Challenges in developing response evaluation criteria for peptide receptor radionuclide therapy: A consensus report from the European Neuroendocrine Tumor Society Advisory Board Meeting 2022 and the ENETS Theranostics Task Force.

Assessing the response to systemic therapy in neuroendocrine tumors (NET) is challenging since morphological imaging response is often delayed and not necessarily reflective of clinical benefit. Peptide receptor radionuclide therapy (PRRT) has a complex mechanism of action, further complicating response assessment. In response to these challenges, the European Neuroendocrine Tumor Society (ENETS) Theranostics Task Force conducted a statement-based survey among experts to identify the current landscape and unmet needs in PRRT response assessment.

Remission of longstanding metastatic paraganglioma in a patient after use of zoledronic acid.

A patient with a long history of bone predominant, metastatic paraganglioma who had multiple episodes of progressive disease despite prior treatments demonstrated a remarkable disease response to zoledronic acid. After 1 year of treatment, there was a complete resolution of lymphadenopathy and disappearance of all somatostatin receptor avid lesions by positron emission tomography-CT and radiopharmaceutical Gallium Ga 68 Dotatate. Stability of disease was further demonstrated by CT over several years.

Current and Future Perspectives of PDL1 PET and SPECT Imaging.

Programmed Death 1 (PD1) and Programmed Death Ligand (PDL1) play a crucial role in tumor microenvironment by helping cancer cells evade innate immunity. Numerous inhibitor anticancer drugs targeting this interplay have been used in clinical practice and many more are in preclinical stage. These drugs have shown promising results in achieving good response and long-term clinical benefit, is routinely performed to identify patients who may benefit.

Theranostics in Neuroendocrine Tumors: Updates and Emerging Technologies.

Advancements in somatostatin receptor (SSTR) targeted imaging and treatment of well-differentiated neuroendocrine tumors (NETs) have revolutionized the management of these tumors. This comprehensive review delves into the current practice, discussing the use of the various FDA-approved SSTR-agonist PET tracers and the predictive imaging biomarkers, and elaborating on Lu177-DOTATATE peptide receptor radionuclide therapy (PRRT) including the evolving areas of post-therapy imaging practices, PRRT retreatment, and the potential role of dosimetry in optimizing patient treatments. The future directions sections highlight ongoing research on investigational PET imaging radiotracers, future prospects in alpha particle therapy, and combination therapy strategies.

Quantitative Assessments of Tumor Activity in a General Oncologic PET/CT Population: Which Metric Minimizes Tracer Uptake Time Dependence?

In oncologic PET, the SUV and standardized uptake ratio (SUR) of a viable tumor generally increase during the postinjection period. In contrast, the net influx rate ( ), which is derived from dynamic PET data, should remain relatively constant. Uptake-time-corrected SUV (cSUV) and SUR (cSUR) have been proposed as uptake-time-independent, static alternatives to Our primary aim was to quantify the intrascan repeatability of , SUV, cSUV, SUR, and cSUR among malignant lesions on PET/CT.

Patlak Slope versus Standardized Uptake Value Image Quality in an Oncologic PET/CT Population: A Prospective Cross-Sectional Study.

Patlak slope (PS) images have the potential to improve lesion conspicuity compared with standardized uptake value (SUV) images but may be more artifact-prone. This study compared PS versus SUV image quality and hepatic tumor-to-background ratios (TBRs) at matched time points. Early and late SUV and PS images were reconstructed from dynamic positron emission tomography (PET) data.

Lu-Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer and Prior Ra (RALU Study).

Ra-dichloride (Ra) and Lu-prostate-specific membrane antigen (PSMA) are approved treatments for metastatic castration-resistant prostate cancer (mCRPC). The safety and effectiveness of sequential use of Ra and Lu-PSMA in patients with mCRPC are not well described. This study aimed to evaluate Lu-PSMA safety and efficacy in patients with mCRPC previously treated with Ra.

Case report: Peptide receptor radioligand therapy in metastatic pediatric neuroendocrine tumors.

Neuroendocrine tumors (NETs) are not commonly diagnosed in children. Metastatic NETs tend to have poor outcomes, and this is seen in adult and pediatric populations. The role of somatostatin receptor imaging using [Ga]Ga-DOTA-TATE for imaging and peptide receptor radionuclide therapy (PRRT) with [Lu]Lu-DOTA-TATE in children is currently not well established.

Optimization of Radiolabeling of a [Y]Y-Anti-CD66-Antibody for Radioimmunotherapy before Allogeneic Hematopoietic Cell Transplantation.

For patients with acute myeloid leukemia, myelodysplastic syndrome, or acute lymphoblastic leukemia, allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment. In addition to standard conditioning regimens for HCT, high-dose radioimmunotherapy (RIT) offers the unique opportunity to selectively deliver a high dose of radiation to the bone marrow while limiting side effects. Modification of a CD66b-specific monoclonal antibody (mAb) with a DTPA-based chelating agent should improve the absorbed dose distribution during therapy.

