TY - JOUR A1 - Werner, Rudolf A1 - Schmid, Jan-Stefan A1 - Higuchi, Takahiro A1 - Javadi, Mehrbod S. A1 - Rowe, Steven P. A1 - Märkl, Bruno A1 - Aulmann, Christoph A1 - Fassnacht, Martin A1 - Kroiß, Matthias A1 - Reiners, Christoph A1 - Buck, Andreas A1 - Kreissl, Michael A1 - Lapa, Constantin T1 - Predictive value of \(^{18}\)F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib JF - Journal of Nuclear Medicine N2 - Introduction: Therapeutic options in advanced medullary thyroid carcinoma (MTC) have markedly improved since the introduction of tyrosine kinase inhibitors (TKI). We aimed to assess the role of metabolic imaging using 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) positron emission tomography/computed tomography (PET/CT) shortly before and 3 months after initiation of TKI treatment. Methods: Eighteen patients with advanced and progressive MTC scheduled for vandetanib treatment underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after TKI treatment initiation. During follow-up, CT scans were performed every 3 months and analyzed according to Response Evaluation Criteria In Solid Tumors (RECIST). The predictive value for estimating progression-free (PFS) and overall survival (OS) was examined by investigating \(^{18}\)F-FDG mean/maximum standardized uptake values (SUVmean/max) of the metabolically most active lesion as well as by analyzing clinical parameters (tumor marker doubling times {calcitonin, carcinoembryonic antigen (CEA)}, prior therapies, RET (rearranged during transfection) mutational status, and disease type). Results: Within a median follow-up of 5.2 years, 9 patients experienced disease progression after a median time interval of 2.1y whereas the remainder had ongoing disease control (n=5 partial response and n=4 stable disease). Eight of the 9 patients with progressive disease died from MTC after a median of 3.5y after TKI initiation. Pre-therapeutic SUVmean >4.0 predicted a significantly shorter PFS (PFS: 1.9y vs. 5.2y; p=0.04). Furthermore, sustained high 18F-FDG uptake at 3 months with a SUVmean>2.8 tended to portend an unfavorable prognosis with a PFS of 1.9y (vs. 3.5y; p=0.3). Prolonged CEA doubling times were significantly correlated with longer PFS (r=0.7) and OS (r=0.76, p<0.01, respectively). None of the other clinical parameters had prognostic significance. Conclusions: Pre-therapeutic \(^{18}\)F-FDG PET/CT holds prognostic information in patients with advanced MTC scheduled for treatment with the TKI vandetanib. Low tumor metabolism of SUVmean < 4.0 prior to treatment predicts longer progression-free survival. KW - positron emission tomography KW - Medullärer Schilddrüsenkrebs KW - Positronen-Emissions-Tomografie KW - medullary thyroid carcinoma KW - tyrosine kinase inhibitor KW - vandetanib KW - 2- deoxy-2-(18F)fluoro-D-glucose KW - 18F-FDG Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-161256 SN - 0161-5505 N1 - This research was originally published in JNM. Rudolf A. Werner, Jan-Stefan Schmid, Takahiro Higuchi, Mehrbod S. Javadi, Steven P. Rowe, Bruno Märkl, Christoph Aulmann, Martin Fassnacht, Matthias Kroiss, Christoph Reiners, Andreas K. Buck, Michael C. Kreissl, Constantin Lapa. Predictive value of 18F-FDG PET in patients with advanced medullary thyroid carcinoma treated with vandetanib. J Nucl Med. May 1, 2018;vol. 59 no. 5: 756-761. © SNMMI. ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Chen, Xinyu A1 - Rowe, Steven P. A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro T1 - Moving into the Next Era of PET Myocardial Perfusion Imaging - Introduction of Novel \(^{18}\)F-labeled Tracers JF - The International Journal of Cardiovascular Imaging N2 - The heart failure (HF) epidemic continues to rise with coronary artery disease (CAD) as one of its main causes. Novel concepts for risk stratification to guide the referring cardiologist towards revascularization procedures are of significant value. Myocardial perfusion imaging (MPI) using single-photon emission computed tomography (SPECT) agents has demonstrated high accuracy for the detection of clinically relevant stenoses. With positron emission tomography (PET) becoming more widely available, mainly due to its diagnostic performance in oncology, perfusion imaging with that modality is more practical than in the past and overcomes existing limitations of SPECT MPI. Advantages of PET include more reliable quantification of absolute myocardial blood flow, the routine use of computed tomography for attenuation correction, a higher