Lutetium-177-PSMA-617 for Metastatic Castration-Resistant Prostate Cancer.

BACKGROUND: Metastatic castration-resistant prostate cancer remains fatal despite recent advances. Prostate-specific membrane antigen (PSMA) is highly expressed in metastatic castration-resistant prostate cancer. Lutetium-177 (177Lu)-PSMA-617 is a radioligand therapy that delivers beta-particle radiation to PSMA-expressing cells and the surrounding microenvironment. METHODS: We conducted an international, open-label, phase 3 trial evaluating 177Lu-PSMA-617 in patients who had metastatic castration-resistant prostate cancer previously treated with at least one androgen-receptor-pathway inhibitor and one or two taxane regimens and who had PSMA-positive gallium-68 (68Ga)-labeled PSMA-11 positron-emission tomographic-computed tomographic scans. Patients were randomly assigned in a 2:1 ratio to receive either 177Lu-PSMA-617 (7.4 GBq every 6 weeks for four to six cycles) plus protocol-permitted standard care or standard care alone. Protocol-permitted standard care excluded chemotherapy, immunotherapy, radium-223 (223Ra), and investigational drugs. The alternate primary end points were imaging-based progression-free survival and overall survival, which were powered for hazard ratios of 0.67 and 0.73, respectively. Key secondary end points were objective response, disease control, and time to symptomatic skeletal events. Adverse events during treatment were those occurring no more than 30 days after the last dose and before subsequent anticancer treatment. RESULTS: From June 2018 to mid-October 2019, a total of 831 of 1179 screened patients underwent randomization. The baseline characteristics of the patients were balanced between the groups. The median follow-up was 20.9 months. 177Lu-PSMA-617 plus standard care significantly prolonged, as compared with standard care, both imaging-based progression-free survival (median, 8.7 vs. 3.4 months; hazard ratio for progression or death, 0.40; 99.2% confidence interval [CI], 0.29 to 0.57; P<0.001) and overall survival (median, 15.3 vs. 11.3 months; hazard ratio for death, 0.62; 95% CI, 0.52 to 0.74; P<0.001). All the key secondary end points significantly favored 177Lu-PSMA-617. The incidence of adverse events of grade 3 or above was higher with 177Lu-PSMA-617 than without (52.7% vs. 38.0%), but quality of life was not adversely affected. CONCLUSIONS: Radioligand therapy with 177Lu-PSMA-617 prolonged imaging-based progression-free survival and overall survival when added to standard care in patients with advanced PSMA-positive metastatic castration-resistant prostate cancer. (Funded by Endocyte, a Novartis company; VISION ClinicalTrials.gov number, NCT03511664.).

Radioembolization with Yttrium-90 Glass Microspheres as a First-Line Treatment for Unresectable Intrahepatic Cholangiocarcinoma-A Prospective Feasibility Study.

PURPOSE: To evaluate the safety and effectiveness of yttrium-90 (90Y) radioembolization as first-line treatment for unresectable intrahepatic cholangiocarcinoma (ICC). MATERIALS AND METHODS: This prospective study enrolled patients who had never received chemotherapy, liver embolization, and radiation therapy. The tumors were solitary in 16 patients, multiple in 8 patients, unilobar in 14 patients, and bilobar in 10 patients. Patients underwent transarterial radioembolization with 90Y-labeled glass microspheres. The primary end point was hepatic progression-free survival (HPFS). Secondary end points were overall survival (OS), tumor response, and toxicity. RESULTS: Twenty-four patients (age, 72.3 years ± 9.3; 12 women) were included in the study. The median delivered radiation dose was 135.5 Gy (interquartile range, 77.6 Gy). The median HPFS was 5.5 months (95% CI, 3.9-7.0 months). Analysis failed to identify any prognostic factor associated with HPFS. Imaging response at 3 months showed 56% disease control, and the best radiographic response was 71% disease control. The median OS from the radioembolization treatment was 19.4 months (95% CI, 5.0-33.7). Patients with solitary ICC had significantly longer median OS than patients with multifocal ICC: 25.9 months (95% CI, 20.8-31.0 months) versus 10.7 months (95% CI, 8.0-13.4 months) (P = .02). Patients with progression on the 3-month imaging follow-up had significantly shorter median OS than patients who had stable disease at 3 months: 10.7 months (95% CI, 0.7-20.7 months) versus 37.3 months (95% CI, 16.5-58.1 months) (P = .003). Two (8%) Grade 3 toxicities were reported. CONCLUSIONS: First-line treatment of ICC with radioembolization showed promising OS and minimal toxicity, especially in patients with solitary tumor. Radioembolization may be considered as a first-line treatment option for unresectable ICC.

