Search Results (114)

Background and Objectives: Peptide receptor radionuclide therapy (PRRT) using radiopharmaceuticals labelled with Lutetium-177 is currently a therapeutic option for patients with advanced neuroendocrine neoplasms overexpressing somatostatin receptors (SSTRs). One promising option that has gained interest for PRRT is using alpha-emitting radioisotopes such as Actinium-225. The aim of this study was to perform a systematic review and meta-analysis on the efficacy and safety of radioligand therapy with Actinium-225 DOTATATE in advanced, metastatic or inoperable neuroendocrine neoplasms. Materials and Methods: A comprehensive literature search of studies on radioligand therapy with Actinium-225 DOTATATE in neuroendocrine neoplasms was carried out. Three different bibliographic databases (Cochrane Library, Embase, and PubMed/MEDLINE) were screened up to May 2025. Eligible articles were selected, relevant data were extracted, and the main findings on efficacy and safety are summarized through a systematic review. Furthermore, proportional meta-analyses on the disease response rate and disease control rate were performed. Results: Five studies (153 patients) published from 2020 were included in the systematic review. The pooled disease response rate and disease control rate of radioligand therapy using Actinium-225 DOTATATE were 51.6% and 88%, respectively. This treatment was well-tolerated in most patients with advanced, metastatic or inoperable neuroendocrine neoplasms. Conclusions: Radioligand therapy with Actinium-225 DOTATATE in advanced, metastatic or inoperable neuroendocrine neoplasms is effective with an acceptable toxicity profile and potential advantages compared with SSTR-ligands labelled with Lutetium-177. Currently, the number of published studies on this treatment is still limited, and results from multicenter randomized controlled trials are needed to translate this therapeutic option into clinical practice. Full article

Background: Pancreatic neuroendocrine tumors (PanNETs) are relatively rare neoplasms with heterogeneous behavior, ranging from indolent to aggressive disease. The evolution of nuclear medicine has allowed the development of an efficient and advanced toolkit for the diagnosis and treatment of PanNETs. Case: A 45-year-old woman was diagnosed with a grade 1 PanNET and multiple liver metastases. She underwent distal pancreatectomy with splenectomy, extended liver resection, and radiofrequency ablation (RFA). Surgical planning was guided by [^99mTc]Tc-EDDA/HYNIC-TOC SPECT/CT (single-photon emission computed tomography/computed tomography) and preoperative [^99mTc]Tc-mebrofenin-based functional liver volumetry. Functional liver volumetry based on dynamic [^99mTc]Tc-mebrofenin SPECT/CT facilitated precise surgical planning and reliable assessment of the efficacy of parenchymal modulation, thereby aiding in the prevention of post-hepatectomy liver failure. Liver fibrosis was non-invasively evaluated using two-dimensional shear wave elastography (2D-SWE). Tumor progression was monitored using somatostatin receptor scintigraphy, chromogranin A, and contrast-enhanced CT. Recurrent disease was treated with somatostatin analogues (SSAs) and [¹⁷⁷Lu]Lu-DOTA-TATE peptide receptor radionuclide therapy (PRRT). Despite progression to grade 3 disease (Ki-67 from 1% to 30%), the patient remains alive 53 months post-diagnosis, in complete remission, with an ECOG (Eastern Cooperative Oncology Group) status of 0. Conclusions: Functional imaging played a pivotal role in guiding therapeutic decisions throughout the disease course. This case not only underscores the clinical utility of advanced nuclear imaging but also illustrates the dynamic nature of pancreatic neuroendocrine tumors. The transition from low-grade to high-grade disease highlights the need for further studies on tumor progression mechanisms and the potential role of adjuvant therapies in managing PanNETs. Full article