spatiotemporal resolution and a higher count sensitivity. Current PET radiotracers such as rubidium-82 (half-life, 76 sec), oxygen-15 water (2 min) or nitrogen-13 ammonia (10 min) are labeled with radionuclides with very short half-lives, necessitating that stress imaging is performed under pharmacological vasodilator stress instead of exercise testing. However, with the introduction of novel 18F-labeled MPI PET radiotracers (half-life, 110 min), the intrinsic advantages of PET can be combined with exercise testing. Additional advantages of those radiotracers include, but are not limited to: potentially improved cost-effectiveness due to the use of pre-existing delivery systems and superior imaging qualities, mainly due to the shortest positron range among available PET MPI probes. In the present review, widely used PET MPI radiotracers will be reviewed and potential novel 18F-labeled perfusion radiotracers will be discussed. KW - heart failure with mid-range ejection fraction KW - Positronenemissionstomografie KW - coronary artery disease KW - precision medicine KW - positron emission tomography KW - PET KW - SPECT KW - myocardial perfusion imaging KW - MPI KW - 18F-flurpiridaz KW - 18FFBnTP KW - HFmrEF Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-169134 SN - 1569-5794 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Bundschuh, Ralph A. A1 - Bundschuh, Lena A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro A1 - Weich, Alexander A1 - Sheikhbahaei, Sara A1 - Pienta, Kenneth J. A1 - Buck, Andreas K. A1 - Pomper, Martin G. A1 - Gorin, Michael A. A1 - Lapa, Constantin A1 - Rowe, Steven P. T1 - MI-RADS: Molecular Imaging Reporting and Data Systems – A Generalizable Framework for Targeted Radiotracers with Theranostic Implications JF - Annals of Nuclear Medicine N2 - Both prostate-specific membrane antigen (PSMA)- and somatostatin receptor (SSTR)-targeted positron emission tomography (PET) imaging agents for staging and restaging of prostate carcinoma or neuroendocrine tumors, respectively, are seeing rapidly expanding use. In addition to diagnostic applications, both classes of radiotracers can be used to triage patients for theranostic endoradiotherapy. While interpreting PSMA- or SSTR-targeted PET/computed tomography (CT) scans, the reader has to be aware of certain pitfalls. Adding to the complexity of the interpretation of those imaging agents, both normal biodistribution, and also false-positive and -negative findings differ between PSMA- and SSTR-targeted PET radiotracers. Herein summarized under the umbrella term molecular imaging reporting and data systems (MI-RADS), two novel RADS classifications for PSMA- and SSTR-targeted PET imaging are described (PSMA- and SSTR-RADS). Both framework systems may contribute to increase the level of a reader’s confidence and to navigate the imaging interpreter through indeterminate lesions, so that appropriate workup for equivocal findings can be pursued. Notably, PSMA- and SSTR-RADS are structured in a reciprocal fashion, i.e. if the reader is familiar with one system, the other system can readily be applied as well. In the present review we will discuss the most common pitfalls on PSMA- and SSTR-targeted PET/CT, briefly introduce PSMA- and SSTR-RADS, and define a future role of the umbrella framework MI-RADS compared to other harmonization systems. KW - PET KW - Positronen-Emissions-Tomografie KW - prostate cancer KW - neuroendocrine tumor KW - prostate-specific membrane antigen (PSMA) KW - somatostatin receptor (SSTR) KW - positron emission tomography KW - theranostics KW - standardization KW - RADS KW - reporting and data systems KW - personalized medicine Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166995 SN - 0914-7187 ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Bundschuh, Ralph A. A1 - Higuchi, Takahiro A1 - Javadi, Mehrbod S. A1 - Rowe, Steven P. A1 - Zsótér, Norbert A1 - Kroiss, Matthias A1 - Fassnacht, Martin A1 - Buck, Andreas K. A1 - Kreissl, Michael C. A1 - Lapa, Constantin T1 - Volumetric and Texture Analysis of Pretherapeutic \(^{18}\)F-FDG PET can Predict Overall Survival in Medullary Thyroid Cancer Patients Treated with Vandetanib JF - Endocrine N2 - Purpose: The metabolically most active lesion in 2-deoxy-2-(\(^{18}\)F)fluoro-D-glucose (\(^{18}\)F-FDG) PET/CT can predict progression-free survival (PFS) in patients with medullary thyroid carcinoma (MTC) starting treatment with the tyrosine kinase inhibitor (TKI) vandetanib. However, this metric failed in overall