scholarly journals Somatostatin receptor-based imaging and therapy of gastroenteropancreatic neuroendocrine tumors

2010 ◽  
Vol 17 (1) ◽  
pp. R53-R73 ◽  
Author(s):  
Dik J Kwekkeboom ◽  
Boen L Kam ◽  
Martijn van Essen ◽  
Jaap J M Teunissen ◽  
Casper H J van Eijck ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Pet Imaging ◽  
Tumor Regression ◽  
Somatostatin Receptor ◽  
Somatostatin Analogs ◽  
Receptor Subtype ◽  
Receptor Imaging ◽  
Gastroenteropancreatic Neuroendocrine Tumors ◽  
Pet Tracer ◽  
First Choice

Somatostatin receptor imaging (SRI) with [111In-DTPA0]octreotide has proven its role in the diagnosis and staging of gastroenteropancreatic neuroendocrine tumors (GEPNETs). Newer radiolabeled somatostatin analogs which can be used in positron emission tomography (PET) imaging, and which have a higher affinity for the somatostatin receptor, especially receptor subtype-2, have been developed. It would be desirable, however, if one radiolabeled analog became the new standard for PET imaging, because the current application of a multitude of analogs implies a fragmented knowledge on the interpretation of the images that are obtained in clinical practice. In our view, the most likely candidates for such a universal PET tracer for SRI are [68Ga-DOTA0,Tyr3]octreotate or [68Ga-DOTA0,Tyr3]octreotide. Treatment with radiolabeled somatostatin analogs is a promising new tool in the management of patients with inoperable or metastasized neuroendocrine tumors. Symptomatic improvement may occur with all 111In-, 90Y-, or 177Lu-labeled somatostatin analogs that have been used for peptide receptor radionuclide therapy (PRRT). The results that were obtained with [90Y-DOTA0,Tyr3]octreotide and [177Lu-DOTA0,Tyr3]octreotate are very encouraging in terms of tumor regression. Also, if kidney protective agents are used, the side effects of this therapy are few and mild, and the median duration of the therapy response for these radiopharmaceuticals is 30 and 40 months respectively. The patients' self-assessed quality of life increases significantly after treatment with [177Lu-DOTA0,Tyr3]octreotate. Lastly, compared to historical controls, there is a benefit in overall survival of several years from the time of diagnosis in patients treated with [177Lu-DOTA0,Tyr3]octreotate. These data compare favorably with the limited number of alternative treatment approaches. If more widespread use of PRRT can be guaranteed, such therapy may well become the therapy of first choice in patients with metastasized or inoperable GEPNETs.

scholarly journals Somatostatin Receptors and Analogs in Pheochromocytoma and Paraganglioma: Old Players in a New Precision Medicine World

2021 ◽  
Vol 12 ◽  
Author(s):  
Mayank Patel ◽  
Isabel Tena ◽  
Abhishek Jha ◽  
David Taieb ◽  
Karel Pacak
Keyword(s):  
Neuroendocrine Tumors ◽  
Somatostatin Receptor ◽  
Hormone Secretion ◽  
Somatostatin Receptors ◽  
Somatostatin Analogs ◽  
Rare Condition ◽  
Receptor Imaging ◽  
Gastroenteropancreatic Neuroendocrine Tumors ◽  
Well Differentiated ◽  
Succinate Dehydrogenase Subunit B

