ISRN Molecular Imaging The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Subcutaneous Administration of D-Luciferin is an Effective Alternative to Intraperitoneal Injection in Bioluminescence Imaging of Xenograft Tumors in Nude Mice Wed, 18 Dec 2013 17:35:21 +0000 Currently, intraperitoneal (IP) injection of D-luciferin is the preferred method of providing substrate for bioluminescence imaging (BLI); however it has a failure rate of 3–10% due to accidental intestinal injection. The present study evaluates the quality of BLI after subcutaneous (SC) injection of D-luciferin and demonstrates the effectiveness of SC injection in anatomically disparate tumor models. Mice bearing luciferase-expressing tumors underwent BLI after SC or IP injection of D-luciferin. The average time to maximal luminescence was 6 min (range 5–9 min) after SC injection and 8 min (range 5–8 min) after IP injection. Within 7 minutes of injection, SC and IP routes yielded similar luminescence in subcutaneous, intracranial, tongue, and lung xenograft tumor models. In a model of combined subcutaneous and intracranial xenografts, SC injection resulted in proportional luminescence at all sites, confirming that preferential delivery of substrate does not occur. While tumors were occasionally not visualized with IP injection, all tumors were visualized reliably with SC injection. Thus, SC injection of D-luciferin is a convenient and effective alternative to IP injection for BLI in nude mice. It may be a preferable approach, particularly for tumors with weaker signals and/or when greater precision is required. Ashraf A. Khalil, Mark J. Jameson, William C. Broaddus, Theodore D. Chung, Sarah E. Golding, Seth M. Dever, Elisabeth Rosenberg, and Kristoffer Valerie Copyright © 2013 Ashraf A. Khalil et al. All rights reserved. Dosimetry and Therapeutic Ratios for Rhenium-186 HEDP Thu, 11 Apr 2013 10:11:08 +0000 Rhenium-186 (Re-186) is a β-emitting radionuclide. Emitted β-particles have ranges up to 4.5 mm in tissue, capable of delivering high doses to skeletal regions of high Re-186 concentrations while sparing adjacent radiosensitive regions and thus making the irradiation well tolerated for the patient. Along with the β-emissions, γ-rays are emitted having an adequate energy for imaging during therapy and biodistribution assessment for patient-specific dosimetry calculations. The relatively short physical half-life combined with the β-emissions allows the delivery of relatively high activity rate for a short period of time in areas of concentration. This study is a short review concerning the palliative treatment of skeletal metastases using 186Re-HEDP. After presenting the dominant ways of 186Re production, special emphasis is given to dosimetry issues while the effect of palliation therapy can be evaluated through the comparison of the absorbed dose in metastatic lesion relatively to the normal bone region. Accurate dose estimation is required taking into account the anatomic individual difference of each patient. For this purpose a patient specific dosimetric model considering metastatic lesions as spherical nodules is introduced. In order to quantify in a representative way the results of palliation treatment, the concept of therapeutic ratios is analyzed. Maria Argyrou, Alexia Valassi, Maria Andreou, and Maria Lyra Copyright © 2013 Maria Argyrou et al. All rights reserved. 18F-fluoro-L-thymidine Positron Emission Tomography for Mucosal Head and Neck Squamous Cell Carcinoma Treated with Definitive Chemoradiation: A Pilot Study of Nodal Assessment and Tracer Safety Sat, 16 Mar 2013 15:00:40 +0000 We aim to assess the utility and safety of 18F-fluoro-L-thymidine- positron emission tomography (FLT-PET), in reference to 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET) in the assessment of nodal involvement for mucosal head and neck SCC (HNSCC). Methods. Ten patients with HNSCC receiving definitive chemoradiation (CRT) were enrolled. Baseline FLT-PET and FDG-PET were obtained. The total number of involved lymph nodes and ultimate nodal staging by the baseline FDG-PET and FLT-PET was compared. Receiver Operating Characteristics (ROC) analysis for the matched nodes was performed to identify an optimal maximal standardized uptake value (SUVmax) cutpoint. Results. The tracer uptake by the involved nodes on FDG-PET was higher than those judged to be involved by FLT-PET (mean SUVmax: 5.9 versus 3.4; ). More abnormal lymph nodes were detected by FLT-PET than FDG-PET (Odds ratio = 3.67; ). The optimal SUVmax cutpoint for FLT-PET to correspond with positive FDG-PET for the matched lymph nodes was 3.25 (range 3.1–3.4). Conclusions. It is unlikely that FLT-PET will be a more accurate staging investigation than FDG-PET. A SUVmax of 3.25 may be considered as a reference cut-off in determining if a cervical lymph node is involved for HNSCC. Validation in a surgical cohort with pathological correlation is warranted. Charles Lin, Aravind Ravi Kumar, Jacqui Keller, Peter O’Rourke, David McFarlane, Raymond Gwynne, Lizbeth Kenny, Nicole Buddle, Jarad Martin, Brett Hughes, and Paul Thomas Copyright © 2013 Charles Lin et al. All rights reserved. Ga-68- and Cu-64-Labeled NOTA-Albumin Conjugates for PET Sentinel Lymph Node Imaging Mon, 18 Feb 2013 16:52:34 +0000 Our objective was to develop and evaluate Ga-68- and Cu-64-labeled albumin conjugates for PET imaging of sentinel lymph nodes. Four different albumin conjugates were prepared starting from NOTA-HSA. The lymph node uptake of Ga-68- and Cu-64-labeled albumin conjugates was investigated after subcutaneous injection into the foot pad of Wistar rats. A pig model was utilized for further biological evaluation of the lymph node uptake. For all the four conjugates, radiolabeling with Ga-68 and Cu-64 resulted in >95% radiochemical yield. Denatured and mannosylated Ga-68 NOTA-HSA revealed the highest popliteal lymph node uptake in rats (% ID and % ID 10 min and 60 min p.i., resp.). The popliteal lymph node reached its maximum activity after approximately 120 min and remained constant for denatured and mannosylated Cu-64 NOTA-HSA at least up to 240 min p.i. In a pig model, 2% of the injected dose of this compound was found in the sentinel lymph node 60 min after subcutaneous injection. In conclusion, PET imaging of sentinel lymph nodes with Ga-68- and Cu-64-labeled denatured NOTA-Man-HSA could be successfully demonstrated and deserves further investigations. Eik Schiller, Ralf Bergmann, Gerd Wunderlich, Michael Andreeff, Anita Jacob, and Hans-Jürgen Pietzsch Copyright © 2013 Eik Schiller et al. All rights reserved.