Non-[F]FDG PET-Radiopharmaceuticals in Oncology.

Molecular imaging is a growing field, driven by technological advances, such as the improvement of PET-CT scanners through the introduction of digital detectors and scanners with an extended field of view, resulting in much higher sensitivity and a variety of new specific radiopharmaceuticals that allow the visualization of specific molecular pathways and even theragnostic approaches. In oncology, the development of dedicated tracers is crucial for personalized therapeutic approaches. Novel peptides allow the visualization of many different targets, such as PD-1 and PD-L1 expression, chemokine expression, HER expression, T-cell imaging, microenvironmental imaging, such as FAP imaging, and many more.

Radiomics and Artificial Intelligence Landscape for [F]FDG PET/CT in Multiple Myeloma.

[F]FDG PET/CT is a powerful imaging modality of high performance in multiple myeloma (MM) and is considered the appropriate method for assessing treatment response in this disease. On the other hand, due to the heterogeneous and sometimes complex patterns of bone marrow infiltration in MM, the interpretation of PET/CT can be particularly challenging, hampering interobserver reproducibility and limiting the diagnostic and prognostic ability of the modality. Although many approaches have been developed to address the issue of standardization, none can yet be considered a standard method for interpretation or objective quantification of PET/CT.

Enhancing the diagnostic capacity of [F]PSMA-1007 PET/MRI in primary prostate cancer staging with artificial intelligence and semi-quantitative DCE: an exploratory study.

Background: To investigate the ability of artificial intelligence (AI)-based and semi-quantitative dynamic contrast enhanced (DCE) multiparametric MRI (mpMRI), performed within [F]-PSMA-1007 PET/MRI, in differentiating benign from malignant prostate tissues in patients with primary prostate cancer (PC).

Results: A total of seven patients underwent whole-body [F]-PSMA-1007 PET/MRI examinations including a pelvic mpMRI protocol with T2w, diffusion weighted imaging (DWI) and DCE image series. Conventional analysis included visual reading of PET/MRI images and Prostate Imaging Reporting & Data System (PI-RADS) scoring of the prostate.

Impact of different parametric Patlak imaging approaches and comparison with a 2-tissue compartment pharmacokinetic model with a long axial field-of-view (LAFOV) PET/CT in oncological patients.

Aim: The recently introduced Long-Axial-Field-of-View (LAFOV) PET-CT scanners allow for the first-time whole-body dynamic- and parametric imaging. Primary aim of this study was the comparison of direct and indirect Patlak imaging as well as the comparison of different time frames for Patlak calculation with the LAFOV PET-CT in oncological patients. Secondary aims of the study were lesion detectability and comparison of Patlak analysis with a two-tissue-compartment model (2TCM).

Total Body PET-CT Protocols in Oncology.

Recently developed long axial field of view (LAFOV) PET-CT scanners, including total body scanners, are already in use in a few centers worldwide. These systems have some major advantages over standard axial field of view (SAFOV) PET-CT scanners, mainly due to up to 20 times higher sensitivity and therefore improved lesion detectability. Other advantages are the reduction of the PET acquisition time for a static whole-body measurement, the reduction of the administered radiotracer dose, and the ability to perform delayed scans with good image quality, which is important for imaging radionuclides with long half-lives and pharmaceuticals with long biodistribution times, such as Zr-labeled antibodies.

Long Axial Field-of-View (LAFOV) PET/CT in Prostate Cancer.

PSMA-targeted PET/CT is currently considered the most effective non-invasive diagnostic technique for imaging PSMA-positive lesions in prostate cancer (PC), and its introduction has significantly enhanced the role of nuclear medicine in both the diagnosis and therapy (theranostics) of this oncological entity. In line with developments in radiopharmaceuticals, significant progress has been made in the development of PET/CT systems. In particular, the advent of long axial field-of-view (LAFOV) PET/CT scanners has represented a major leap forward in molecular imaging, with early results from clinical applications of these systems showing significant improvements over previous standard axial field-of-view systems in terms of sensitivity, image quality and lesion quantification, while enabling whole-body dynamic PET imaging.

Diagnostic Potential of Supplemental Static and Dynamic Ga-FAPI-46 PET for Primary F-FDG-Negative Pulmonary Lesions.

PET using Ga-labeled fibroblast activation protein (FAP) inhibitors (FAPIs) holds high potential for diagnostic imaging of various malignancies, including lung cancer (LC). However, F-FDG PET is still the clinical gold standard for LC imaging. Several subtypes of LC, especially lepidic LC, are frequently F-FDG PET-negative, which markedly hampers the assessment of single pulmonary lesions suggestive of LC.

Artificial intelligence-based, volumetric assessment of the bone marrow metabolic activity in [F]FDG PET/CT predicts survival in multiple myeloma.

Purpose: Multiple myeloma (MM) is a highly heterogeneous disease with wide variations in patient outcome. [F]FDG PET/CT can provide prognostic information in MM, but it is hampered by issues regarding standardization of scan interpretation. Our group has recently demonstrated the feasibility of automated, volumetric assessment of bone marrow (BM) metabolic activity on PET/CT using a novel artificial intelligence (AI)-based tool.

Combined whole-body dynamic and static PET/CT with low-dose [F]PSMA-1007 in prostate cancer patients.