Imaging of Neuroendocrine Neoplasms: Monitoring Treatment Response-AJR Expert Panel Narrative Review.

Neuroendocrine neoplasms (NENs) encompass a broad spectrum of tumors throughout the body and range in biologic behavior from indolent to aggressive. Consequently, a wide spectrum of treatment options are available for NENs, including observation, somatostatin analogues, targeted therapy, chemotherapy, surgical resection, liver-directed therapy (embolization and ablation), and peptide receptor radionuclide therapy. Given the wide variety of tumor behaviors and treatments, precise criteria for treatment response in NENs are lacking. Though conventional anatomic imaging with CT and MRI remains important for NEN response assessment, the use of somatostatin receptor (SSR) PET is increasing and often provides synergistic and complementary information. Additionally, in certain clinical scenarios, a particular imaging strategy may prove superior or inferior to others for the detection of metastatic disease and evaluation of therapy response. A strong need exists to further define appropriate and standardized assessment criteria for tumor response and progression in NEN. This article presents the strengths and weaknesses of individual imaging modalities for evaluating NEN therapy response, including conventional anatomic imaging, SSR PET, FDG PET, dual-tracer PET, and PET/MRI. Ongoing challenges and unmet needs in the use of imaging for NEN response evaluation are explored.

Preclinical evaluation of [225Ac]Ac-DOTA-TATE for treatment of lung neuroendocrine neoplasms.

PURPOSE: There is significant interest in the development of targeted alpha-particle therapies (TATs) for treatment of solid tumors. The metal chelator-peptide conjugate, DOTA-TATE, loaded with the ß-particle emitting radionuclide 177Lu ([177Lu]Lu-DOTA-TATE) is now standard care for neuroendocrine tumors that express the somatostatin receptor 2 (SSTR2) target. A recent clinical study demonstrated efficacy of the corresponding [225Ac]Ac-DOTA-TATE in patients that were refractory to [177Lu]Lu-DOTA-TATE. Herein, we report the radiosynthesis, toxicity, biodistribution (BD), radiation dosimetry (RD), and efficacy of [225Ac]Ac-DOTA-TATE in small animal models of lung neuroendocrine neoplasms (NENs). METHODS: [225Ac]Ac-DOTA-TATE was synthesized and characterized for radiochemical yield, purity and stability. Non-tumor-bearing BALB/c mice were tested for toxicity and BD. Efficacy was determined by single intravenous injection of [225Ac]Ac-DOTA-TATE into SCID mice-bearing human SSTR2 positive H727 and H69 lung NENs. RD was calculated using the BD data. RESULTS: [225Ac]Ac-DOTA-TATE was synthesized with 98% yield, 99.8% purity, and displayed 97% stability after 2 days incubation in human serum at 37 °C. All animals in the toxicity study appeared healthy 5 months post injection with no indications of toxicity, except that animals that received ≥111 kBq of [225Ac]Ac-DOTA-TATE had chronic progressive nephropathy. BD studies revealed that the primary route of elimination is by the renal route. RD calculations determined pharmacokinetics parameters and absorbed α-emission dosages from 225Ac and its daughters. For both tumor models, a significant tumor growth delay and time to experimental endpoint were observed following a single administration of [225Ac]Ac-DOTA-TATE relative to controls. CONCLUSIONS: These results suggest significant potential for the clinical translation of [225Ac]Ac-DOTA-TATE for lung NENs.

Phase 3 Trial of 177Lu-Dotatate for Midgut Neuroendocrine Tumors.

