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Purpose: To determine prognostic factors and overall survival (OS) in therapy-related myeloid neoplasm (t-MN) of patients after receiving peptide receptor radionuclide therapy (PRRT). Methods: All patients treated from February 1999 until September 2019 at our center who had bone marrow biopsy-proven t-MN after PRRT were included. Patient characteristics, laboratory results, and all tumor-directed therapies before t-MN diagnosis were collected. Cox regression analysis was performed to identify parameters associated with OS. Receiver operating characteristic (ROC) curve analysis was used to define cutoff values as well as sensitivity and specificity of the parameters. Results: Out of 1631 patients treated with PRRT, 30 patients developed t-MN comprising myelodysplastic syndrome (MDS) in 23 patients (77%) and acute myeloid leukemia (AML) in 7 patients (23%). The median OS of t-MN patients was 13 months (range 9.1–16.9 months): 6 months for AML and 15 months for the MDS subgroup, respectively. Higher platelet level was a significant prognostic parameter for longer OS (hazard ratio (HR): 0.99, P < 0.05). Using ROC analysis, the best cutoff value for thrombocyte count was 183.5 Gpt/L, resulting in a sensitivity of 92.3% and a specificity of 50%. Other factors, such as hemoglobin level, did not show a significant correlation with OS. Conclusion: Even rarely occurred, the OS is gravely compromised in t-MN patients after PRRT, and even less in the AML subgroup (6 months). Higher platelet value was a significant prognostic parameter for longer OS in t-MN patients. [ABSTRACT FROM AUTHOR]

Peptide receptor radionuclide therapy (PRRNT) is a molecularly targeted radiation therapy involving the systemic administration of a radiolabelled peptide designed to target with high affinity and specificity receptors overexpressed on tumours. PRRNT employing the radiotagged somatostatin receptor agonists Y-DOTATOC ([Y-DOTA,Tyr]-octreotide) or Lu-DOTATATE ([Lu-DOTA,Tyr,Thr]-octreotide or [Lu-DOTA,Tyr]-octreotate) have been successfully used for the past 15 years to target metastatic or inoperable neuroendocrine tumours expressing the somatostatin receptor subtype 2. Accumulated evidence from clinical experience indicates that these tumours can be subjected to a high absorbed dose which leads to partial or complete objective responses in up to 30 % of treated patients. Survival analyses indicate that patients presenting with high tumour receptor expression at study entry and receiving Lu-DOTATATE or Y-DOTATOC treatment show significantly higher objective responses, leading to longer survival and improved quality of life. Side effects of PRRNT are typically seen in the kidneys and bone marrow. These, however, are usually mild provided adequate protective measures are undertaken. Despite the large body of evidence regarding efficacy and clinical safety, PRRNT is still considered an investigational treatment and its implementation must comply with national legislation, and ethical guidelines concerning human therapeutic investigations. This guidance was formulated based on recent literature and leading experts' opinions. It covers the rationale, indications and contraindications for PRRNT, assessment of treatment response and patient follow-up. This document is aimed at guiding nuclear medicine specialists in selecting likely candidates to receive PRRNT and to deliver the treatment in a safe and effective manner. This document is largely based on the book published through a joint international effort under the auspices of the Nuclear Medicine Section of the International Atomic Energy Agency. [ABSTRACT FROM AUTHOR]

Introduction: Liver transplantation is an important option for patients of neuroendocrine tumors (NET) with metastases limited to the liver. Peptide receptor radionuclide therapy (PRRNT) is effective in the management of metastatic NET. Aim(s): To assess safety and efficacy of PRRNT after liver transplantation in metastatic NET. Materials and methods: This was a retrospective analysis in five patients (age 52±9 years; four males and one female) of NET with progressive extra hepatic metastatic disease after liver transplantation. None of the patients had evidence of recurrent disease in the transplanted liver. The patients received PRRNT with 3, 2, 2, 1 and 2 cycles respectively with Lu-177 alone, the cumulative administered activity ranging from 7.6 to 22.3 GBq after liver transplantation. Results: Three out of the five patients had grade 1 erythrocytopenia and two of the patients showed evidence of grade 1 renal toxicity. Two of the patients had stable disease, while in two patients it continued to progress. The follow-up is awaited in one patient. Conclusion: PRRNT is a safe and effective therapeutic option for progressive disease after liver transplantation in NET. [ABSTRACT FROM AUTHOR]

A correction to the article "The joint IAEA, EANM, and SNMMI practical guidance on peptide receptor radionuclide therapy (PRRNT) in neuroendocrine tumours" that was published in the December 28, 2013 is presented.

