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Richter S, Steenblock C, Fischer A, Lemm S, Ziegler CG, Bechmann N, Nölting S, Pietzsch J, Ullrich M. Improving susceptibility of neuroendocrine tumors to radionuclide therapies: personalized approaches towards complementary treatments. Theranostics 2024; 14:17-32. [PMID: 38164150 PMCID: PMC10750207 DOI: 10.7150/thno.87345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/30/2023] [Indexed: 01/03/2024] Open
Abstract
Radionuclide therapies are an important tool for the management of patients with neuroendocrine neoplasms (NENs). Especially [131I]MIBG and [177Lu]Lu-DOTA-TATE are routinely used for the treatment of a subset of NENs, including pheochromocytomas, paragangliomas and gastroenteropancreatic tumors. Some patients suffering from other forms of NENs, such as medullary thyroid carcinoma or neuroblastoma, were shown to respond to radionuclide therapy; however, no general recommendations exist. Although [131I]MIBG and [177Lu]Lu-DOTA-TATE can delay disease progression and improve quality of life, complete remissions are achieved rarely. Hence, better individually tailored combination regimes are required. This review summarizes currently applied radionuclide therapies in the context of NENs and informs about recent advances in the development of theranostic agents that might enable targeting subgroups of NENs that previously did not respond to [131I]MIBG or [177Lu]Lu-DOTA-TATE. Moreover, molecular pathways involved in NEN tumorigenesis and progression that mediate features of radioresistance and are particularly related to the stemness of cancer cells are discussed. Pharmacological inhibition of such pathways might result in radiosensitization or general complementary antitumor effects in patients with certain genetic, transcriptomic, or metabolic characteristics. Finally, we provide an overview of approved targeted agents that might be beneficial in combination with radionuclide therapies in the context of a personalized molecular profiling approach.
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Affiliation(s)
- Susan Richter
- Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Charlotte Steenblock
- Department of Internal Medicine III, University Clinic Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Alessa Fischer
- Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Zurich (USZ), and University of Zurich (UZH), Zurich, Switzerland
| | - Sandy Lemm
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Dresden, Germany
| | - Christian G. Ziegler
- Department of Internal Medicine III, University Clinic Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- University Hospital Würzburg, Division of Endocrinology and Diabetes, Würzburg, Germany
| | - Nicole Bechmann
- Institute for Clinical Chemistry and Laboratory Medicine, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Svenja Nölting
- Department of Endocrinology, Diabetology and Clinical Nutrition, University Hospital Zurich (USZ), and University of Zurich (UZH), Zurich, Switzerland
- Department of Medicine IV, University Hospital, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Jens Pietzsch
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
- Faculty of Chemistry and Food Chemistry, School of Science, Technische Universität Dresden, Dresden, Germany
| | - Martin Ullrich
- Department of Radiopharmaceutical and Chemical Biology, Institute of Radiopharmaceutical Cancer Research, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
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Klomp MJ, van den Brink L, van Koetsveld PM, de Ridder CMA, Stuurman DC, Löwik CWGM, Hofland LJ, Dalm SU. Applying HDACis to increase SSTR2 expression and radiolabeled DOTA-TATE uptake: from cells to mice. Life Sci 2023; 334:122173. [PMID: 37907154 DOI: 10.1016/j.lfs.2023.122173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/01/2023] [Accepted: 10/10/2023] [Indexed: 11/02/2023]
Abstract
AIMS The aim of our study was to determine the effect of histone deacetylase (HDAC) inhibitors (HDACis) on somatostatin type-2 receptor (SSTR2) expression and [111In]In-/[177Lu]Lu-DOTA-TATE uptake in vitro and in vivo. MATERIALS AND METHODS The human cell lines NCI-H69 (small-cell lung carcinoma) and BON-1 (pancreatic neuroendocrine tumor) were treated with HDACis (i.e. entinostat, mocetinostat (MOC), LMK-235, CI-994 or panobinostat (PAN)), and SSTR2 mRNA expression levels and [111In]In-DOTA-TATE uptake were measured. Furthermore, vehicle- and HDACi-treated NCI-H69 and BON-1 tumor-bearing mice were injected with radiolabeled DOTA-TATE followed by biodistribution studies. Additionally, SSTR2 and HDAC mRNA expression of xenografts, and of NCI-H69, BON-1, NCI-H727 (human pulmonary carcinoid) and GOT1 (human midgut neuroendocrine tumor) cells were determined. KEY FINDINGS HDACi treatment resulted in the desired effects in vitro. However, no significant increase in tumoral DOTA-TATE uptake was observed after HDACi treatment in NCI-H69 tumor-bearing animals, whereas tumoral SSTR2 mRNA and/or protein expression levels were significantly upregulated after treatment with MOC, CI-994 and PAN, i.e. a maximum of 2.1- and 1.3-fold, respectively. Analysis of PAN-treated BON-1 xenografts solely demonstrated increased SSTR2 mRNA expression levels. Comparison of HDACs and SSTR2 expression in BON-1 and NCI-H69 xenografts showed a significantly higher expression of 6/11 HDACs in BON-1 xenografts. Of these HDACs, a significant inverse correlation was found between HDAC3 and SSTR2 expression (Pearson r = -0.92) in the studied cell lines. SIGNIFICANCE To conclude, tumoral uptake levels of radiolabeled DOTA-TATE were not enhanced after HDACi treatment in vivo, but, depending on the applied inhibitor, increased SSTR2 expression levels were observed.