BACKGROUND: Patients with advanced midgut neuroendocrine tumors who have had disease progression during first-line somatostatin analogue therapy have limited therapeutic options. This randomized, controlled trial evaluated the efficacy and safety of lutetium-177 (177Lu)-Dotatate in patients with advanced, progressive, somatostatin-receptor-positive midgut neuroendocrine tumors. METHODS: We randomly assigned 229 patients who had well-differentiated, metastatic midgut neuroendocrine tumors to receive either 177Lu-Dotatate (116 patients) at a dose of 7.4 GBq every 8 weeks (four intravenous infusions, plus best supportive care including octreotide long-acting repeatable [LAR] administered intramuscularly at a dose of 30 mg) (177Lu-Dotatate group) or octreotide LAR alone (113 patients) administered intramuscularly at a dose of 60 mg every 4 weeks (control group). The primary end point was progression-free survival. Secondary end points included the objective response rate, overall survival, safety, and the side-effect profile. The final analysis of overall survival will be conducted in the future as specified in the protocol; a prespecified interim analysis of overall survival was conducted and is reported here. RESULTS: At the data-cutoff date for the primary analysis, the estimated rate of progression-free survival at month 20 was 65.2% (95% confidence interval [CI], 50.0 to 76.8) in the 177Lu-Dotatate group and 10.8% (95% CI, 3.5 to 23.0) in the control group. The response rate was 18% in the 177Lu-Dotatate group versus 3% in the control group (P<0.001). In the planned interim analysis of overall survival, 14 deaths occurred in the 177Lu-Dotatate group and 26 in the control group (P=0.004). Grade 3 or 4 neutropenia, thrombocytopenia, and lymphopenia occurred in 1%, 2%, and 9%, respectively, of patients in the 177Lu-Dotatate group as compared with no patients in the control group, with no evidence of renal toxic effects during the observed time frame. CONCLUSIONS: Treatment with 177Lu-Dotatate resulted in markedly longer progression-free survival and a significantly higher response rate than high-dose octreotide LAR among patients with advanced midgut neuroendocrine tumors. Preliminary evidence of an overall survival benefit was seen in an interim analysis; confirmation will be required in the planned final analysis. Clinically significant myelosuppression occurred in less than 10% of patients in the 177Lu-Dotatate group. (Funded by Advanced Accelerator Applications; NETTER-1 ClinicalTrials.gov number, NCT01578239 ; EudraCT number 2011-005049-11 .).

Transarterial Radioembolization Treatment of Pancreatic Cancer Patients with Liver-Dominant Metastatic Disease Using Yttrium-90 Glass Microspheres: A Single-Institution Retrospective Study.

PURPOSE: To retrospectively evaluate the safety and efficacy of transarterial radioembolization (TARE) with yttrium-90 (90Y)-labeled glass microspheres in pancreatic adenocarcinoma patients with liver-dominant metastatic disease. MATERIALS AND METHODS: This retrospective, single-center study evaluated 26 patients (12 men and 14 women; mean age, 65.5 ± 11.2 years) with liver-dominant metastatic pancreatic cancer who were treated with TARE from April 2010 to September 2017. All patients received systemic chemotherapy before TARE, and 19 received systemic therapy after embolization. Nineteen patients had extrahepatic disease at the time of TARE. Response to treatment was determined by Response Evaluation Criteria in Solid Tumors at 3 months. RESULTS: Median overall survival (OS) from pancreatic cancer diagnosis was 33.0 months (range, 8.5-87.5 months); median OS from diagnosis of liver metastasis was 21.8 months (range, 2.0-86.2 months); and median OS from TARE treatment was 7.0 months (range, 1.0-84.1 months). Grade 1-2 clinical toxicities were noted in 21 patients (80.8%), and 24 patients (92.3%) had grade 1-2 biochemical toxicities. Four patients (15.4%) had grade 3 clinical toxicities, and 6 patients (23.1%) had grade 3 biochemical toxicities. Imaging was available in 22 patients (84.6%) and demonstrated partial response in 1 patient, stable disease in 9 patients, and progressive disease in 12 patients. Improved hepatic progression-free survival was associated in patients younger than 65 years and in those whose carbohydrate antigen 19-9 level decreased or remained stable after treatment. CONCLUSIONS: TARE with 90Y-labeled glass microspheres is safe and led to promising OS in liver-dominant metastatic pancreatic cancer.

Development of Targeted Alpha Particle Therapy for Solid Tumors.

