TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Weich, Alexander
A1  - Higuchi, Takahiro
A1  - Schmid, Jan S.
A1  - Schirbel, Andreas
A1  - Lassmann, Michael
A1  - Wild, Vanessa
A1  - Rudelius, Martina
A1  - Kudlich, Theodor
A1  - Herrmann, Ken
A1  - Scheurlen, Michael
A1  - Buck, Andreas K.
A1  - Kropf, Saskia
A1  - Wester, Hans-Jürgen
A1  - Lapa, Constantin
T1  - Imaging of Chemokine Receptor 4 Expression in Neuroendocrine Tumors - a Triple Tracer Comparative Approach
JF  - Theranostics
N2  - C-X-C motif chemokine receptor 4 (CXCR4) and somatostatin receptors (SSTR) are overexpressed in gastro-entero-pancreatic neuroendocrine tumors (GEP-NET). In this study, we aimed to elucidate the feasibility of non-invasive CXCR4 positron emission tomography/computed tomography (PET/CT) imaging in GEP-NET patients using [\(^{68}\)Ga]Pentixafor in comparison to \(^{68}\)Ga-DOTA-D-Phe-Tyr3-octreotide ([\(^{68}\)Ga]DOTATOC) and \(^{18}\)F-fluorodeoxyglucose ([\(^{18}\)F]FDG). Twelve patients with histologically proven GEP-NET (3xG1, 4xG2, 5xG3) underwent [\(^{68}\)Ga]DOTATOC, [\(^{18}\)F]FDG, and [\(^{68}\)Ga]Pentixafor PET/CT for staging and planning of the therapeutic management. Scans were analyzed on a patient as well as on a lesion basis and compared to immunohistochemical staining patterns of CXCR4 and somatostatin receptors SSTR2a and SSTR5. [\(^{68}\)Ga]Pentixafor visualized tumor lesions in 6/12 subjects, whereas [\(^{18}\)F]FDG revealed sites of disease in 10/12 and [\(^{68}\)Ga]DOTATOC in 11/12 patients, respectively. Regarding sensitivity, SSTR-directed PET was the superior imaging modality in all G1 and G2 NET. CXCR4-directed PET was negative in all G1 NET. In contrast, 50% of G2 and 80% of G3 patients exhibited [\(^{68}\)Ga]Pentixafor-positive tumor lesions. Whereas CXCR4 seems to play only a limited role in detecting well-differentiated NET, increasing receptor expression could be non-invasively observed with increasing tumor grade. Thus, [\(^{68}\)Ga]Pentixafor PET/CT might serve as non-invasive read-out for evaluating the possibility of CXCR4-directed endoradiotherapy in advanced dedifferentiated SSTR-negative tumors.
KW  - SSTR
KW  - peptide receptor radionuclide therapy
KW  - neuroendocrine tumor
KW  - [\(^{68}\)Ga]Pentixafor
KW  - CXCR4
KW  - chemokine receptor
KW  - PET/CT
KW  - DOTATOC
KW  - PRRT
KW  - Positronen-Emissions-Tomografie
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158008
VL  - 7
IS  - 6
ER  - 
TY  - JOUR
A1  - Werner, Rudolf A.
A1  - Weich, Alexander
A1  - Kircher, Malte
A1  - Solnes, Lilja B.
A1  - Javadi, Mehrbod S.
A1  - Higuchi, Takahiro
A1  - Buck, Andreas K.
A1  - Pomper, Martin G.
A1  - Rowe, Steven
A1  - Lapa, Constantin
T1  - The theranostic promise for neuroendocrine tumors in the late 2010s – Where do we stand, where do we go?
JF  - Theranostics
N2  - More than 25 years after the first peptide receptor radionuclide therapy (PRRT), the concept of somatostatin receptor (SSTR)-directed imaging and therapy for neuroendocrine tumors (NET) is seeing rapidly increasing use. To maximize the full potential of its theranostic promise, efforts in recent years have expanded recommendations in current guidelines and included the evaluation of novel theranostic radiotracers for imaging and treatment of NET. Moreover, the introduction of standardized reporting framework systems may harmonize PET reading, address pitfalls in interpreting SSTR-PET/CT scans and guide the treating physician in selecting PRRT candidates. Notably, the concept of PRRT has also been applied beyond oncology, e.g. for treatment of inflammatory conditions like sarcoidosis. Future perspectives may include the efficacy evaluation of PRRT compared to other common treatment options for NET, novel strategies for closer monitoring of potential side effects, the introduction of novel radiotracers with beneficial pharmacodynamic and kinetic properties or the use of supervised machine learning approaches for outcome prediction. This article reviews how the SSTR-directed theranostic concept is currently applied and also reflects on recent developments that hold promise for the future of theranostics in this context.
KW  - theranostics
KW  - Positronen-Emissions-Tomografie
KW  - PRRT
KW  - somatostatin receptor
KW  - peptide receptor radionuclide therapy
KW  - neuroendocrine tumor
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170264
VL  - 8
IS  - 22
ER  -