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Affiliation(s)
- Maria J Klomp
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands; Department of Internal Medicine, Division of Endocrinology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Lilian van den Brink
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Peter M van Koetsveld
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Corrina M A de Ridder
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands; Department of Experimental Urology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Debra C Stuurman
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands; Department of Experimental Urology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Clemens W G M Löwik
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Leo J Hofland
- Department of Internal Medicine, Division of Endocrinology, Erasmus MC, 3015 GD Rotterdam, The Netherlands
| | - Simone U Dalm
- Department of Radiology and Nuclear Medicine, Erasmus MC, 3015 GD Rotterdam, The Netherlands.
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Klomp MJ, Refardt J, van Koetsveld PM, Campana C, Dalm SU, Dogan F, van Velthuysen MLF, Feelders RA, de Herder WW, Hofland J, Hofland LJ. Epigenetic regulation of SST 2 expression in small intestinal neuroendocrine tumors. Front Endocrinol (Lausanne) 2023; 14:1184436. [PMID: 37223009 PMCID: PMC10200989 DOI: 10.3389/fendo.2023.1184436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 04/11/2023] [Indexed: 05/25/2023] Open
Abstract
Background Somatostatin receptor type 2 (SST2) expression is critical for the diagnosis and treatment of neuroendocrine tumors and is associated with improved patient survival. Recent data suggest that epigenetic changes such as DNA methylation and histone modifications play an important role in regulating SST2 expression and tumorigenesis of NETs. However, there are limited data on the association between epigenetic marks and SST2 expression in small intestinal neuroendocrine tumors (SI-NETs). Methods Tissue samples from 16 patients diagnosed with SI-NETs and undergoing surgical resection of the primary tumor at Erasmus MC Rotterdam were analysed for SST2 expression levels and epigenetic marks surrounding the SST2 promoter region, i.e. DNA methylation and histone modifications H3K27me3 and H3K9ac. As a control, 13 normal SI-tissue samples were included. Results The SI-NET samples had high SST2 protein and mRNA expression levels; a median (IQR) of 80% (70-95) SST2-positive cells and 8.2 times elevated SST2 mRNA expression level compared to normal SI-tissue (p=0.0042). In comparison to normal SI-tissue, DNA methylation levels and H3K27me3 levels were significantly lower at five out of the eight targeted CpG positions and at two out of the three examined locations within the SST2 gene promoter region of the SI-NET samples, respectively. No differences in the level of activating histone mark H3K9ac were observed between matched samples. While no correlation was found between histone modification marks and SST2 expression, SST2 mRNA expression levels correlated negatively with DNA methylation within the SST2 promoter region in both normal SI-tissue and SI-NETs (p=0.006 and p=0.04, respectively). Conclusion SI-NETs have lower SST2 promoter methylation levels and lower H3K27me3 methylation levels compared to normal SI-tissue. Moreover, in contrast to the absence of a correlation with SST2 protein expression levels, significant negative correlations were found between SST2 mRNA expression level and the mean level of DNA methylation within the SST2 promoter region in both normal SI-tissue and SI-NET tissue. These results indicate that DNA methylation might be involved in regulating SST2 expression. However, the role of histone modifications in SI-NETs remains elusive.
