuroendocrine tumor imaging, after intravenous injection of pharmaceuticals labeled with positron emitters [fluorine-18 (18F), galium-68 (68Ga), or carbon-11 (11C)]: 1) glucose analogue (18FDG); 2) somatostatin analogue (68Ga-DOTATOC/68Ga-DOTATATE/68Ga-DOTANOC); 3) aminoacid precursors of bioamines: [a) dopamine precursor18F-DOPA (6-18F-dihydroxyphenylalanine), b) serotonin precursor11C-5HTP (11C-5-hydroxytryptophan)]; or 4) dopamine analogue 18F-DA (6-18F-fluorodopamine). Conventional and contemporary (PET/ CT) somatostatin receptor detection showed identical high specificity (92%), but conventional had very low sensitivity (52%) compared to PET/CT (97%). It means that almost every second neuroendocrine tumor detected by contemporary method cannot be discovered using conventional (classic) method. In metastatic pheochromocytoma detection contemporary (PET/ CT) methods (18F-DOPA and18F-DA) have higher sensitivity than conventional (131I/123I-MIBG). In medullary thyroid carcinoma diagnostics contemporary method (18F-DOPA) is more sensitive than conventional 99mTc(V)-DMSA method, and is similar to 18FDG, computed tomography and magnetic resonance. In carcinoid detection contemporary method (18F-DOPA) shows similar results with contemporary somatostatin receptor detection, while for gastroenteropancreatic neuroendocrine tumors it is worse. To conclude, contemporary (PET/CT) methods for somatostatin receptor detection (68Ga-DOTATOC/-NOC/-TATE) in neuroendocrine tumors are much more sensitive (almost twice) and more accurate than conventional. Therefore the classical methods should be urgently replaced by contemporary methods.

[No abstract available]

Aim: The aim of this chapter is to present the results of the first intraoperative somatostatin receptor detection after peptide receptor radionuclide therapy (PRRNT) with 90Y- and 177Lu-DOTATOC using a handheld gamma probe and comparison with the findings of preoperative 68Ga-DOTATOC PET/CT in a patient with a metastatic neuroendocrine tumor (NET) of the ileum. Materials and Methods: A 56-year-old female patient, treated twice by PRRNT, was admitted for the third cycle and subsequent surgery. Before operation, the following studies were performed for restaging after the second cycle of PRRNT: 99mTc-MAG3 + TER, 99mTc-DTPA + GFR, abdominal ultrasonography, MRI of the abdomen, 68Ga-DOTATOC PET/CT as well as 18F-fluoride PET/CT. Serum tumor markers were measured before and after PRRNT. Tandem PRRNT was performed using 3000 MBq 90Y-DOTATOC and 6000 MBq 177Lu-DOTATOC. Whole-body scintigrams were obtained at 23 and 43 h. Five days after PRRNT, the patient was operated using a handheld gamma probe. Immunohistochemistry and histopathology of the resected tissue were performed. Results: Tandem PRRNT was very well tolerated by the patient. Before PRRNT, 68Ga-DOTATOC PET/CT revealed the primary tumor in the ileocoecal region as well as bilobular liver metastases and a right iliac bone lesion (osteoblastic on 18F-fluoride PET/CT). Compared with the previous findings, there was good therapy response (partial remission of the tumor lesions). No nephrotoxicity was observed. Serum chromogranin A (836 μg/l, n < 100) and serotonin (852 μg/l, n < 200) were strongly elevated. Posttherapy scans showed intense uptake in metastases and the primary tumor. Intraoperative gamma probe detectedin addition to the known lesionsbilateral ovarian metastases not visualized by 68Ga- DOTATOC PET/CT. Bilateral adnexectomy, right hemicolectomy, excision of hepatic metastases in S3, and partial resection of peritoneum were performed. Histopathology confirmed metastases in both ovaries. Conclusions: Gamma probe-guided surgery after 177Lu PRRNT is feasible and appears to be more sensitive than 68Ga-DOTATOC PET/CT. This technique might aid the surgeon in achieving more complete tumor resection through intraoperative detection of very small lesions (<5 mm) directly after PRRNT. © 2013 Springer-Verlag Berlin Heidelberg.

Aim: The aim of this chapter is to present the results of the first intraoperative somatostatin receptor detection after peptide receptor radionuclide therapy (PRRNT) with 90Y- and 177Lu-DOTATOC using a handheld gamma probe and comparison with the findings of preoperative 68Ga-DOTATOC PET/CT in a patient with a metastatic neuroendocrine tumor (NET) of the ileum. Materials and Methods: A 56-year-old female patient, treated twice by PRRNT, was admitted for the third cycle and subsequent surgery. Before operation, the following studies were performed for restaging after the second cycle of PRRNT: 99mTc-MAG3 + TER, 99mTc-DTPA + GFR, abdominal ultrasonography, MRI of the abdomen, 68Ga-DOTATOC PET/CT as well as 18F-fluoride PET/CT. Serum tumor markers were measured before and after PRRNT. Tandem PRRNT was performed using 3000 MBq 90Y-DOTATOC and 6000 MBq 177Lu-DOTATOC. Whole-body scintigrams were obtained at 23 and 43 h. Five days after PRRNT, the patient was operated using a handheld gamma probe. Immunohistochemistry and histopathology of the resected tissue were performed. Results: Tandem PRRNT was very well tolerated by the patient. Before PRRNT, 68Ga-DOTATOC PET/CT revealed the primary tumor in the ileocoecal region as well as bilobular liver metastases and a right iliac bone lesion (osteoblastic on 18F-fluoride PET/CT). Compared with the previous findings, there was good therapy response (partial remission of the tumor lesions). No nephrotoxicity was observed. Serum chromogranin A (836 μg/l, n < 100) and serotonin (852 μg/l, n < 200) were strongly elevated. Posttherapy scans showed intense uptake in metastases and the primary tumor. Intraoperative gamma probe detectedin addition to the known lesionsbilateral ovarian metastases not visualized by 68Ga- DOTATOC PET/CT. Bilateral adnexectomy, right hemicolectomy, excision of hepatic metastases in S3, and partial resection of peritoneum were performed. Histopathology confirmed metastases in both ovaries. Conclusions: Gamma probe-guided surgery after 177Lu PRRNT is feasible and appears to be more sensitive than 68Ga-DOTATOC PET/CT. This technique might aid the surgeon in achieving more complete tumor resection through intraoperative detection of very small lesions (<5 mm) directly after PRRNT. © 2013 Springer-Verlag Berlin Heidelberg.