Targeted alpha-particle therapy (TAT) aims to selectively deliver radionuclides emitting α-particles (cytotoxic payload) to tumors by chelation to monoclonal antibodies, peptides or small molecules that recognize tumor-associated antigens or cell-surface receptors. Because of the high linear energy transfer (LET) and short range of alpha (α) particles in tissue, cancer cells can be significantly damaged while causing minimal toxicity to surrounding healthy cells. Recent clinical studies have demonstrated the remarkable efficacy of TAT in the treatment of metastatic, castration-resistant prostate cancer. In this comprehensive review, we discuss the current consensus regarding the properties of the α-particle-emitting radionuclides that are potentially relevant for use in the clinic; the TAT-mediated mechanisms responsible for cell death; the different classes of targeting moieties and radiometal chelators available for TAT development; current approaches to calculating radiation dosimetry for TATs; and lead optimization via medicinal chemistry to improve the TAT radiopharmaceutical properties. We have also summarized the use of TATs in pre-clinical and clinical studies to date.

90Y Radioembolization for Hepatic Malignancy in Patients with Previous Biliary Intervention: Multicenter Analysis of Hepatobiliary Infections.

Purpose To determine the frequency of hepatobiliary infections after transarterial radioembolization (TARE) with yttrium 90 (90Y) in patients with liver malignancy and a history of biliary intervention. Materials and Methods For this retrospective study, records of all consecutive patients with liver malignancy and history of biliary intervention treated with TARE at 14 centers between 2005 and 2015 were reviewed. Data regarding liver function, 90Y dosimetry, antibiotic prophylaxis, and bowel preparation prophylaxis were collected. Primary outcome was development of hepatobiliary infection. Results One hundred twenty-six patients (84 men, 42 women; mean age, 68.8 years) with primary (n = 39) or metastatic (n = 87) liver malignancy and history of biliary intervention underwent 180 procedures with glass (92 procedures) or resin (88 procedures) microspheres. Hepatobiliary infections (liver abscesses in nine patients, cholangitis in five patients) developed in 10 of the 126 patients (7.9%) after 11 of the 180 procedures (6.1%; nine of those procedures were performed with glass microspheres). All patients required hospitalization (median stay, 12 days; range, 2-113 days). Ten patients required percutaneous abscess drainage, three patients underwent endoscopic stent placement and stone removal, and one patient needed insertion of percutaneous biliary drains. Infections resolved in five patients, four patients died (two from infection and two from cancer progression while infection was being treated), and one patient continued to receive suppressive antibiotics. Use of glass microspheres (P = .02), previous liver resection or ablation (P = .02), and younger age (P = .003) were independently predictive of higher infection risk. Conclusion Infectious complications such as liver abscess and cholangitis are uncommon but serious complications of transarterial radioembolization with 90Y in patients with liver malignancy and a history of biliary intervention.

Intrahepatic Cholangiocarcinoma Treated with Transarterial Yttrium-90 Glass Microsphere Radioembolization: Results of a Single Institution Retrospective Study.

PURPOSE: To evaluate the efficacy and safety of transarterial yttrium-90 glass microsphere radioembolization in patients with unresectable intrahepatic cholangiocarcinoma (ICC). MATERIALS AND METHODS: Retrospective review of 85 consecutive patients (41 men and 44 women; age, 73.4 ± 9.3 years) was performed. Survival data were analyzed by the Kaplan-Meier method, Cox regression models, and the log-rank test. RESULTS: Median overall survival (OS) from diagnosis was 21.4 months (95% confidence interval [CI]: 16.6-28.4); median OS from radioembolization was 12.0 months (95% CI: 8.0-15.2). Seven episodes of severe toxicity occurred. At 3 months, 6.2% of patients had partial response, 64.2% had stable disease, and 29.6% had progressive disease. Median OS from radioembolization was significantly longer in patients with Eastern Cooperative Oncology Group (ECOG) scores of 0 and 1 than patients with an ECOG score of 2 (18.5 vs 5.5 months, P = .0012), and median OS from radioembolization was significantly longer in patients with well-differentiated histology than patients with poorly differentiated histology (18.6 vs 9.7 months, P = .012). Patients with solitary tumors had significantly longer median OS from radioembolization than patients with multifocal disease (25 vs. 6.1 months, P = .006). The absence of extrahepatic metastasis was associated with significantly increased median OS (15.2 vs. 6.8 months, P = .003). Increased time from diagnosis to radioembolization was a negative predictor of OS. The morphology of the tumor (mass-forming or infiltrative, hyper- or hypo-enhancing) had no effect on survival. Post-treatment increased cancer antigen 19-9 level, increased international normalized ratio, decreased albumin, increased bilirubin, increased aspartate aminotransferase, and increased Model for End-Stage Liver Disease score were significant predictors of decreased OS. CONCLUSIONS: These data support the therapeutic role of radioembolization for the treatment of unresectable ICC with good efficacy and an acceptable safety profile.