Aim: In addition to significant improvements in sensitivity and image quality, the recent introduction of long axial field-of-view (LAFOV) PET/CT scanners has enabled dynamic whole-body imaging for the first time. We aim herein to determine an appropriate acquisition time range for static low-dose [F]PSMA-1007 PET imaging and to investigate the whole-body pharmacokinetics of [F]PSMA-1007 by dynamic PET with the LAFOV Biograph Vision Quadra PET/CT in a group of prostate cancer patients.

Methodology: In total, 38 prostate cancer patients were enrolled in the analysis for staging or re-staging purposes.

Immunohistochemical FAP Expression Reflects Ga-FAPI PET Imaging Properties of Low- and High-Grade Intraductal Papillary Mucinous Neoplasms and Pancreatic Ductal Adenocarcinoma.

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) are grossly visible (typically > 5 mm) intraductal epithelial neoplasms of mucin-producing cells, arising in the main pancreatic duct or its branches. According to the current 2-tiered grading scheme, these lesions are categorized as having either low-grade (LG) dysplasia, which has a benign prognosis, or high-grade (HG) dysplasia, which formally represents a carcinoma in situ and thus can transform to pancreatic ductal adenocarcinoma (PDAC). Because both entities require different treatments according to their risk of becoming malignant, a precise pretherapeutic diagnostic differentiation is inevitable for adequate patient management.

The Theranostic Optimization of PSMA-GCK01 Does Not Compromise the Imaging Characteristics of [Tc]Tc-PSMA-GCK01 Compared to Dedicated Diagnostic [Tc]Tc-EDDA/HYNIC-iPSMA in Prostate Cancer.

Purpose: Radiolabeled PSMA-ligands play a major role in today's nuclear medicine. Since approval of [Lu]Lu-PSMA-617 for therapy of metastatic prostate cancer, availability of Lu became bottleneck of supply due to the high demand. Recently, a theranostic PSMA-ligand, PSMA-GCK01, was developed which can be labeled either diagnostically with Tc or therapeutically with Re with both nuclides available from well-known generator systems.

Comparison of early and late Ga-FAPI-46-PET in 33 patients with possible recurrence of pancreatic ductal adenocarcinomas.

Positron emission tomography with Gallium (Ga) labeled inhibitors of fibroblast activation protein (Ga-FAPI-PET) is a promising imaging technique for patients with recurrent pancreatic ductal adenocarcinomas (PDAC). To date, it is not clear if different acquisition timepoints for Ga-FAPI-PET may result in comparable imaging information and if repetitive Ga-FAPI-PET imaging may add diagnostic value to single timepoint acquisition for recurrent PDAC. Here we analyzed retrospectively early (20 min p.

Impact of Ga-FAPI PET/CT on Staging and Oncologic Management in a Cohort of 226 Patients with Various Cancers.

Since the development of fibroblast activation protein-targeted radiopharmaceuticals, Ga-fibroblast activation protein inhibitor (FAPI) PET/CT has been found to be suitable for detecting primary and metastatic lesions in many types of tumors. However, there is currently a lack of reliable data regarding the clinical impact of this family of probes. To address this gap, the present study aimed to analyze the clinical impact of Ga-FAPI PET/CT by examining a large cohort of patients with various tumors.

Application of an artificial intelligence-based tool in [F]FDG PET/CT for the assessment of bone marrow involvement in multiple myeloma.

Purpose: [F]FDG PET/CT is an imaging modality of high performance in multiple myeloma (MM). Nevertheless, the inter-observer reproducibility in PET/CT scan interpretation may be hampered by the different patterns of bone marrow (BM) infiltration in the disease. Although many approaches have been recently developed to address the issue of standardization, none can yet be considered a standard method in the interpretation of PET/CT.

The prognostic value of [F]FDG PET/CT based response monitoring in metastatic melanoma patients undergoing immunotherapy: comparison of different metabolic criteria.

Purpose: To investigate the prognostic value of [F]FDG PET/CT as part of response monitoring in metastatic melanoma patients treated with immune checkpoint inhibitors (ICIs).

Methods: Sixty-seven patients underwent [F]FDG PET/CT before start of treatment (baseline PET/CT), after two cycles (interim PET/CT) and after four cycles of ICIs administration (late PET/CT). Metabolic response evaluation was based on the conventional EORTC and PERCIST criteria, as well as the newly introduced, immunotherapy-modified PERCIMT, imPERCIST5 and iPERCIST criteria.

Long axial field of view (LAFOV) PET-CT: implementation in static and dynamic oncological studies.

Long axial field of view (LAFOV) PET-CT scanners have been recently developed and are already in clinical use in few centers worldwide. Although still limited, the hitherto acquired experience with these novel systems highlights an increased sensitivity as their main advantage, which results in an increased lesion detectability. This attribute, alternatively, allows a reduction in PET acquisition time and/or administered radiotracer dose, while it renders delayed scanning of satisfying diagnostic accuracy possible.

Positron Emission Tomography-Based Immunoimaging for Cancer Patient Stratification: Toward a More Holistic Approach.

Immunotherapy with immune checkpoint inhibitors (ICIs) changed the treatment management in several solid metastatic tumors with very poor prognosis, in particular in melanoma stage IV since its introduction in 2011. However, it is not yet fully understood why some patients respond to ICIs and others not, and it is also unclear why melanomas are the most sensitive tumors to ICI treatment. Selection criteria for patient stratification are needed and several approaches are under evaluation.