survival (OS) prediction. In the present proof of concept study, we aimed to explore the prognostic value of intratumoral textural features (TF) as well as volumetric parameters (total lesion glycolysis, TLG) derived by pre-therapeutic \(^{18}\)F-FDG PET. Methods: Eighteen patients with progressive MTC underwent baseline \(^{18}\)F-FDG PET/CT prior to and 3 months after vandetanib initiation. By manual segmentation of the tumor burden at baseline and follow-up PET, intratumoral TF and TLG were computed. The ability of TLG, imaging-based TF, and clinical parameters (including age, tumor marker doubling times, prior therapies and RET (rearranged during transfection) mutational status) for prediction of both PFS and OS were evaluated. Results: The TF Complexity and the volumetric parameter TLG obtained at baseline prior to TKI initiation successfully differentiated between low- and high-risk patients. Complexity allocated 10/18 patients to the high-risk group with an OS of 3.3y (vs. low-risk group, OS=5.3y, 8/18, AUC=0.78, P=0.03). Baseline TLG designated 11/18 patients to the high-risk group (OS=3.5y vs. low-risk group, OS=5y, 7/18, AUC=0.83, P=0.005). The Hazard Ratio for cancer-related death was 6.1 for Complexity (TLG, 9.5). Among investigated clinical parameters, the age at initiation of TKI treatment reached significance for PFS prediction (P=0.02, OS, n.s.). Conclusions: The TF Complexity and the volumetric parameter TLG are both independent parameters for OS prediction. KW - personalized medicine KW - Positronen-Emissions-Tomografie KW - medullary thyroid carcinoma KW - tyrosine kinase inhibitor KW - TKI KW - vandetanib KW - 18F-FDG KW - positron emission tomography KW - 2-deoxy-2-(18F)fluoro-D-glucose KW - PET Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-167910 SN - 1355-008X ER - TY - JOUR A1 - Werner, Rudolf A. A1 - Chen, Xinyu A1 - Hirano, Mitsuru A1 - Rowe, Steven P. A1 - Lapa, Constantin A1 - Javadi, Mehrbod S. A1 - Higuchi, Takahiro T1 - SPECT vs. PET in Cardiac Innervation Imaging: Clash of the Titans JF - Clinical and Translational Imaging N2 - Purpose: We aim to provide an overview of the conventional single photon emission computed tomography (SPECT) and emerging positron emission tomography (PET) catecholamine analogue tracers for assessing myocardial nerve integrity, in particular focusing on \(^{18}\)F-labeled tracers. Results: Increasingly, the cardiac sympathetic nervous system (SNS) is being studied by non-invasive molecular imaging approaches. Forming the backbone of myocardial SNS imaging, the norepinephrine (NE) transporter at the sympathetic nerve terminal plays a crucial role for visualizing denervated myocardium: in particular, the single-photon-emitting NE analogue \(^{123}\)I-meta-Iodobenzylguanidine (\(^{123}\)I-mIBG) has demonstrated favorable results in the identification of patients at a high risk for cardiac death. However, cardiac neuronal PET agents offer several advantages inlcuding improved spatio-temporal resolution and intrinsic quantifiability. Compared to their \(^{11}\)C-labeled counterparts with a short half-life (20.4 min), novel \(^{18}\)F-labeled PET imaging agents to assess myocardial nerve integrity have the potential to revolutionize the field of SNS molecular imaging: The longer half-life of \(^{18}\)F (109.8 min) allows for more flexibility in the study design and delivery from central cyclotron facilities to smaller hospitals may lead to further cost reduction. A great deal of progress has been made by the first in-human studies of such \(^{18}\)F-labeled SNS imaging agents. Moreover, dedicated animal platforms open avenues for further insights into the handling of radiolabeled catecholamine analogues at the sympathetic nerve terminal. Conclusions: \(^{18}\)F-labeled imaging agents demonstrate key properties for mapping cardiac sympathetic nerve integrity and might outperform current SPECT-based or \(^{11}\)C-labeled tracers in the long run. KW - single photon emission computed tomography: sympathetic nerve KW - Positronen-Emissions-Tomografie KW - 18F-LMI1195 KW - 11C-hydroxyephedrine KW - 123I-metaiodobenzylguanidine KW - positron emission tomography Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-163628 SN - 2281-5872 ER - TY - JOUR A1 - Khatri, Wajahat A1 - Chung, Hyun Woo A1 - Werner, Rudolf A. A1 - Leal, Jeffrey P. A1 - Pienta, Kenneth J. A1 - Lodge, Martin A. A1 - Gorin, Michael A. A1 - Pomper, Martin G. A1 - Rowe, Steven P. T1 - Effect of point-spread function reconstruction for