Liver-Directed Therapies for Hepatocellular Carcinoma and Intrahepatic Cholangiocarcinoma.

Hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC) are primary liver cancers where all or most of the tumor burden is usually confined to the liver. Therefore, locoregional liver-directed therapies can provide an opportunity to control intrahepatic disease with minimal systemic side effects. The English medical literature and clinical trials were reviewed to provide a synopsis on the available liver-directed percutaneous therapies for HCC and IHC. Locoregional liver-directed therapies provide survival benefit for patients with HCC and IHC compared to best medical treatment and have lower comorbid risks compared to surgical resection. These treatment options should be considered, especially in patients with unresectable disease.

Transarterial Yttrium-90 Radioembolization Treatment of Patients with Liver-Dominant Metastatic Renal Cell Carcinoma.

PURPOSE: To evaluate safety and efficacy of transarterial hepatic radioembolization treatment of patients with liver-dominant metastatic renal cell carcinoma (RCC). MATERIALS AND METHODS: From July 2010 to December 2014, 18 patients with liver-dominant metastatic RCC were treated with yttrium-90 glass microsphere radioembolization. Retrospective review of medical records and imaging studies was performed to evaluate toxicities, treatment response, and overall survival. The median follow-up period from radioembolization treatment was 17.8 months (range, 3-54.4 months). RESULTS: Median overall survival from RCC diagnosis was 64 months (95% confidence interval [CI], 0-144.1 months), from diagnosis of liver metastasis was 29 months (95% CI, 7.2-50.8 months), and from radioembolization treatment was 22.8 months (95% CI, 13.2-32.3 months). After treatment, 10 patients reported grade 1 clinical toxicities, and 8 patients had grade 1 or 2 biochemical toxicities. The best radiographic responses of 17 patients who underwent contrast-enhanced cross-sectional imaging showed complete response in 16 patients and partial response in 1 patient evaluated by modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria. The last available imaging of these 17 patients demonstrated complete response in 14 patients, partial response in 1 patient, and progression of disease in 2 patients. Images of a patient who underwent noncontrast CT showed stable disease as best response and stable disease on the last available imaging evaluated by RECIST. CONCLUSIONS: Radioembolization is safe and effective and led to improved hepatic disease control and overall survival in patients with liver-dominant metastatic RCC.

Cutaneous Neuroendocrine Metastases of Visceral Origin Responsive to Surgical Resection and Targeted Radionuclide Therapy.

Neuroendocrine neoplasms (NENs) encompass a diverse range of biologically and behaviorally distinct epithelial malignancies that derive from neuroendocrine cells. These neoplasms are able to secrete a variety of bioactive amines or peptide hormones. The majority of NENs are well-differentiated and are defined as neuroendocrine tumors (NETs). While NETs are known to frequently metastasize to lymph nodes, liver, and lungs, spread to the skin is extremely rare and is often a late finding. Because cutaneous metastasis from a visceral site represents distant tumor dissemination, prompt histologic diagnosis is critical in terms of selecting further treatment options and ultimately impacts subsequent prognosis. This report presents a man with painful cutaneous NET metastases initially on the face then scalp. He had a prior history of longstanding and progressive stage IV visceral disease. Multimodal therapy with initial surgical resection of the larger facial lesion and radionuclide infusion therapy was undertaken. Excision fully removed the temple lesion and resolved pain. Peptide receptor radionuclide therapy (PRRT) with 177Lu-DOTATATE, a radiolabeled somatostatin analog that targets somatostatin receptors on NETs, was given along with maintenance lanreotide therapy, which resolved the scalp lesion, prevented recurrence of prior lesions and development of new cutaneous metastases, and controlled his visceral disease. PRRT has not been previously described in the management of cutaneous NET metastases. Due to the rare nature of cutaneous NET metastases, there is no consensus regarding optimal management. As such, we propose novel multimodal therapy involving excision and targeted radionuclide therapy as a possible effective option.