Background: Peptide receptor radionuclide therapy (PRRT) could be a therapeutic option for patients with advanced, recurrent or progressing meningiomas overexpressing somatostatin receptors. The aim of this study is to perform an updated meta-analysis to establish the disease control rate of PRRT in these patients. Methods: A comprehensive literature search of studies on PRRT in patients with advanced, recurrent or progressing meningioma was carried out. Four different databases (PubMed/MEDLINE, EMBASE, Cochrane library, Google Scholar) were screened until April 2025. Only original articles about PRRT in advanced, progressive or refractory meningiomas were selected. Case reports were excluded. Three review authors independently performed the literature search, the article selection and the data extraction. Main findings of eligible studies were summarized and a proportion meta-analysis on the disease control rate was carried out using a random-effects model. Results: In total, 18 studies (269 patients) published from 2006 to 2025 were included in the analysis. In most of the included studies, PRRT was performed using [¹⁷⁷Lu]Lu-DOTATATE. The pooled disease control rate was 67.7% (95% confidence interval values: 59.6–75.7%). PRRT was well-tolerated in most patients with advanced, recurrent or progressive meningioma. Moderate statistical heterogeneity was found in the meta-analysis (I-square: 53%). Conclusions: PRRT is an effective and well-tolerated treatment in patients with advanced, progressive or recurrent meningiomas, showing a significant disease control rate (in about two-thirds of patients). Even if well-designed clinical trials are needed to corroborate these findings, evidence-based data seem to support the clinical use of PRRT for this indication. Full article

Background: Thymic carcinoids are rare neuroendocrine tumors arising in the anterior mediastinum, often diagnosed at an advanced stage due to nonspecific clinical manifestations. Their management remains challenging because of the paucity of data, rarity of occurrence, and aggressive biological behavior compared to other well-differentiated neuroendocrine neoplasms. Methods: We conducted a comprehensive review of the current literature focusing on the classification, clinical presentation, diagnostics, treatment options, prognostic factors, and emerging experimental therapies for thymic carcinoids. Emphasis was placed on integrating recent molecular and therapeutic advances into clinical practice. Results: Surgical resection remains the cornerstone of treatment for localized disease, while systemic therapies such as everolimus, somatostatin analogs, platinum-based chemotherapy, and peptide receptor radionuclide therapy (PRRT) are options for advanced cases. Novel diagnostic modalities, including NETest, 64Cu-DOTATATE PET, and 18F-FDOPA PET, offer promise in early detection and disease monitoring. Molecular insights, particularly involving MEN1, ATRX, and DAXX mutations, pave the way for individualized targeted therapies. Immunotherapy and radioimmunotherapy represent emerging, albeit still experimental, approaches. Prognosis largely depends on tumor stage, differentiation, resectability, and functional activity, with a high recurrence rate necessitating prolonged surveillance. Conclusions: Thymic carcinoids pose significant diagnostic and therapeutic challenges. Advances in molecular profiling, novel imaging techniques, and systemic therapies offer hope for improved outcomes. Given the disease rarity, continued collaboration through registries and multicenter studies is essential to refine evidence-based management strategies. Full article

Pancreatic neuroendocrine tumors (PNETs) are a rare subset of pancreatic neoplasms with diverse biological behavior and clinical presentations. Traditional treatment approaches, such as surgery and targeted therapies, have significantly improved outcomes. However, advancements in molecular biology, immunotherapy, and minimally invasive techniques have ushered in a new era of treatment possibilities. This manuscript explores the emerging modalities in PNET management, emphasizing the need for a multidisciplinary approach tailored to individual patient profiles. Full article