indeterminate PSMA-RADS-3A lesions on PSMA-targeted PET imaging of men with prostate cancer JF - Diagnostics N2 - Purpose: Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) is emerging as an important modality for imaging patients with prostate cancer (PCa). As with any imaging modality, indeterminate findings will arise. The PSMA reporting and data system (PSMA-RADS) version 1.0 codifies indeterminate soft tissue findings with the PSMA-RADS-3A moniker. We investigated the role of point-spread function (PSF) reconstructions on categorization of PSMA-RADS-3A lesions. Methods: This was a post hoc analysis of an institutional review board approved prospective trial. Around 60 min after the administration of 333 MBq (9 mCi) of PSMA-targeted \(^{18}\)F-DCFPyL, patients underwent PET/computed tomography (CT) acquisitions from the mid-thighs to the skull vertex. The PET data were reconstructed with and without PSF. Scans were categorized according to PSMA-RADS version 1.0, and all PSMA-RADS-3A lesions on non-PSF images were re-evaluated to determine if any could be re-categorized as PSMA-RADS-4. The maximum standardized uptake values (SUVs) of the lesions, mean SUVs of blood pool, and the ratios of those values were determined. Results: A total of 171 PSMA-RADS-3A lesions were identified in 30 patients for whom both PSF reconstructions and cross-sectional imaging follow-up were available. A total of 13/171 (7.6%) were re-categorized as PSMA-RADS-4 lesions with PSF reconstructions. A total of 112/171 (65.5%) were found on follow-up to be true positive for PCa, with all 13 of the re-categorized lesions being true positive on follow-up. The lesions that were re-categorized trended towards having higher SUV\(_{max}\)-lesion and SUV\(_{max}\)-lesion/SUV\(_{mean}\)-blood-pool metrics, although these relationships were not statistically significant. Conclusions: The use of PSF reconstructions for \(^{18}\)F-DCFPyL PET can allow the appropriate re-categorization of a small number of indeterminate PSMA-RADS-3A soft tissue lesions as more definitive PSMA-RADS-4 lesions. The routine use of PSF reconstructions for PSMA-targeted PET may be of value at those sites that utilize this technology. KW - prostate-specific membrane antigen KW - reporting and data system KW - positron emission tomography Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236528 SN - 2075-4418 VL - 11 IS - 4 ER - TY - JOUR A1 - Toyama, Yoshitaka A1 - Werner, Rudolf A. A1 - Ruiz-Bedoya, Camilo A. A1 - Ordonez, Alvaro A. A1 - Takase, Kei A1 - Lapa, Constantin A1 - Jain, Sanjay K. A1 - Pomper, Martin G. A1 - Rowe, Steven P. A1 - Higuchi, Takahiro T1 - Current and future perspectives on functional molecular imaging in nephro-urology: theranostics on the horizon JF - Theranostics N2 - In recent years, a paradigm shift from single-photon-emitting radionuclide radiotracers toward positron-emission tomography (PET) radiotracers has occurred in nuclear oncology. Although PET-based molecular imaging of the kidneys is still in its infancy, such a trend has emerged in the field of functional renal radionuclide imaging. Potentially allowing for precise and thorough evaluation of renal radiotracer urodynamics, PET radionuclide imaging has numerous advantages including precise anatomical co-registration with CT images and dynamic three-dimensional imaging capability. In addition, relative to scintigraphic approaches, PET can allow for significantly reduced scan time enabling high-throughput in a busy PET practice and further reduces radiation exposure, which may have a clinical impact in pediatric populations. In recent years, multiple renal PET radiotracers labeled with C-11, Ga-68, and F-18 have been utilized in clinical studies. Beyond providing a precise non-invasive read-out of renal function, such radiotracers may also be used to assess renal inflammation. This manuscript will provide an overview of renal molecular PET imaging and will highlight the transformation of conventional scintigraphy of the kidneys toward novel, high-resolution PET imaging for assessing renal function. In addition, future applications will be introduced, e.g. by transferring the concept of molecular image-guided diagnostics and therapy (theranostics) to the field of nephrology. KW - glomerular filtration rate KW - renal KW - kidney KW - renal function KW - positron emission tomography KW - nephrology KW - urology KW - molecular imaging KW - theranostics Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-260090 VL - 11 IS - 12 ER -