New horizon of radiopharmaceuticals in management of neuroendocrine tumors.

Neuroendocrine neoplasms are rare and heterogenous group of tumors with varying degrees of clinical presentations and involvement of multiple organ systems in the body. In the modern clinical practice somatostatin receptor molecular imaging and targeted radioligand therapy plays a vital role in the diagnosis and management of the disease. Several new and promising radiotracers for NET imaging and theranostics, belonging to various groups and classes are being studied and investigated.

Personalized [177Lu]Lutetium-PSMA Therapy for Patients with Pre-Treated Castration-Resistant Prostate Cancer: A Single Institution Experience from a Comprehensive Cancer Centre.

Castration resistant prostate cancer (CRPC) is characterized by an aggressive biological behavior with a relatively short survival time, especially in progressive tumors pretreated with new hormonal agents and taxane chemotherapy. [177Lu]-Lutetium-PSMA (Lu-PSMA) treatment has proven efficacy in these patients. However, around 30% of the CRPC patients do not benefit from Lu-PSMA treatment, and little is known about predictive factors for treatment success if Lu-PSMA is offered in an individualized approach based on clinical and laboratory features.

S2k Guideline - Merkel cell carcinoma (MCC, neuroendocrine carcinoma of the skin) - Update 2022.

Merkel cell carcinoma (MCC, ICD-O M8247/3) is a rare, malignant, primary skin tumor with epithelial and neuroendocrine differentiation. The tumor cells share many morphologic, immunohistochemical, and ultrastructural features with cutaneous Merkel cells. Nevertheless, the cell of origin of MCC is unclear.

Short-Interval, Low-Dose [ 177 Lu]Lu-Prostate-Specific Membrane Antigen in the Treatment of Refractory Glioblastoma.

Prostate-specific membrane antigen (PSMA) is expressed on the neovasculature as well as to some extent on the glioblastoma cells. With this background, we report the case of a 34-year-old man with recurrent glioblastoma who was treated with 2 cycles of low-dose [ 177 Lu]Lu-PSMA after exhausting all available treatment options in the state sector. Baseline imaging demonstrated intense PSMA signal in the known lesion, which was amenable to therapy.

Predictive and prognostic potential of pretreatment Ga-PSMA PET tumor heterogeneity index in patients with metastatic castration-resistant prostate cancer treated with 177Lu-PSMA.

Introduction: This study was conducted to evaluate the predictive values of volumetric parameters and radiomic features (RFs) extracted from pretreatment 68Ga-PSMA PET and baseline clinical parameters in response to 177Lu-PSMA therapy.

Materials And Methods: In this retrospective multicenter study, mCRPC patients undergoing 177Lu-PSMA therapy were enrolled. According to the outcome of therapy, the patients were classified into two groups including positive biochemical response (BCR) (≥ 50% reduction in the serum PSA value) and negative BCR (< 50%).

Safety and Survival Outcomes of Lu-Prostate-Specific Membrane Antigen Therapy in Patients with Metastatic Castration-Resistant Prostate Cancer with Prior Ra treatment: The RALU Study.

The radium lutetium (RALU) study evaluated the feasibility of sequential α- and β-emitter use in patients with bone-predominant metastatic castration-resistant prostate cancer. This preplanned interim retrospective analysis investigated safety and survival outcomes with Lu-PSMA in patients treated with prior Ra. Forty-nine patients were evaluated.

203 Pb-VMT-α-NET Scintigraphy of a Patient With Neuroendocrine Tumor.

In an end-stage midgut neuroendocrine tumor patient with carcinoid heart disease, right ventricular dysfunction, mildly reduced renal function, and refractory to 6 cycles of 177 Lu-HA-DOTATATE therapy, planar, and 22 hours SPECT/CT images were acquired after injection of 224 MBq of 203 Pb-VMT-α-NET to assess the feasibility of performing 212 Pb-VMT-α-NET therapy. A comparison of the 1.5 and 22 hours SPECT/CT images with 68 Ga-HA-DOTATATE PET/CT showed high uptake of 203 Pb-VMT-α-NET in liver metastases matching with the results of the PET/CT investigation.

SARS-CoV-2 vaccination site as possible pitfall on somatostatin receptor imaging.

SARS-CoV-2 (COVID-19) vaccination numbers are globally increasing. Therefore, an increased chance exists that patients undergoing Peptide Receptor Radionuclide Therapy (PRRT) or diagnostic radionuclide imaging for Neuroendocrine Tumours (NETs) may have recently received vaccination. We report the imaging findings of two NETs patients, A-following [Lu] Lu-DOTATATE PRRT post therapy planar scintigraphy and single photon emission computed tomography with computed tomography (SPECT/CT), and B-following [ Ga]Ga-DOTA-NOC positron emission tomography with computed tomography (PET/CT) respectively.