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Affiliation(s)
- Maria J. Klomp
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
- ENETS Center of Excellence, Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - Julie Refardt
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
- ENETS Center of Excellence, Department of Endocrinology, University Hospital Basel, Basel, Switzerland
| | - Peter M. van Koetsveld
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
| | - Claudia Campana
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
- Endocrinology Unit, Department of Internal Medicine and Medical Specialties, School of Medical and Pharmaceutical Sciences, University of Genova, Genova, Italy
| | - Simone U. Dalm
- ENETS Center of Excellence, Department of Radiology & Nuclear Medicine, Erasmus Medical Center, Rotterdam, Netherlands
| | - Fadime Dogan
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
| | | | - Richard A. Feelders
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
| | - Wouter W. de Herder
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
| | - Johannes Hofland
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
| | - Leo J. Hofland
- ENETS Center of Excellence, Department of Internal Medicine, Section of Endocrinology, Erasmus Medical Center (MC) Cancer Institute, Rotterdam, Netherlands
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Runge R, Naumann A, Miederer M, Kotzerke J, Brogsitter C. Up-Regulation of PSMA Expression In Vitro as Potential Application in Prostate Cancer Therapy. Pharmaceuticals (Basel) 2023; 16:ph16040538. [PMID: 37111295 PMCID: PMC10144194 DOI: 10.3390/ph16040538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/31/2023] [Accepted: 04/02/2023] [Indexed: 04/29/2023] Open
Abstract
Possibilities to improve the therapeutic efficacy of Lu-177-PSMA-617 radionuclide therapy by modulation of target expression are being investigated. Knowledge on regulatory factors that promote prostate cancer (PCa) progression may contribute to targeting prostate cancer more effectively. We aimed at the stimulation of PCa cell lines using the substances 5-aza-2'-deoxycitidine (5-aza-dC) and valproic acid (VPA) to achieve increased prostate-specific membrane antigen (PSMA) expression. PC3, PC3-PSMA, and LNCaP cells were incubated with varying concentrations of 5-aza-dC and VPA to investigate the cell-bound activity of Lu-177-PSMA-617. Stimulation effects on both the genetically modified cell line PC3-PSMA and the endogenously PSMA-expressing LNCaP cells were demonstrated by increased cellular uptake of the radioligand. For PC3-PSMA cells, the fraction of cell-bound radioactivity was enhanced by about 20-fold compared to that of the unstimulated cells. Our study reveals an increased radioligand uptake mediated by stimulation for both PC3-PSMA and LNCaP cell lines. In perspective of an enhanced PSMA expression, the present study might contribute to advanced radionuclide therapy approaches that improve the therapeutic efficacy, as well as combined treatment options.
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Affiliation(s)
- Roswitha Runge
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Anne Naumann
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Matthias Miederer
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
- National Center for Tumor Diseases (NCT), D-01307 Dresden, Germany
| | - Joerg Kotzerke
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
| | - Claudia Brogsitter
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Fetscherstrasse 74, D-01307 Dresden, Germany
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Ullrich M, Richter S, Liers J, Drukewitz S, Friedemann M, Kotzerke J, Ziegler CG, Nölting S, Kopka K, Pietzsch J. Epigenetic drugs in somatostatin type 2 receptor radionuclide theranostics and radiation transcriptomics in mouse pheochromocytoma models. Theranostics 2023; 13:278-294. [PMID: 36593963 PMCID: PMC9800739 DOI: 10.7150/thno.77918] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Accepted: 11/22/2022] [Indexed: 12/23/2022] Open
Abstract
Pheochromocytomas and paragangliomas (PCCs/PGLs) are catecholamine-producing tumors. In inoperable and metastatic cases, somatostatin type 2 receptor (SSTR2) expression allows for peptide receptor radionuclide therapy with [177Lu]Lu-DOTA-TATE. Insufficient receptor levels, however, limit treatment efficacy. This study evaluates whether the epigenetic drugs valproic acid (VPA) and 5-Aza-2'-deoxycytidine (DAC) modulate SSTR2 levels and sensitivity to [177Lu]Lu-DOTA-TATE in two mouse PCC models (MPC and MTT). Methods: Drug-effects on Sstr2/SSTR2 were investigated in terms of promoter methylation, mRNA and protein levels, and radiotracer binding. Radiotracer uptake was measured in subcutaneous allografts in mice using PET and SPECT imaging. Tumor growth and gene expression (RNAseq) were characterized after drug treatments. Results: DAC alone and in combination with VPA increased SSTR2 levels along with radiotracer uptake in vitro in MPC (high-SSTR2) and MTT cells (low-SSTR2). MTT but not MPC allografts responded to DAC and VPA combination with significantly elevated radiotracer uptake, although activity concentrations remained far below those in MPC tumors. In both models, combination of DAC, VPA and [177Lu]Lu-DOTA-TATE was associated with additive effects on tumor growth delay and specific transcriptional responses in gene sets involved in cancer and treatment resistance. Effects of epigenetic drugs were unrelated to CpG island methylation of the Sstr2 promoter. Conclusion: This study demonstrates that SSTR2 induction in mouse pheochromocytoma models has some therapeutic benefit that occurs via yet unknown mechanisms. Transcriptional changes in tumor allografts associated with epigenetic treatment and [177Lu]Lu-DOTA-TATE provide first insights into genetic responses of PCCs/PGLs, potentially useful for developing additional strategies to prevent tumor recurrence.