Background/Objectives: Peptide Receptor Radionuclide Therapy (PRRT) is approved for patients with inoperable, progressive and/or metastatic well-differentiated NETs. Before the approval of Lutathera^®, locally manufactured ¹⁷⁷Lu-HA-DOTATATE was used on a regular basis in clinical routine. The aim of this study was (1) to compare the hematotoxicity of locally manufactured ¹⁷⁷Lu-HA-DOTATATE with Lutathera^® in GEP-NET patients and (2) to compare the recommended treatment interval of 8 weeks between each cycle to a prolonged scheme of up to 11 weeks for both ¹⁷⁷Lu-HA-DOTATATE and Lutathera^®. Methods: The included patients with GEP NETs (n = 46) received four cycles of PRRT, either ¹⁷⁷Lu-HA-DOTATATE or Lutathera^®, and were divided into four subgroups. The subgroups were treated with either locally manufactured ¹⁷⁷Lu-HA-DOTATATE or Lutathera^® and were stratified into a mean application interval of 8 (HA_8weeks, n = 10/Lutathera_8weeks, n = 16) or 11 weeks (HA_adapted, n = 10/Lutathera_adapted, n = 10). To evaluate therapy associated hemato- and nephrotoxicity, patients underwent two laboratory follow-up examinations (follow-up 1—between 2./3. therapy cycle; follow-up 2—after the termination of the 4. therapy cycle) and were then compared to pre-PRRT laboratory results. To assess hematological and renal recovery trends, blood values and parameters of kidney function were collected up to 58.9 weeks after PRRT completion. Common Terminology Criteria for Adverse Events version 5.0 (CTCAE v5.0) were used for grading hematological parameters. Results: The occurrence of high-grade adverse events (CTCAE grade 3/4) after PRRT was moderate, with 1/10 (10%) grade 4 lymphocytopenia in the Lutathera_adapted group, while overall, 20/46 (43.5%) patients had grade 3 lymphocytopenia. Grade 3 thrombocytopenia occurred in 1/10 (10%) patients of the HA_adapted group. Absolute and percentage changes in the kidney function (creatinine, TER) remained constant during PRRT in all subgroups. All four subgroups showed a significant decrease in absolute blood value changes for PLT counts, WBC counts, neutrophil granulocytes and lymphocytes between, prior to and after PRRT (p < 0.05, each). Regarding percentage changes in laboratory parameters, only the HA_adapted and the HA_8weeks groups had significant decreases in WBC (p < 0.03, each) and PLT counts (p < 0.04, each) while there was no significant degradation of any other hematological parameter in any of the subgroups. Only patients with longer treatment intervals under ¹⁷⁷Lu-HA-DOTATATE therapy showed a statistically significant correlation in the long-term recovery analysis concerning the PLT counts (r = 0.6, p < 0.0001). Other blood and kidney values showed no significant correlation in the long-term analysis in the other subgroups. Conclusion: Comparing the hematotoxicity in patients that were treated with locally manufactured ¹⁷⁷Lu-HA-DOTATATE with patients that were treated with Lutathera^® and assessing different treatment intervals in both groups (8 vs. 11 weeks), revealed that there is overall a low to moderate incidence of significant changes in hematological and renal parameters directly after PRRT. Recovery trends of hematological and renal parameters after 1 year suggest that patients treated with locally manufactured ¹⁷⁷Lu-HA-DOTATATE might benefit from a longer treatment interval of 11 weeks regarding their PLT counts. Given the risk of developing hematological diseases such as therapy-related myeloid neoplasms years after PRRT, longer observational periods after PRRT will be crucial. Full article

Meningiomas arise from the meningeal layers covering the central nervous system structures. Although most are benign, meningiomas can still cause neurological morbidity due to the mass effect and compression of the surrounding parenchyma. The prognosis also depends on several factors such as growth pattern or location. Morphological imaging approaches, such as MRI and CT, that emphasize intracranial calcifications, vascular patterns, or invasion of major vessels act as the basis of the diagnosis; PET/CT imaging is a valuable diagnostic tool for assessing somatostatin receptor activity in tumors. It enables the visualization and quantification of somatostatin receptor expression, providing insights into tumor biology, receptor status, and potential therapeutic targets. Aside from radiosurgery and neurosurgical intervention, peptide receptor radionuclide therapy (PRRT) has also shown promising results. Somatostatin receptors 1 and 2 are nearly universally expressed in meningioma tissue. This characteristic is increasingly exploited to identify patients eligible for adjuvant therapy using DOTA-conjugated somatostatin receptor-targeting peptides PET. In the treatment of relapsed/refractory meningiomas, PRRT is increasingly considered a safe and effective therapeutic option. It is often supported by artificial intelligence strategies for dose optimization and side-effect monitoring. The objective of this study is to evaluate the safety and benefits of these strategies based on the latest findings. Full article

