Net theranostics

Large Neuroendocrine Neoplasms of the Duodenum: Description of Two Rare Subtypes and Technical Details on Surgical Treatment

BACKGROUND

Duodenal neuroendocrine tumors (NETs) are uncommon, accounting for less than 4% of all gastrointestinal neoplasms. Prognosis is related to tumoral staging and grading, as well as to the specific subtype. In this article, we retrospectively describe the clinical presentation and surgical treatment of two rare large duodenal NETs: a high-grade G3 NET and a Gangliocytic Paraganglioma (GP).

METHODS

Both patients presented with moderate-to-high-degree abdominal pain, without jaundice. Main vessel involvement and metastatic spread were excluded with imaging, while preoperative bioptic diagnosis was obtained via percutaneous needle citology and endoscopic ultrasound.

RESULTS

The presence of a sessile large lesion contraindicated any conservative approach in favor of a pancreaticoduodenectomy (PD). The detection of soft pancreatic tissue and a narrowed main pancreatic duct led us to perform a pancreaticogastrostomy to restore proper pancreatic drainage and to minimize the risk of postoperative leakage.

CONCLUSION

PD may be a favorable choice in these cases; this procedure is challenging, but it results in a safer and more favorable clinical outcome for our patients. Pancreaticogastrostomy may guarantee lower rates of postoperative leak and appears to be preferred in this subset of patients.

Gastroenteropancreatic neuroendocrine neoplasms: epidemiology, genetics, and treatment

The incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) is increasing at a rapid pace and is becoming an increasingly important consideration in clinical care. Epidemiological data from multiple countries indicate that the incidence of gastroenteropancreatic neuroendocrine neoplasms (GEP NEN) exhibits regional, site-specific, and gender-based variations. While the genetics and pathogenesis of some GEP NEN, particularly pancreatic NENs, have been investigated, there are still many mechanisms that require further investigation. The management of GEP NEN is diverse, but surgery remains the primary option for most cases. Peptide receptor radionuclide therapy (PRRT) is an effective treatment, and several clinical trials are exploring the potential of immunotherapy and targeted therapy, as well as combination therapy.

Comparison of 18F-FDG PET/CT and 18F-DOTATATE PET/CT in the diagnosis of multiple metastases in rectal neuroendocrine neoplasms

This case report describes a 62-year-old male with a notable medical history, including surgically treated bladder cancer and the suspicion of metastatic disease. He underwent 18F-FDG PET/CT imaging as part of the initial diagnostic workup, which identified several marginally hypodense hepatic lesions. These lesions exhibited metabolic activity that was slightly lower than the surrounding hepatic parenchyma, raising concerns for metastatic involvement. Subsequent 18F-DOTATATE PET/CT imaging significantly expanded the diagnostic perspective by identifying multiple somatostatin receptor (SSTR)-positive lesions, not only in the liver but also in lymph nodes and bones. This marked an important diagnostic advancement over the initial FDG PET/CT findings, showcasing the superior sensitivity of 18F-DOTATATE PET/CT in detecting SSTR-expressing tumors. Pathological evaluation after these imaging studies confirmed the diagnosis of a rectal neuroendocrine tumor (NET) with extensive hepatic metastasis, altering the clinical management and therapeutic approach for the patient. This case underscores the pivotal role of integrating 18F-DOTATATE and FDG PET/CT in the diagnostic and therapeutic management of neuroendocrine tumors, highlighting the complementary nature of these imaging modalities. The findings advocate for the use of 18F-DOTATATE PET/CT in cases where NETs are suspected, particularly for its enhanced sensitivity in detecting SSTR-positive lesions across various sites, thereby facilitating a more comprehensive disease assessment and informed therapeutic planning.