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Affiliation(s)
- Martin Ullrich
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Dresden, Germany.,✉ Corresponding author: Dr. Martin Ullrich, Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Bautzner Landstraße 400, 01328 Dresden, Germany. Phone: +49-351-2604046, Fax: +49-351-26012622, E-mail:
| | - Susan Richter
- University Hospital Carl Gustav Carus at the Technische Universität Dresden, Institute of Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - Josephine Liers
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Dresden, Germany.,University Hospital Carl Gustav Carus at the Technische Universität Dresden, Institute of Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - Stephan Drukewitz
- National Center for Tumor Diseases/University Cancer Center Dresden, Core Unit for Molecular Tumor Diagnostics, Dresden, Germany.,University of Leipzig Medical Center, Institute of Human Genetics, Leipzig, Germany
| | - Markus Friedemann
- University Hospital Carl Gustav Carus at the Technische Universität Dresden, Institute of Clinical Chemistry and Laboratory Medicine, Dresden, Germany
| | - Jörg Kotzerke
- University Hospital Carl Gustav Carus at the Technische Universität Dresden, Klinik und Poliklinik für Nuklearmedizin, Dresden, Germany
| | - Christian G. Ziegler
- University Hospital Carl Gustav Carus at the Technische Universität Dresden, Department of Medicine III, Dresden, Germany
| | - Svenja Nölting
- University Hospital Zurich (USZ) and University of Zurich (UZH), Department of Endocrinology, Diabetology and Clinical Nutrition, Zurich, Switzerland.,University Hospital, LMU Munich, Department of Medicine IV, Munich, Germany
| | - Klaus Kopka
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Dresden, Germany.,Technische Universität Dresden, School of Science, Faculty of Chemistry and Food Chemistry, Dresden, Germany.,German Cancer Consortium (DKTK), Partner Site Dresden, Dresden, Germany.,National Center for Tumor Diseases (NCT), Partner Site Dresden, University Cancer Center (UCC), Dresden, Germany
| | - Jens Pietzsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, Department of Radiopharmaceutical and Chemical Biology, Dresden, Germany.,Technische Universität Dresden, School of Science, Faculty of Chemistry and Food Chemistry, Dresden, Germany
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Hofland J, Brabander T, Verburg FA, Feelders RA, de Herder WW. Peptide Receptor Radionuclide Therapy. J Clin Endocrinol Metab 2022; 107:3199-3208. [PMID: 36198028 PMCID: PMC9693835 DOI: 10.1210/clinem/dgac574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 11/19/2022]
Abstract
The concept of using a targeting molecule labeled with a diagnostic radionuclide for using positron emission tomography or single photon emission computed tomography imaging with the potential to demonstrate that tumoricidal radiation can be delivered to tumoral sites by administration of the same or a similar targeting molecule labeled with a therapeutic radionuclide termed "theranostics." Peptide receptor radionuclide therapy (PRRT) with radiolabeled somatostatin analogs (SSAs) is a well-established second/third-line theranostic treatment for somatostatin receptor-positive well-differentiated (neuro-)endocrine neoplasms (NENs). PRRT with 177Lu-DOTATATE was approved by the regulatory authorities in 2017 and 2018 for selected patients with low-grade well-differentiated gastroenteropancreatic (GEP) NENs. It improves progression-free survival as well as quality of life of GEP NEN patients. Favorable symptomatic and biochemical responses using PRRT with 177Lu-DOTATATE have also been reported in patients with functioning metastatic GEP NENs like metastatic insulinomas, Verner Morrison syndromes (VIPomas), glucagonomas, and gastrinomas and patients with carcinoid syndrome. This therapy might also become a valuable therapeutic option for inoperable low-grade bronchopulmonary NENs, inoperable or progressive pheochromocytomas and paragangliomas, and medullary thyroid carcinomas. First-line PRRT with 177Lu-DOTATATE and combinations of this therapy with cytotoxic drugs are currently under investigation. New radiolabeled somatostatin receptor ligands include SSAs coupled with alpha radiation emitting radionuclides and somatostatin receptor antagonists coupled with radionuclides.
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Affiliation(s)
- Johannes Hofland
- Department of Internal Medicine, Section of Endocrinology, ENETS Center of Excellence, Erasmus MC and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Tessa Brabander
- Department of Radiology & Nuclear Medicine, ENETS Center of Excellence, Erasmus MC and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Frederik A Verburg
- Department of Radiology & Nuclear Medicine, ENETS Center of Excellence, Erasmus MC and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Richard A Feelders
- Department of Internal Medicine, Section of Endocrinology, ENETS Center of Excellence, Erasmus MC and Erasmus Cancer Institute, Rotterdam, The Netherlands
| | - Wouter W de Herder
- Correspondence: Wouter W. de Herder, MD, PhD, Department of Internal Medicine, Section of Endocrinology, ENETS Center of Excellence, Erasmus MC and Erasmus Cancer Institute, Rotterdam, The Netherlands.
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