Introduction: Hepatic metastases significantly affect the overall prognosis and quality of life in patients with gastroenteropancreatic neuroendocrine tumours (GEP-NET). Radiofrequency ablation (RFA) is one of the important local ablative strategies for hepatic metastases. Peptide receptor radionuclide therapy (PRRNT) is a well-established therapeutic modality for metastatic NET. Aim(s): To assess the efficacy of combined PRRNT and RFA in the management of hepatic metastases of NET. Materials and methods: Nine patients of known metastatic GEP-NET underwent PRRNT (2-5 cycles with Lu-177 and/or Y-90 labeled DOTATATE/DOTATOC) before or after RFA for hepatic metastases. All patients had undergone SSTR PET/CT using Ga-68 DOTATOC before and after the therapies and also for follow-up. Results: In four out of the 10 patients, there was a complete remission over a follow-up period of respectively 36 months, 16 months, nine months and six months, one patient had partial remission over 18 months and one patient stable disease over 30 month follow-up period to date. However in three patients, the disease continued to progress. On retrospective analysis, two out of these patients had intermediate grade NET and one had high grade NET. Conclusion: PRRNT in combination with RFA is effective in the management of hepatic metastases in GEP-NET. [ABSTRACT FROM AUTHOR]

Introduction: Peptide receptor radionuclide therapy is an effective treatment option for patients with well-differentiated somatostatin receptor expressing neuroendocrine tumors. However, published data results mainly from retrospective monocentric studies. Aim(s): We initiated a multi-institutional, prospective and board reviewed registry for patients treated with Peptide receptor radionuclide therapy in Germany in 2009. Materials and methods: In five centers, 297 patients were registered. Primary tumors were mainly derived from the pancreas (117/297), small intestine (80/297) whereas 56 were of unknown primary. Most tumors were well-differentiated with a median Ki-67 proliferation rate of 5% (range 0.9 to 70). Peptide receptor radionuclide therapy was performed using mainly Yttrium-90 and/or Lutetium-177 as radionuclides in 1-8 cycles. Results: Mean overall survival was estimated at 213 months with a follow-up between one and 230 months after initial diagnosis and 87 months with a follow-up between 1 and 92 months after start of Peptide receptor radionuclide therapy. Median overall survival was not yet reached. Subgroup analysis demonstrated that best results were obtained in neuroendocrine tumors with a proliferation rate below 20%. Conclusion: Peptide receptor radionuclide therapy is an effective treatment for well-and moderately differentiated neuroendocrine tumors irrespective of previous therapies and should be regarded as one of the primary treatment options for patients with neuroendocrine tumors. [ABSTRACT FROM AUTHOR]

The heterogeneous nature of the neuroendocrine tumors (NET) makes it challenging to find one uniformly applicable management protocol which is especially true for diagnosis. The discovery of the overexpression of somatostatin receptors (SMS-R) on neuroendocrine tumor cells lead to the generalized and rapid acceptance of radiolabeled somatostatin receptor analogs for staging and restaging of NET as well as for Peptide Receptor Radionuclide Therapy (PRRNT) using Y-90 and Lu- 177 DOTATATE/DOTATOC. In this present work we tried to look in to the effect of PRRNT on the glucose metabolism assessed by F-18 FDG PET/CT and SMS-R density assessed by Ga-68 DOTANOC PET/CT. We observed a complex relationship between the somatostatin receptor expression and glucose metabolism with only 56% (77/138) of the lesions showing match, while the others show mismatch between the receptor status and metabolism. The match between receptor expression and glucose metabolism increases with the grade of NET. In grade 3 NET, there is a concurrence between the changes in glucose metabolism and somatostatin receptor expression. PRRNT was found to be more effective in lesions with higher receptor expression. [ABSTRACT FROM AUTHOR]