Neuroendocrine tumors overexpress somatostatin receptors, which serve as important and unique therapeutic targets for well-differentiated advanced disease. This overexpression is a well-established finding in gastroenteropancreatic neuroendocrine tumors which has guided new medical therapies in the administration of somatostatin analogs, both “cold”, particularly octreotide and lanreotide, and “hot” analogs, chelated to radiolabeled isotopes. The binding of these analogs to somatostatin receptors effectively suppresses excess hormone secretion and tumor cell proliferation, leading to stabilization, and in some cases, tumor shrinkage. Radioisotope-labeled somatostatin analogs are utilized for both tumor localization and peptide radionuclide therapy, with 68Ga-DOTATATE and 177Lu-DOTATATE respectively. Benign and malignant pheochromocytomas and paragangliomas also overexpress somatostatin receptors, irrespective of embryological origin. The pattern of somatostatin receptor overexpression is more prominent in succinate dehydrogenase subunit B gene mutation, which is more aggressive than other subgroups of this disease. While the Food and Drug Administration has approved the use of 68Ga-DOTATATE as a radiopharmaceutical for somatostatin receptor imaging, the use of its radiotherapeutic counterpart still needs approval beyond gastroenteropancreatic neuroendocrine tumors. Thus, patients with pheochromocytoma and paraganglioma, especially those with inoperable or metastatic diseases, depend on the clinical trials of somatostatin analogs. The review summarizes the advances in the utilization of somatostatin receptor for diagnostic and therapeutic approaches in the neuroendocrine tumor subset of pheochromocytoma and paraganglioma; we hope to provide a positive perspective in using these receptors as targets for treatment in this rare condition.

scholarly journals Localization of Neuroendrocrine Tumors Using Somatostatin Receptor Imaging with Indium-111-Pentetreotide (OctreoScan)

1997 ◽  
Vol 4 (1) ◽  
pp. 1-3 ◽  
Author(s):  
E. Christopher Ellison ◽  
William J. Schirmer ◽  
John O. Olsen ◽  
Rodney V. Pozderac ◽  
George Hinkle ◽  
...  
Keyword(s):  
Neuroendocrine Tumors ◽  
Imaging Techniques ◽  
Somatostatin Receptor ◽  
Somatostatin Receptors ◽  
Receptor Imaging ◽  
Gastroenteropancreatic Neuroendocrine Tumors ◽  
Primary Tumors ◽  
Duodenal Tumor ◽  
Computed Tomography Scanning ◽  
Indium 111

Background Many imaging methods have been used to detect neuroendocrine tumors of the gastrointestinal system. There is no gold standard for identifying the location of primary tumors and their potential metastases, and most conventional imaging techniques cannot detect tumors less than 1.0 cm in size. Methods The authors have investigated the use of 111In-pentetreotide as an imaging agent for abdominal neuroendocrine tumors. Results The agent is cleared rapidly by the kidneys and is primarily excreted intact with a biologic half-life of six hours. The largest radiation burden is to the spleen and kidneys. A nine-center study conducted in Europe involved 365 patients with gastroenteropancreatic neuroendocrine tumors that were also imaged by other methods. The results of 111In-pentetreotide were in agreement with those obtained by other methods for 79% of tumor locations. An additional 110 tumor localizations were detected that were not seen with conventional methods. The smallest gastrinoma imaged by 111In-pentetreotide was a 4-mm duodenal tumor. Conclusions Scintigraphy with 111In-pentetreotide is effective in visualizing various somatostatin receptors characteristic of neuroendocrine tumors of the gastrointestinal tract. Insulinomas, however, are not well imaged. Concurrent computed tomography scanning is advised to minimize the risk of missing liver metastases.

scholarly journals Assessment of γ-H2AX and 53BP1 Foci in Peripheral Blood Lymphocytes to Predict Subclinical Hematotoxicity and Response in Somatostatin Receptor-Targeted Radionuclide Therapy for Advanced Gastroenteropancreatic Neuroendocrine Tumors

Cancers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1516
Author(s):  
Thorsten Derlin ◽  
Natalia Bogdanova ◽  
Fiona Ohlendorf ◽  
Dhanya Ramachandran ◽  
Rudolf A. Werner ◽  
...  
Keyword(s):  
Treatment Response ◽  
Neuroendocrine Tumors ◽  
Peripheral Blood ◽  
Somatostatin Receptor ◽  
Therapy Response ◽  
Strand Break ◽  
Peripheral Blood Lymphocytes ◽  
Radioligand Therapy ◽  
Gastroenteropancreatic Neuroendocrine Tumors ◽  
Blood Lymphocytes