Emerging conjugation strategies and protein engineering technologies aim to improve ADCs in the fight against cancer

Antibody drug conjugates are an exciting therapeutic modality that combines the targeting specificity of antibodies with potent cytotoxins to selectively kill cancer cells. The targeting component improves efficacy and protects non-target cells from the harmful effects of the payload. To date 15 ADCs have been approved by regulatory agencies for commercial use and shown to be valuable tools in the treatment of cancer.The assembly of an ADC requires the chemical ligation of a linker-payload to an antibody. Conventional conjugation methods targeting accessible lysines and cysteines have produced all the ADCs currently on the market. While successful, technologies aiming to improve the homogeneity and stability of ADCs are being developed and tested.Here we provide a review of developing methods for ADC construction. These include enzymatic methods, oligosaccharide remodelling, and technologies using genetic code expansion techniques. The virtues and limitations of each technology are discussed.Emerging conjugation technologies are being applied to produce new formats of ADCs with enhanced functionality including bispecific ADCs, dual-payload ADCs, and nanoparticles for targeted drug delivery. The benefits of these novel formats are highlighted.

Current clinical application of lutetium‑177 in solid tumors (Review)

Radionuclide-based therapy represents a novel treatment regimen for tumors. Among these therapies, lutetium-177 (177Lu) has gained significant attention due to its stability and safety, as well as its ability to emit both γ and β rays, allowing for both imaging with single photon emission computed tomography and tumor treatment. As a result, 177Lu can be used for both diagnosis and treatment for diseases such as prostatic and gastric cancer. Therefore, based on the available data, the present review provides a brief overview of the clinical applications of 177Lu-targeted radionuclide therapy in metastatic prostate cancer, neuroendocrine tumors and other types of solid tumors, and highlights the current therapeutic effect, reduction in damage to normal tissues and future research directions, including the development of new nuclides and the application of more nuclides in different tumors. In the future, such treatments could be used in more tumors.

Robotic-assisted partial nephrectomy for a neuroendocrine tumor in a horseshoe kidney: a case report

Neuroendocrine tumors of the kidney are exceedingly rare. We report the first case of robotic-assisted partial nephrectomy for such tumors in horseshoe kidneys. A 65-year-old woman was incidentally found to have a 27 mm renal mass in the isthmus of her horseshoe kidney during computed tomography. Based on contrast-enhanced computed tomography results, we initially suspected renal cell carcinoma originating from the horseshoe kidney. Subsequently, robotic-assisted partial nephrectomy with isthmus transection was performed. Intraoperatively, we adjusted the port position for camera insertion and the patient's positioning to facilitate better visualization for dorsal isthmus and vessel dissection. Pathological examination and immunohistochemical analysis revealed a well-differentiated neuroendocrine tumor. Therefore, robotic-assisted partial nephrectomy is a safe and effective approach for managing neuroendocrine tumors in the isthmus of horseshoe kidneys. Given the nonspecific clinical presentation of renal neuroendocrine tumors and their rarity, the optimal management of these tumors remains controversial.

Actinium-225 Targeted Agents: Where Are We Now?

α-particle targeted radionuclide therapy has shown promise for optimal cancer management, an exciting new era for brachytherapy. Alpha-emitting nuclides can have significant advantages over gamma- and beta-emitters due to their high linear energy transfer (LET). While their limited path length results in more specific tumor 0kill with less damage to surrounding normal tissues, their high LET can produce substantially more lethal double strand DNA breaks per radiation track than beta particles. Over the last decade, the physical and chemical attributes of Actinium-225 (225Ac) including its half-life, decay schemes, path length, and straightforward chelation ability has peaked interest for brachytherapy agent development. However, this has been met with challenges including source availability, accurate modeling for standardized dosimetry for brachytherapy treatment planning, and laboratory space allocation in the hospital setting for on-demand radiopharmaceuticals production. Current evidence suggests that a simple empirical approach based on 225Ac administered radioactivity may lead to inconsistent outcomes and toxicity. In this review article, we highlight the recent advances in 225Ac source production, dosimetry modeling, and current clinical studies.

