PurposePeptide receptor radionuclide therapy (PRRT) using radiolabelled somatostatin analogues is a treatment option for patients with disseminated neuroendocrine tumours (NET). A combination treatment using the high-energy 90Y beta emitter for larger lesions and the lower energy 177Lu for smaller lesions has been postulated in the literature.The aim of the study was to evaluate combined 90Y/177Lu-DOTATATE therapy in comparison to 90Y-DOTATATE alone.MethodsFifty patients with disseminated NET were included in the study prospectively and divided into two groups: group A (n = 25) was treated with 90Y-DOTATATE, whereas group B (n = 25) received the 1:1 90Y/177Lu-DOTATATE. The administered activity was based on 3.7 GBq/m2 body surface area in three to five cycles, with amino acid infusion for nephroprotection.ResultsThe median overall survival time in group A was 26.2 months while in group B median survival was not reached. Overall survival was significantly higher in group B (p = 0.027). Median event-free survival time in group A was 21.4 months and in group B 29.4 months (p > 0.1). At the 12-month follow-up, comparison of group A vs group B showed stable disease (SD) in 13 vs 16 patients, disease regression (RD) in 5 vs 3 patients and disease progression (PD) in 3 vs 4 patients; 4 and 2 patients died, respectively. The 24-month follow-up results were SD in nine vs ten patients, RD in one patient vs none and PD in four patients in both groups; three and four patients died, respectively. Side effects were rare and mild.ConclusionThe results indicate that therapy with tandem radioisotopes (90Y/177Lu-DOTATATE) provides longer overall survival than with a single radioisotope (90Y-DOTATATE) and the safety of both methods is comparable.

An increased interest in gastro-entero-pancreatic neuroendocrine neoplasms (GEP NENs) has recently been observed. These are rare neoplasms and their detection in recent years has improved. Over 50% of GEP NENs are carcinoids, and they are usually found incidentally during surgery in the small intestine and appendix and at diagnosis in distant metastases, mainly to the liver. There is a need for co-operation between specialists in various disciplines of medicine in order to work out the diagnostic and therapeutic guidelines. In this publication, we present general recommendations of the Polish Network of Neuroendocrine Tumours for the management of patients with GEP NENs, developed at the Consensus Conference which took place in Kamień Śląski in April 2013. Members of the guidelines working groups were assigned sections of the 2008 guidance to update. In the subsequent parts of this publication, we present the rules of diagnostic and therapeutic management of: -neuroendocrine neoplasms of the stomach and duodenum (including gastrinoma); -pancreatic neuroendocrine neoplasms; -neuroendocrine neoplasms of the small intestine and the appendix; -colorectal neuroendocrine neoplasms. The proposed recommendations by Polish and foreign experts representing different fields of medicine (endocrinology, gastroenterology, surgery, oncology, nuclear medicine and pathology) will be helpful in the diagnosis and treatment of GEP NENs patients.

PurposeThe objective of this article is to present a new method for the diagnosis of insulinoma with the use of [Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4.MethodsStudies were performed in 11 patients with negative results of all available non-isotopic diagnostic methods (8 with symptoms of insulinoma, 2 with malignant insulinoma and 1 with nesidioblastosis). In all patients glucagon-like peptide-1 (GLP-1) receptor imaging (whole-body and single photon emission computed tomography/CT examinations) after the injection of 740 MBq of the tracer was performed.ResultsBoth sensitivity and specificity of GLP-1 receptor imaging were assessed to be 100 % in patients with benign insulinoma. In all eight cases with suspicion of insulinoma a focal uptake in the pancreas was found. In six patients surgical excision of the tumour was performed (type G1 tumours were confirmed histopathologically). In one patient surgical treatment is planned. One patient was disqualified from surgery. In one case with malignant insulinoma pathological accumulation of the tracer was found only in the region of local recurrence. The GLP-1 study was negative in the other malignant insulinoma patient. In one case with suspicion of nesidioblastosis, a focal accumulation of the tracer was observed and histopathology revealed coexistence of insulinoma and nesidioblastosis.Conclusion[Lys40(Ahx-HYNIC-99mTc/EDDA)NH2]-exendin-4 seems to be a promising diagnostic tool in the localization of small insulinoma tumours, but requires verification in a larger series of patients.

PurposeNeuroendocrine tumours (NET) are a heterogeneous group of neoplasms of diffuse neuroendocrine cells. Surgery is the main aim in the treatment of NETs, which becomes impossible in the case of large tumours or infiltration into other tissues and/or important blood vessels. Neoadjuvant therapy might be helpful in decreasing NET size also, leading us to the point where a tumour, previously considered inoperable, becomes operable. The aim of the study was to assess the usage of peptide receptor radionuclide therapy (PRRT) as a neoadjuvant treatment, enabling surgical intervention in primary inoperable NET.MethodsAmong 47 patients treated with PRRT, 6 patients were chosen with large, inoperable tumours, for whom enabling of complete surgical excision of the lesions might offer the prospect for a cure. Response to the therapy was assessed according to Response Evaluation Criteria In Solid Tumors (RECIST).ResultsThe mean tumour size decreased from 6.9 (min. 3.1 cm, max. 9.6 cm) before therapy to 5.4 cm (min. 3.1 cm, max. 9.5 cm) after the treatment. According to RECIST, stabilization of the disease was observed in four and partial responses in two patients. In two patients, reduction of the tumour size enabled surgical intervention.Conclusion(1) PRRT might be considered a neoadjuvant therapy in primary inoperable NETs. (2) According to RECIST, stabilization of the disease was observed in the majority of patients. (3) We suggest that not only tumour diameter changes, but also tumour volume and contrast enhancement changes in computed tomography should be taken into consideration in assessment of the response to the therapy. (4) Somatostatin receptor scintigraphy is an important tool for qualification of the radioisotope therapy and also for the assessment of the response to PRRT.

99mTc-EDDA/HYNIC-octreotate, with high imaging quality, is an excellent alternative to 111In-Octreoscan for staging of carcinoids, and it seems to be the method of choice for detection of the primary focus in patients with metastases from an unknown primary tumour.