Background. Neuroendocrine neoplasms (NENs) represent a heterogeneous group of tumors that pose significant therapeutic challenges due to their potential for progression, metastasis, and hormonal syndromes. Somatostatin analogs (SSAs) have emerged as a cornerstone in NEN treatment, offering both antisecretory and antiproliferative effects by targeting somatostatin receptors (SSTRs). Despite their proven efficacy, intrinsic and acquired resistance mechanisms, including receptor downregulation, tumor heterogeneity, and microenvironmental influences, limit their long-term effectiveness. Recent advances, including high-dose SSA regimens and novel formulations, have aimed to optimize their therapeutic utility and address these limitations. Body of the review. This review explores the cellular and molecular mechanisms underlying the antitumor effects of SSAs, including receptor-mediated signaling pathways, cell cycle arrest, apoptosis induction, and antiangiogenesis. The role of SSAs in combination therapies with mTOR inhibitors and peptide receptor radionuclide therapy (PRRT) is analyzed, emphasizing their synergistic potential. Key clinical trials, such as RADIANT-2, EVERLAR, and NETTER-1, support the efficacy of these approaches, demonstrating improved outcomes when SSAs are combined with targeted agents or radiolabeled therapies. Emerging strategies include high-dose SSA regimens, particularly in progressive cases with low Ki67 indices. Finally, novel formulations, including oral octreotide, paltusotine, and subcutaneous depot formulations like CAM2029, offer improved pharmacokinetics, bioavailability, and patient adherence. Ongoing clinical trials, including SORENTO, further evaluate their efficacy and safety profiles. Conclusions. This paper provides a comprehensive analysis of the cellular and molecular mechanisms of SSAs. SSAs remain integral to the management of NENs, providing effective tumor stabilization and symptom control. However, resistance mechanisms and tumor heterogeneity necessitate innovative approaches, including high-dose regimens, combination strategies, and next-generation formulations. Future research should focus on refining these strategies to optimize patient outcomes, enhance long-term efficacy, and expand the therapeutic landscape for NENs. Full article

Pancreatic neuroendocrine tumors (pNETs) are rare but increasingly prevalent malignancies with varied prognoses and a diverse range of treatment options, including surgery, somatostatin analogues (SSAs), chemotherapy, targeted therapy, and peptide receptor radionuclide therapy (PRRT). This retrospective cohort study analyzed treatment patterns among 189 pNET patients treated between January 2010 and June 2021 at two Canadian cancer centres: the Verspeeten Family Cancer Centre (VFCC), which offers PRRT, and the Ottawa Hospital Cancer Centre (TOHCC), which does not at the time of the study. Data on demographics, tumor characteristics, and treatment modalities were collected, and statistical analyses were conducted using chi-square, Fisher’s exact test, and the Kruskal–Wallis test. Among eligible patients, 53% presented with stage IV disease. Surgical resection was the most common treatment, followed by SSAs, chemotherapy, PRRT, and targeted therapy. Stage IV patients at VFCC were significantly more likely to receive PRRT (60%) compared to TOHCC (6%) and underwent more PRRT cycles, with a higher prevalence of well-differentiated tumors observed at VFCC. With these differences it was clear that the non-PRRT centre was unable to provide patients with the same level of PRRT access during the study period compared to patients seen at the PRRT site. The findings underscore the critical role of PRRT availability in influencing treatment patterns and highlight the need for equitable access to specialized therapies across Canada to optimize outcomes for pNET patients. Full article

