Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma
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The Ohio State University / OhioLINK
2013
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ndltd-OhioLink-oai-etd.ohiolink.edu-osu13643087242021-08-03T05:21:10Z Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma McMurray, Alexis Kelly Medical Imaging Health Sciences Biology Comparative Osteosarcoma animal model stereology lung metastasis micro-computed tomography positron emission tomography <b>Introduction/Purpose:</b> Osteosarcoma (OSA) is a common cancer of dogs comprising approximately 80 to 85% of all canine skeletal tumors (6% of all canine tumors), and is also the 8th most common childhood cancer. Detection of pulmonary metastasis as early as possible is vital, since the presence of and progression or regression of pulmonary metastasis critically impacts prognosis and treatment. Thus pulmonary metastatic load is a method of determining treatment response in patients with osteosarcoma. An objective in vivo method for measuring the efficacy of treatments in preclinical models of OSA is currently lacking, with most studies involving euthanasia of mice at different time points to track the effect of treatment via histopathology. This strategy requires large numbers of mice and precludes the assessment of individual treatment response. Our purpose was to determine whether micro-computed tomography in conjunction with micro-positron emission tomography (µCT/PET) is more sensitive for the detection of pulmonary metastasis than µCT alone and whether active pulmonary metastatic load could be quantified using µPET.<b>Methods:</b> Twelve mice had canine OSA cells injected into their right tibias. Mice were imaged at 3 and 5 weeks post- injection. The µCT and µCT/PET combined images were evaluated for pulmonary metastasis at each time point and the results compared. Regions of interest (ROI) were drawn around the lungs on each µCT slice to create a volume of interest (VOI) for measurement of 18F-fluorodeoxyglucose (18F-FDG) uptake. The VOIs were applied to the corresponding co-registered µPET images. The standard uptake value (SUV) for the lungs was divided by the corresponding liver SUV. The SUV ratios were compared between time points for each mouse, and between mice within a given time point. Mice were euthanized after imaging at 5 weeks and histopathology and stereologic analysis were performed on paraffin-embedded sections of the lungs.<b>Results:</b> µCT images were reviewed for evidence of pulmonary metastasis with and without the assistance of co-registered µPET images. Nine of twelve (75%) mice had metastasis at 3 weeks and 10/12 (83%) mice had metastasis 5 weeks post-injection. µPET and µCT findings were concordant for 70% of the nodules. In 15% of cases, µPET scans identified a nodule that was initially evident on µCT and in 10% of cases PET indicated a nodule that was never seen on µCT. In 5% of cases with nodules identified on µCT there was no corresponding18F-FDG uptake. A statistical difference was not found between the 2 time points (paired t test p= 0.075). The SUV ratio values at 5 weeks post tibial injection (second imaging session) did not correlate to histologic metastatic load. <b>Discussions/Conclusion:</b> µCT/PET was helpful in detecting pulmonary nodules before they were evident on µCT, and confirming those nodules that were suspected or not initially detected on µCT. However, in the mouse model of OSA metastasis, µPET does not offer a reliable means of quantifying metastatic load. Possible reasons for this include respiratory motion, variable uptake between the two time points, and necrosis of tumor or overlap of signal from other nearby anatomic structures. 2013-08-09 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1364308724 http://rave.ohiolink.edu/etdc/view?acc_num=osu1364308724 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws. |
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NDLTD |
| language |
English |
| sources |
NDLTD |
| topic |
Medical Imaging Health Sciences Biology Comparative Osteosarcoma animal model stereology lung metastasis micro-computed tomography positron emission tomography |
| spellingShingle |
Medical Imaging Health Sciences Biology Comparative Osteosarcoma animal model stereology lung metastasis micro-computed tomography positron emission tomography McMurray, Alexis Kelly Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| author |
McMurray, Alexis Kelly |
| author_facet |
McMurray, Alexis Kelly |
| author_sort |
McMurray, Alexis Kelly |
| title |
Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| title_short |
Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| title_full |
Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| title_fullStr |
Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| title_full_unstemmed |
Micro-CT/PET Assessment of Lung Metastasis in a Mouse Model of Osteosarcoma |
| title_sort |
micro-ct/pet assessment of lung metastasis in a mouse model of osteosarcoma |
| publisher |
The Ohio State University / OhioLINK |
| publishDate |
2013 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=osu1364308724 |
| work_keys_str_mv |
AT mcmurrayalexiskelly microctpetassessmentoflungmetastasisinamousemodelofosteosarcoma |
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1719418775389863936 |