@article{LassmannPreylowskiSchloegletal.2013, author = {Lassmann, Michael and Preylowski, Veronika and Schl{\"o}gl, Susanne and Schoenahl, Fr{\´e}d{\´e}ric and J{\"o}rg, Gerhard and Samnick, Samuel and Buck, Andreas K.}, title = {Is the Image Quality of I-124-PET Impaired by an Automatic Correction of Prompt Gammas?}, series = {PLoS ONE}, journal = {PLoS ONE}, doi = {10.1371/journal.pone.0071729}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96863}, year = {2013}, abstract = {Objectives The aim of this study is to evaluate the quality of I-124 PET images with and without prompt gamma compensation (PGC) by comparing the recovery coefficients (RC), the signal to noise ratios (SNR) and the contrast to F-18 and Ga-68. Furthermore, the influence of the PGC on the quantification and image quality is evaluated. Methods For measuring the image quality the NEMA NU2-2001 PET/SPECT-Phantom was used containing 6 spheres with a diameter between 10 mm and 37 mm placed in water with different levels of background activity. Each sphere was filled with the same activity concentration measured by an independently cross-calibrated dose calibrator. The "hot" sources were acquired with a full 3D PET/CT (Biograph mCT®, Siemens Medical USA). Acquisition times were 2 min for F-18 and Ga-68, and 10 min for I-124. For reconstruction an OSEM algorithm was applied. For I-124 the images were reconstructed with and without PGC. For the calculation of the RCs the activity concentrations in each sphere were determined; in addition, the influence of the background correction was studied. Results The RCs of Ga-68 are the smallest (79\%). I-124 reaches similar RCs (87\% with PGC, 84\% without PGC) as F-18 (84\%). showing that the quantification of I-124 images is similar to F-18 and slightly better than Ga-68. With background activity the contrast of the I-124 PGC images is similar to Ga-68 and F-18 scans. There was lower background activity in the I-124 images without PGC, which probably originates from an overcorrection of the scatter contribution. Consequently, the contrast without PGC was much higher than with PGC. As a consequence PGC should be used for I-124. Conclusions For I-124 there is only a slight influence on the quantification depending on the use of the PGC. However, there are considerable differences with respect to I-124 image quality.}, language = {en} } @article{WesterKellerSchotteliusetal.2015, author = {Wester, Hans J{\"u}rgen and Keller, Ulrich and Schottelius, Margret and Beer, Ambros and Philipp-Abbrederis, Kathrin and Hoffmann, Frauke and Šimeček, Jakub and Gerngross, Carlos and Lassmann, Michael and Herrmann, Ken and Pellegata, Natalia and Rudelius, Martina and Kessler, Horst and Schwaiger, Markus}, title = {Disclosing the CXCR4 expression in lymphoproliferative diseases by targeted molecular imaging}, series = {Theranostics}, volume = {5}, journal = {Theranostics}, number = {6}, doi = {10.7150/thno.11251}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-144537}, pages = {618-630}, year = {2015}, abstract = {Chemokine ligand-receptor interactions play a pivotal role in cell attraction and cellular trafficking, both in normal tissue homeostasis and in disease. In cancer, chemokine receptor-4 (CXCR4) expression is an adverse prognostic factor. Early clinical studies suggest that targeting CXCR4 with suitable high-affinity antagonists might be a novel means for therapy. In addition to the preclinical evaluation of [\(^{68}\)Ga]Pentixafor in mice bearing human lymphoma xenografts as an exemplary CXCR4-expressing tumor entity, we report on the first clinical applications of [\(^{68}\)Ga]Pentixafor-Positron Emission Tomography as a powerful method for CXCR4 imaging in cancer patients. [\(^{68}\)Ga]Pentixafor binds with high affinity and selectivity to human CXCR4 and exhibits a favorable dosimetry. [\(^{68}\)Ga]Pentixafor-PET provides images with excellent specificity and contrast. This non-invasive imaging technology for quantitative assessment of CXCR4 expression allows to further elucidate the role of CXCR4/CXCL12 ligand interaction in the pathogenesis and treatment of cancer, cardiovascular diseases and autoimmune and inflammatory disorders.}, language = {en} }