Objective: Currently, ⁶⁸Ga-labeled somatostatin analogs (SSAs) are the most commonly used imaging agents for patients with neuroendocrine tumors (NETs) in clinical practice, demonstrating good results in tumor diagnosis. For applications in peptide receptor radionuclide therapy (PRRT), targeted drugs should have high tumor uptake and prolonged tumor retention time. To enhance the uptake and retention of tracers in NETs, our goal is to design a ⁶⁸Ga-labeled heterodimer for optimizing pharmacokinetics and assess whether this form is more efficacious than its monomeric equivalents. Methods: Using the somatostatin analog TATE and quinoline-based compound FAPI-46 as raw materials, we designed and synthesized ⁶⁸Ga-labeled TATE-46. The labeling efficiency and stability were verified by Radio-HPLC. The receptor binding properties and tumor targeting were examined both in vitro and in vivo by using NCI-H727 (SSTR2/FAP, positive) and Mc38 (SSTR2/FAP, negative) cell lines and tumor-bearing mouse models. Preclinical evaluation was performed through cell uptake, pharmacokinetics, Micro PET, and biodistribution studies, and the results were compared with [⁶⁸Ga]Ga-DOTA-TATE and [⁶⁸Ga]Ga -FAPI-46. Immunohistochemistry and HE staining were performed on tumor tissues from tumor-bearing mice for further validation. Results: [⁶⁸Ga]Ga-TATE-46 showed comparable SSTR2 and FAP targeting ability to monomeric TATE and FAPI-46 in cell uptake and PET imaging studies. [⁶⁸Ga]Ga-TATE-46 exhibited significantly higher uptake in NCI-H727 (SSTR2/FAP, positive) tumors compared to [⁶⁸Ga]Ga-DOTA-TATE (p < 0.001) and [⁶⁸Ga]Ga-FAPI-46 (p < 0.001). No increased uptake of [⁶⁸Ga]Ga-TATE-46 was observed in MC38 tumors (SSTR2/FAP, negative). Additionally, excess DOTA-TATE and/or unlabeled FAPI-46 significantly blocked the uptake of [⁶⁸Ga]Ga-TATE-46 in NCI-H727 tumors (p < 0.001), confirming its dual-receptor targeting characteristics. The ex vivo biodistribution, immunofluorescence and immunohistochemistry results were in line with the in vivo imaging findings. Conclusion: Compared with ⁶⁸Ga-labeled FAPI-46 and DOTA-TATE mono-specific tracers, the dual-target tracer [⁶⁸Ga]Ga-TATE-46 improves tumor uptake, extends tumor retention, and enhances pharmacokinetics. It is an effective probe for non-invasive detection of tumors expressing FAP and SSTR2, and it is worth further studying its application in the expression of sstr2 and FAP-related tumors. Full article

We present the case of a 60-year-old male with recurrent atypical meningioma in the right parietal lobe, previously treated with surgery and radiation therapy. Magnetic resonance imaging (MRI) performed 5 years after radiation therapy suggested a possible recurrence. A somatostatin receptor positron emission tomography/computed tomography (SR-PET/CT) scan with Gallium-68 DOTATATE was performed to confirm this suspicion. SR-PET/CT confirmed the presence of recurrent meningioma, showing a novel “rosary sign” with multiple adjacent areas of focal tracer uptake along the resection margins of the previous surgical site in the right parietal region. This novel imaging pattern improved diagnostic accuracy by detailing disease extent and identifying additional lesions not visible via MRI. Given the failure of prior treatments and high SR expression, peptide receptor radionuclide therapy (PRRT) was proposed as a therapeutic option for the patient. Full article

Carcinoid syndrome (CS) is a rare condition associated with neuroendocrine tumors (NETs), particularly those originating in the gastrointestinal tract, which secrete bioactive substances like serotonin. The management of CS requires a multidisciplinary approach due to its complex clinical manifestations, including flushing, diarrhea, bronchospasm, and carcinoid heart disease. Optimal care involves collaboration between several professional figures like oncologists, endocrinologists, gastroenterologists, surgeons, and dietitians. Currently, a wide range of treatments are available, focused on both symptom control and tumor burden reduction. Somatostatin analogs (SSAs) are the first-line therapy for symptom relief. Still, in patients with progressive disease or refractory CS, other options include targeted therapies, peptide receptor radionuclide therapy (PRRT), liver-directed therapies, and surgical resection, when feasible. Furthermore, management of complications related to prolonged serotonin release and malnutrition as a result of exocrine pancreatic insufficiency, post-surgical conditions, vitamin deficit, and chronic diarrhea often requires early detection to mitigate symptoms and improve the quality of life in these patients. The complexity of CS necessitates individualized care and continuous coordination among specialists to optimize outcomes and enhance patient well-being. Full article