Primary neuroendocrine neoplasms of the kidney: a case report and literature review

Primary kidney neuroendocrine tumors (NETs) are rare renal malignancies. However, detecting and monitoring neuroendocrine neoplasms remains challenging because of their nonspecific nature. We herein present a case involving a 53-year-old woman who experienced episodes of intermittent abdominal pain, dizziness, and nausea for a period of 5 days. Computed tomography urography revealed a small (approximately 19- × 16-mm) nodular shadow in the left kidney. The nodular shadow exhibited slightly lower density than the surrounding tissue as well as enhancement, with a portion protruding into the renal sinus region. Histological and immunohistochemical analyses of the biopsy specimen from the mass indicated a well-differentiated NET. After analysis of this case, we performed a literature review and herein discuss various techniques for imaging and pathological diagnosis of renal NETs. Additionally, we provide insights into the treatment options and prognosis for affected patients. By combining this case study with the existing published literature, we aim to offer a valuable reference for clinicians treatment patients diagnosed with renal NETs.

Prognostic Implications of PET-Derived Tumor Volume and Uptake in Patients with Neuroendocrine Tumors

Historically, molecular imaging of somatostatin receptor (SSTR) expression in patients with neuroendocrine tumors (NET) was performed using SSTR scintigraphy (SRS). Sustained advances in medical imaging have led to its gradual replacement with SSTR positron-emission tomography (SSTR-PET). The higher sensitivity in comparison to SRS on the one hand and conventional cross-sectional imaging, on the other hand, enables more accurate staging and allows for image quantification. In addition, in recent years, a growing body of evidence has assessed the prognostic implications of SSTR-PET-derived prognostic biomarkers for NET patients, with the aim of risk stratification, outcome prognostication, and prediction of response to peptide receptor radionuclide therapy. In this narrative review, we give an overview of studies examining the prognostic value of advanced SSTR-PET-derived (semi-)quantitative metrics like tumor volume, uptake, and composite metrics. Complementing this analysis, a discussion of the current trends, clinical implications, and future directions is provided.

Comparative evaluation of the structure and antitumor mechanism of mononuclear and trinucleated thiosemicarbazone Cu(II) complexes

The ratio of ligand to Cu(II) ions has an essential effect on the geometrical configuration and anti-tumour activity of metal-based complexes. In this work, we synthesised two Cu(II) thiosemicarbazone complexes, namely, [Cu(L)(Cl)] (C1) and [Cu₃(L)₂(Cl)₄] (C2), by controlling the ratio of Cu(II) ion to ligand, to evaluate their anti-tumour activity. The ability of C1 to catalyze hydrogen peroxide to produce reactive oxygen species (ROS) was significantly higher than that of Cu(II) ion. Moreover, the bridge of Cu(II) and two molecules generated a new complex (C2), which, in contrast to C1, enhanced the generation of Fenton-like-triggered ROS. Consequently, the produced ROS depleted reduced glutathione, caused oxidative cell stress and promoted apoptosis through mitochondrial apoptotic pathways. In addition, C2 exhibited better tumour suppression than C1 in a nude mouse tumour xenograft model.

New anti-cancer explorations based on metal ions

Due to the urgent demand for more anti-cancer methods, the new applications of metal ions in cancer have attracted increasing attention. Especially the three kinds of the new mode of cell death, including ferroptosis, calcicoptosis, and cuproptosis, are of great concern. Meanwhile, many metal ions have been found to induce cell death through different approaches, such as interfering with osmotic pressure, triggering biocatalysis, activating immune pathways, and generating the prooxidant effect. Therefore, varieties of new strategies based on the above approaches have been studied and applied for anti-cancer applications. Moreover, many contrast agents based on metal ions have gradually become the core components of the bioimaging technologies, such as MRI, CT, and fluorescence imaging, which exhibit guiding significance for cancer diagnosis. Besides, the new nano-theranostic platforms based on metal ions have experimentally shown efficient response to endogenous and exogenous stimuli, which realizes simultaneous cancer therapy and diagnosis through a more controlled nano-system. However, most metal-based agents have still been in the early stages, and controlled clinical trials are necessary to confirm or not the current expectations. This article will focus on these new explorations based on metal ions, hoping to provide some theoretical support for more anti-cancer ideas.