Sequencing of Somatostatin-Receptor-Based Therapies in Neuroendocrine Tumor Patients.

Most well-differentiated neuroendocrine tumors (NETs) express high levels of somatostatin receptors, particularly subtypes 2 and 5. Somatostatin analogs (SSAs) bind to somatostatin receptors and are used for palliation of hormonal syndromes and control of tumor growth. The long-acting SSAs octreotide long-acting release and lanreotide are commonly used in the first-line metastatic setting because of their tolerable side effect profile. Radiolabeled SSAs are used both for imaging and for treatment of NETs. 177Lu-DOTATATE is a ß-emitting radiolabeled SSA that has been proven to significantly improve progression-free survival among patients with progressive midgut NETs and is approved for treatment of metastatic gastroenteropancreatic NETs. A key question in management of patients with gastroenteropancreatic and lung NETs is the sequencing of 177Lu-DOTATATE in relation to other systemic treatments (such as everolimus) or liver-directed therapies. This question is particularly complicated given the heterogeneity of NETs and the near absence of randomized trials comparing active treatment options. This state-of-the-art review examines the evidence supporting use of somatostatin-receptor-targeted treatments within the larger landscape of NET therapy and offers insights regarding optimal patient selection, assessment of benefit versus risk, and treatment sequencing.

Safety and Efficacy of Peptide Receptor Radionuclide Therapy (PRRT) Following Bland Embolization for Metastatic Neuroendocrine Tumors.

Rationale: Evaluating the long-term safety and efficacy of peptide receptor radionuclide therapy (PRRT) in patients with metastatic neuroendocrine tumors (mNETs) who have undergone prior bland hepatic transarterial embolization (TAE). Methods: Retrospective review of mNET patients who received PRRT with 177Lu-DOTATATE between 4/2018 and 02/2022 with and without prior TAE. The most recent clinical, imaging, and laboratory findings, including hepatic Common Terminology Criteria for Adverse Events v5.0, were compared to pre-PRRT. Results: 171 patients (95 M, 76 F, median age = 66) with mNET of different primary sites (9 foregut, 100 midgut, 9 hindgut, 44 pancreas, 9 unknown) received at least 1 cycle of PRRT with at least 6 months of follow-up, 110 of whom were embolization-naïve and 61 who had prior TAE. The median follow up was 22 months (range: 6-43). Patients with prior TAE had higher liver tumor burden on average than patients without prior TAE; however, the difference was not statistically significant (p = 0.06). There was no significant difference in the rates of G3 or G4 hepatotoxicity (p = 0.548 and p = 0.999, respectively) in patients who underwent prior TAE and those who were TAE-naïve. The hepatic progression-free survival was 22.9 months in TAE-naïve patients and 25.7, 20.2, and 12.8 months in patients with 1, 2, and 3 prior TAE treatments, respectively. Conclusion: Peptide receptor radionuclide therapy following transarterial bland embolization for mNET is safe and effective.

Hepatic Radioembolization: A Multistep Theragnostic Procedure.

This article provides a thorough overview of the practice and multistep approach of hepatic radioembolization. The current literature on hepatic radioembolization in primary or metastatic liver tumors as well as future perspectives are discussed.

Targeted radionuclide therapy in endocrine-related cancers: advances in the last decade.

Targeted radionuclide therapy plays an increasingly important role in managing endocrine-related tumors and significantly advances the therapeutic landscape for patients with these diseases. With increasing FDA-approved therapies and advances in the field, come an increased knowledge of the potential for long-term toxicities associated with these therapies and the field must develop new strategies to increase potency and efficacy while individualizing the selection of patients to those most likely to respond to treatment. Novel agents and modalities of therapy are also being explored. This review will discuss the current landscape and describe the avenues for growth in the field currently being explored.

Somatostatin Receptor Expression in Lung Neuroendocrine Tumors: An Analysis of DOTATATE PET Scans.