Background: Atherosclerosis and its sequels, such as coronary artery disease and cerebrovascular stroke, still represent global health burdens. The pathogenesis of atherosclerosis consists of growing calcified plaques in the arterial wall and is accompanied by inflammatory processes, which are not entirely understood. This study aims to evaluate the effect of peptide receptor radionuclide therapy (PRRT) using ⁹⁰Y- and ¹⁷⁷Lu-DOTATATE on atherosclerotic plaque inflammation. Methods: Atherosclerotic plaques in 57 cancer patients receiving PRRT using ⁹⁰Y- and ¹⁷⁷Lu-DOTATATE were longitudinally monitored by ⁶⁸Ga-DOTATATE PET/CT. The target-to-background ratio (TBR) and overall vessel uptake (OVU) were measured in eight distinct arterial regions (ascending aorta, aortic arch, descending aorta, abdominal aorta, both iliac arteries, and both carotid arteries) to monitor calcified plaques. Results: PET/CT analysis shows a positive correlation between calcified plaque scores and the ⁶⁸Ga-DOTATATE overall vessel uptake (OVU) in cancer patients. After PRRT, an initially high OVU was observed to decrease in the therapy group compared to the control group. An excellent correlation could be shown for each target-to-background ratio (TBR) to the OVU, especially the ascending aorta. Conclusions: The ascending aorta could present a future reference for estimating generalized atherosclerotic inflammatory processes. PRRT might represent a therapeutic approach to modulating atherosclerotic plaques. Full article

The poor prognosis of pancreatic cancer requires novel treatment options. This review examines the evolution of radiopharmaceuticals in the treatment of pancreatic cancer. Established strategies such as peptide receptor radionuclide therapy (PRRT) offer targeted and effective treatment, compared to conventional treatments. However, there are currently no radiopharmaceuticals approved for the treatment of pancreatic cancer in Europe, which requires further research and novel approaches. New radiopharmaceuticals including radiolabeled antibodies, peptides, and nanotechnological approaches are promising in addressing the challenges of pancreatic cancer therapy. These new agents may offer more specific targeting and potentially improve efficacy compared to traditional therapies. Further research is needed to optimize efficacy, address limitations, and explore the overall potential of these new strategies in the treatment of this aggressive and harmful pathology. Full article

The aim of the present study was to evaluate the safety and efficacy of radionuclide therapy with [¹⁷⁷Lu]Lu-DOTA-TATE according to our single center experience at the University of Naples Federico II. For the present analysis, we considered 21 patients with progressive, advanced, well-differentiated G1 and G2 in patients with gastro-entero-pancreatic (GEP) neuroendocrine tumors (NETs) treated with [¹⁷⁷Lu]Lu-DOTA-TATE according to the decisions of a multidisciplinary team. All patients underwent four cycles of 7–8 GBq of [¹⁷⁷Lu]Lu-DOTA-TATE every 8 weeks. A whole-body scan (WBS) was performed 4, 48, and 168 h after each treatment. The dosimetry towards the organ at risk and target lesions was calculated. For each patient, renal and bone marrow parameters were evaluated before, during, and 3 months after the end of the treatment. Follow-up data were obtained and RECIST criteria were considered as the endpoint. Among 21 patients enrolled (mean age 65 ± 9 years); 17 (81%) were men and the small intestine was the most frequent location of disease (n = 12). A mild albeit significant variation (p < 0.05) in both platelets and white blood cell counts among all time points was observed, despite it disappearing 3 months after the end of the therapy. According to the RECIST criteria, 11 (55%) patients had a partial response to therapy and 8 (40%) had stable disease. Only one (5%) patient had disease progression 4 months after treatment. Our data confirm that [¹⁷⁷Lu]Lu-DOTA is safe and effective in controlling the burden disease of G1/G2 GEP-NETs patients. Full article