{"title":"68Ga和18F的小靶标可重复性:靶标浓度和成像时间对临床相关幻影中SUV测量的影响","authors":"Michael S Silosky, Luke W Patten, Bennett B Chin","doi":"","DOIUrl":null,"url":null,"abstract":"<p><p>Quantification of tumor uptake using PET imaging is important for the evaluation of therapy response. For <sup>18</sup>F FDG PET scans, a change in uptake of 25% is commonly considered significant. For scans using novel radiopharmaceuticals, the threshold of significance is unclear. Factors including imaging time, tumor size, activity concentration, and radiopharmaceutical may affect the repeatablity of uptake metrics. This work evaluates the effect of these parameters on the repeatablity of maximum SUV (SUV<sub>max</sub>) and mean SUV (SUV<sub>mean</sub>) in phantoms using <sup>18</sup>F and <sup>68</sup>Ga. An Esser PET phantom (Data Spectrum, Durham NC) was scanned on a Biograph Horizon PET/CT scanner (Siemens Medical Solutions, Malvern PA) using <sup>18</sup>F and <sup>68</sup>Ga. Data were acquired for 5 minutes with reconstructions between 0.5-5 minutes. The background activity mimicked clinical scans with target-to-background (T/B) ratios from 1.7-19.8. The SUV<sub>max</sub> and SUV<sub>mean</sub> were measured for 5 slices. The mean, standard deviation, and coefficient of variation (COV) were calculated. The effects of radionuclide, imaging time, activity concentration, and target size on COV were evaluated using multivariate gamma regressions. COV for <sup>68</sup>Ga was 40% higher and 54% higher on average than for <sup>18</sup>F for SUV<sub>max</sub> and SUV<sub>mean</sub>, respectively. Decreased lesion size, imaging time, and activity concentration were significantly associated with increased COV for both metrics (P < 0.001). COV was substantially reduced at high T/B for <sup>68</sup>Ga. At the highest T/B the COV for SUV<sub>max</sub> and SUV<sub>mean</sub> was within the typical range seen for <sup>18</sup>F. COV is relatively high for small targets (8 mm) but is dramatically reduced with high radiotracer uptake.</p>","PeriodicalId":7572,"journal":{"name":"American journal of nuclear medicine and molecular imaging","volume":null,"pages":null},"PeriodicalIF":2.0000,"publicationDate":"2021-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8414403/pdf/ajnmmi0011-0280.pdf","citationCount":"0","resultStr":"{\"title\":\"Small target repeatability of <sup>68</sup>Ga and <sup>18</sup>F: effects of target concentration and imaging time on SUV measurements in clinically relevant phantoms.\",\"authors\":\"Michael S Silosky, Luke W Patten, Bennett B Chin\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Quantification of tumor uptake using PET imaging is important for the evaluation of therapy response. For <sup>18</sup>F FDG PET scans, a change in uptake of 25% is commonly considered significant. For scans using novel radiopharmaceuticals, the threshold of significance is unclear. Factors including imaging time, tumor size, activity concentration, and radiopharmaceutical may affect the repeatablity of uptake metrics. This work evaluates the effect of these parameters on the repeatablity of maximum SUV (SUV<sub>max</sub>) and mean SUV (SUV<sub>mean</sub>) in phantoms using <sup>18</sup>F and <sup>68</sup>Ga. An Esser PET phantom (Data Spectrum, Durham NC) was scanned on a Biograph Horizon PET/CT scanner (Siemens Medical Solutions, Malvern PA) using <sup>18</sup>F and <sup>68</sup>Ga. Data were acquired for 5 minutes with reconstructions between 0.5-5 minutes. The background activity mimicked clinical scans with target-to-background (T/B) ratios from 1.7-19.8. The SUV<sub>max</sub> and SUV<sub>mean</sub> were measured for 5 slices. The mean, standard deviation, and coefficient of variation (COV) were calculated. The effects of radionuclide, imaging time, activity concentration, and target size on COV were evaluated using multivariate gamma regressions. COV for <sup>68</sup>Ga was 40% higher and 54% higher on average than for <sup>18</sup>F for SUV<sub>max</sub> and SUV<sub>mean</sub>, respectively. Decreased lesion size, imaging time, and activity concentration were significantly associated with increased COV for both metrics (P < 0.001). COV was substantially reduced at high T/B for <sup>68</sup>Ga. At the highest T/B the COV for SUV<sub>max</sub> and SUV<sub>mean</sub> was within the typical range seen for <sup>18</sup>F. COV is relatively high for small targets (8 mm) but is dramatically reduced with high radiotracer uptake.</p>\",\"PeriodicalId\":7572,\"journal\":{\"name\":\"American journal of nuclear medicine and molecular imaging\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.0000,\"publicationDate\":\"2021-08-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8414403/pdf/ajnmmi0011-0280.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"American journal of nuclear medicine and molecular imaging\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2021/1/1 0:00:00\",\"PubModel\":\"eCollection\",\"JCR\":\"Q3\",\"JCRName\":\"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"American journal of nuclear medicine and molecular imaging","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/1/1 0:00:00","PubModel":"eCollection","JCR":"Q3","JCRName":"RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING","Score":null,"Total":0}
Small target repeatability of 68Ga and 18F: effects of target concentration and imaging time on SUV measurements in clinically relevant phantoms.
Quantification of tumor uptake using PET imaging is important for the evaluation of therapy response. For 18F FDG PET scans, a change in uptake of 25% is commonly considered significant. For scans using novel radiopharmaceuticals, the threshold of significance is unclear. Factors including imaging time, tumor size, activity concentration, and radiopharmaceutical may affect the repeatablity of uptake metrics. This work evaluates the effect of these parameters on the repeatablity of maximum SUV (SUVmax) and mean SUV (SUVmean) in phantoms using 18F and 68Ga. An Esser PET phantom (Data Spectrum, Durham NC) was scanned on a Biograph Horizon PET/CT scanner (Siemens Medical Solutions, Malvern PA) using 18F and 68Ga. Data were acquired for 5 minutes with reconstructions between 0.5-5 minutes. The background activity mimicked clinical scans with target-to-background (T/B) ratios from 1.7-19.8. The SUVmax and SUVmean were measured for 5 slices. The mean, standard deviation, and coefficient of variation (COV) were calculated. The effects of radionuclide, imaging time, activity concentration, and target size on COV were evaluated using multivariate gamma regressions. COV for 68Ga was 40% higher and 54% higher on average than for 18F for SUVmax and SUVmean, respectively. Decreased lesion size, imaging time, and activity concentration were significantly associated with increased COV for both metrics (P < 0.001). COV was substantially reduced at high T/B for 68Ga. At the highest T/B the COV for SUVmax and SUVmean was within the typical range seen for 18F. COV is relatively high for small targets (8 mm) but is dramatically reduced with high radiotracer uptake.
期刊介绍:
The scope of AJNMMI encompasses all areas of molecular imaging, including but not limited to: positron emission tomography (PET), single-photon emission computed tomography (SPECT), molecular magnetic resonance imaging, magnetic resonance spectroscopy, optical bioluminescence, optical fluorescence, targeted ultrasound, photoacoustic imaging, etc. AJNMMI welcomes original and review articles on both clinical investigation and preclinical research. Occasionally, special topic issues, short communications, editorials, and invited perspectives will also be published. Manuscripts, including figures and tables, must be original and not under consideration by another journal.