Somatostatin receptor (SSTR) expression in metastatic lung neuroendocrine tumors (NETs) has not been well characterized using PET imaging. Understanding the degree and uniformity of SSTR expression is important to establish the role of SSTR-targeted treatments in lung NETs. Methods: A retrospective institutional review of patients with metastatic lung NETs who underwent DOTATATE PET imaging from March 2017 to February 2023 was performed. Results: In total, 48 patients with metastatic lung NETs who underwent 68Ga- or 64Cu-DOTATATE PET imaging were identified. Four had completely negative SSTR expression, and 10 had very weak expression (less than in a normal liver). Among the remaining 34 patients, 21 had uniformly positive DOTATATE PET scans, and 13 had heterogeneous expression. Only 44% had uniformly positive receptor expression, identifying them as candidates for peptide receptor radionuclide therapy. Conclusion: Most metastatic lung NETs lack uniform SSTR expression and are thus suboptimal candidates for SSTR-targeted therapy. SSTR imaging in lung NETs should be evaluated carefully for uniformity of expression.

Expert Consensus Practice Recommendations of the North American Neuroendocrine Tumor Society for the management of high grade gastroenteropancreatic and gynecologic neuroendocrine neoplasms.

High-grade neuroendocrine neoplasms are a rare disease entity and account for approximately 10% of all neuroendocrine neoplasms. Because of their rarity, there is an overall lack of prospectively collected data available to advise practitioners as to how best to manage these patients. As a result, best practices are largely based on expert opinion. Recently, a distinction was made between well-differentiated high-grade (G3) neuroendocrine tumors and poorly differentiated neuroendocrine carcinomas, and with this, pathologic details, appropriate imaging practices and treatment have become more complex. In an effort to provide practitioners with the best guidance for the management of patients with high-grade neuroendocrine neoplasms of the gastrointestinal tract, pancreas, and gynecologic system, the North American Neuroendocrine Tumor Society convened a panel of experts to develop a set of recommendations and a treatment algorithm that may be used by practitioners for the care of these patients. Here, we provide consensus recommendations from the panel on pathology, imaging practices, management of localized disease, management of metastatic disease and surveillance and draw key distinctions as to the approach that should be utilized in patients with well-differentiated G3 neuroendocrine tumors vs poorly differentiated neuroendocrine carcinomas.

Developing a Patient-Reported Outcome Measure for Radionuclide Therapy for Prostate Cancer.

The field of radionuclide therapy (RNT) for prostate cancer (PC) is growing rapidly, with recent Food and Drug Administration approval of the first 177Lu-PSMA ligand. We aimed to develop the first patient-reported outcome (PRO) measure for PC patients receiving RNT. Methods: We identified relevant symptoms and toxicities by reviewing published trials and interviews with PC patients receiving RNT (n = 29), caregivers (n = 14), and clinicians (n = 11). Second, we selected items for measure inclusion. Third, we refined the item list with input from experts in RNTs and PROs. Fourth, we finalized the Functional Assessment of Cancer Therapy-Radionuclide Therapy (FACT-RNT) with patient input. Results: This multistep process yielded a brief 15-item measure deemed by key stakeholders to be relevant and useful in the context of RNT for PC. Conclusion: The FACT-RNT is a new standardized tool to monitor relevant symptoms and toxicities among PC patients in RNT trials and real-world settings.

Consensus report of the 2021 National Cancer Institute neuroendocrine tumor clinical trials planning meeting.

Important progress has been made over the last decade in the classification, imaging, and treatment of neuroendocrine neoplasm (NENs), with several new agents approved for use. Although the treatment options available for patients with well-differentiated neuroendocrine tumors (NETs) have greatly expanded, the rapidly changing landscape has presented several unanswered questions about how best to optimize, sequence, and individualize therapy. Perhaps the most important development over the last decade has been the approval of 177Lu-DOTATATE for treatment of gastroenteropancreatic-NETs, raising questions around optimal sequencing of peptide receptor radionuclide therapy (PRRT) relative to other therapeutic options, the role of re-treatment with PRRT, and whether PRRT can be further optimized through use of dosimetry among other approaches. The NET Task Force of the National Cancer Institute GI Steering Committee convened a clinical trial planning meeting in 2021 with multidisciplinary experts from academia, the federal government, industry, and patient advocates to develop NET clinical trials in the era of PRRT. Key clinical trial recommendations for development included 1) PRRT re-treatment, 2) PRRT and immunotherapy combinations, 3) PRRT and DNA damage repair inhibitor combinations, 4) treatment for liver-dominant disease, 5) treatment for PRRT-resistant disease, and 6) dosimetry-modified PRRT.