Background: We aimed to characterize γ-H2AX and 53BP1 foci formation in patients receiving somatostatin receptor-targeted radioligand therapy, and explored its role for predicting treatment-related hematotoxicity, and treatment response. Methods: A prospective analysis of double-strand break (DSB) markers was performed in 21 patients with advanced gastroenteropancreatic neuroendocrine tumors. γ-H2AX and 53BP1 foci formation were evaluated in peripheral blood lymphocytes (PBLs) at baseline, +1 h and +24 h after administration of 7.4 GBq (177Lu)Lu-DOTA-TATE. Hematotoxicity was evaluated using standard hematology. Therapy response was assessed using (68Ga)Ga-DOTA-TATE PET/CT before enrollment and after 2 cycles of PRRT according to the volumetric modification of RECIST 1.1. Results: DSB marker kinetics were heterogeneous among patients. Subclinical hematotoxicity was associated with γ-H2AX and 53BP1 foci formation (e.g., change in platelet count vs change in γ-H2AX+ cells between baseline and +1 h (r = −0.6080; p = 0.0045). Patients showing early development of new metastases had less γ-H2AX (p = 0.0125) and less 53BP1 foci per cell at +1 h (p = 0.0289), and demonstrated a distinct kinetic pattern with an absence of DSB marker decrease at +24 h (γ-H2AX: p = 0.0025; 53BP1: p = 0.0008). Conclusions: Assessment of γ-H2AX and 53BP1 foci formation in PBLs of patients receiving radioligand therapy may hold promise for predicting subclinical hematotoxicity and early treatment response.

Optimizing Somatostatin Receptor Imaging in Patients With Neuroendocrine Tumors

2017 ◽  
Vol 42 (12) ◽  
pp. 905-911 ◽  
Author(s):  
Jolanta Kunikowska ◽  
Valerie Lewington ◽  
Leszek Krolicki
Keyword(s):  
Neuroendocrine Tumors ◽  
Somatostatin Receptor ◽  
Receptor Imaging ◽  
Somatostatin Receptor Imaging

scholarly journals Ghrelin Receptor (GHS-R1a) and Its Constitutive Activity in Somatotroph Adenomas: A New Co-targeting Therapy Using GHS-R1a Inverse Agonists and Somatostatin Analogs

2014 ◽  
Vol 99 (12) ◽  
pp. E2463-E2471 ◽  
Author(s):  
Yves Mear ◽  
Marie-Pierre Blanchard ◽  
Céline Defilles ◽  
Thierry Brue ◽  
Dominique Figarella-Branger ◽  
...  
Keyword(s):  
Somatostatin Receptor ◽  
Somatostatin Analogs ◽  
Inverse Agonist ◽  
Receptor Subtype ◽  
Dependent Manner ◽  
Constitutive Activity ◽  
Targeting Therapy ◽  
Ghrelin Receptor ◽  
Gh Secretion

Context: The ghrelin receptor GHS-R1a is highly expressed in human somatotroph adenomas and exhibits unusually high basal signaling activity. In humans, the suppression of this constitutive activity by mutation induces a short stature. Objective: Using a GHS-R1a inverse agonist, modified substance P (MSP), we explored the role of GHS-R1a constitutive activity in GH hypersecretion from somatotroph adenomas and as a putative therapeutic target. Design: The effects of MSP were assessed on GH secretion from 19 human somatotroph tumors in vitro. Moreover, these effects were compared with those of octreotide (somatostatin receptor subtype 2 [sst2] agonist) and with the combination of both drugs. Expression and localization of GHS-R1a and sst2 were studied. Results: For all tumors, MSP inhibited GH secretion in a dose-dependent manner from 13 to 64%. Moreover, MSP enhanced octreotide-induced GH inhibition. For five tumors, the effects of combined MSP plus octreotide treatment were significantly higher than the sum of effects of each drug alone. MSP increased the membrane localization of GHS-R1a and of microdomains colocalizing sst2-GHS-R1a, highlighting the cooperation between the two drugs. Conclusions: The GHS-R1a inverse agonist could open new therapeutic options for acromegalic patients, particularly patients partially sensitive to octreotide whose GH secretion is not completely controlled by the sst2 agonist.

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