Go Akamatsu1, Yasuhiko Ikari2, Hiroyuki Nishida2, Tomoyuki Nishio2, Akihito Ohnishi2, Akira Maebatake3, Masayuki Sasaki3, Michio Senda4. 1. Division of Molecular Imaging, Institute of Biomedical Research and Innovation, Kobe, Japan; and Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. 2. Division of Molecular Imaging, Institute of Biomedical Research and Innovation, Kobe, Japan; and. 3. Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. 4. Division of Molecular Imaging, Institute of Biomedical Research and Innovation, Kobe, Japan; and senda@fbri.org.
Abstract
UNLABELLED: Standardized uptake values (SUVs) have been widely used in the diagnosis of malignant tumors and in clinical trials of tumor therapies as semiquantitative metrics of tumor (18)F-FDG uptake. However, SUVs for small lesions are liable to errors due to partial-volume effect and statistical noise. The purpose of this study was to evaluate the reproducibility and accuracy of maximum and peak SUV (SUVmax and SUVpeak, respectively) of small lesions in phantom experiments. METHODS: We used a body phantom with 6 spheres in a quarter warm background. The PET data were acquired for 1,800 s in list-mode, from which data were extracted to generate 15 PET images for each of the 60-, 90-, 120-, 150-, and 180-s scanning times. The SUVmax and SUVpeak of the hot spheres in the 1,800-s scan were used as a reference (SUVref,max and SUVref,peak). Coefficients of variation for both SUVmax and SUVpeak in hot spheres (CVmax and CVpeak) were calculated to evaluate the variability of the SUVs. On the other hand, percentage differences between SUVmax and SUVref,max and between SUVpeak and SUVref,peak were calculated for evaluation of the accuracy of SUV. We additionally examined the coefficients of variation of background activity and the percentage background variability as parameters for the physical assessment of image quality. RESULTS: Visibility of a 10-mm-diameter hot sphere was considerably different among scan frames. The CVmax and CVpeak increased as the sphere size became smaller and as the acquisition time became shorter. SUVmax was generally overestimated as the scan time shortened and the sphere size increased. The SUVmax and SUVpeak of a 37-mm-diameter sphere for 60-s scans had average positive biases of 28.3% and 4.4%, compared with the reference. CONCLUSION: SUVmax was variable and overestimated as the scan time decreased and the sphere size increased. In contrast, SUVpeak was a more robust and accurate metric than SUVmax. The measurements of SUVpeak (or SUVpeak normalized to lean body mass) in addition to SUVmax are desirable for reproducible and accurate quantification in clinical situations.
UNLABELLED: Standardized uptake values (SUVs) have been widely used in the diagnosis of malignant tumors and in clinical trials of tumor therapies as semiquantitative metrics of tumor (18)F-FDG uptake. However, SUVs for small lesions are liable to errors due to partial-volume effect and statistical noise. The purpose of this study was to evaluate the reproducibility and accuracy of maximum and peak SUV (SUVmax and SUVpeak, respectively) of small lesions in phantom experiments. METHODS: We used a body phantom with 6 spheres in a quarter warm background. The PET data were acquired for 1,800 s in list-mode, from which data were extracted to generate 15 PET images for each of the 60-, 90-, 120-, 150-, and 180-s scanning times. The SUVmax and SUVpeak of the hot spheres in the 1,800-s scan were used as a reference (SUVref,max and SUVref,peak). Coefficients of variation for both SUVmax and SUVpeak in hot spheres (CVmax and CVpeak) were calculated to evaluate the variability of the SUVs. On the other hand, percentage differences between SUVmax and SUVref,max and between SUVpeak and SUVref,peak were calculated for evaluation of the accuracy of SUV. We additionally examined the coefficients of variation of background activity and the percentage background variability as parameters for the physical assessment of image quality. RESULTS: Visibility of a 10-mm-diameter hot sphere was considerably different among scan frames. The CVmax and CVpeak increased as the sphere size became smaller and as the acquisition time became shorter. SUVmax was generally overestimated as the scan time shortened and the sphere size increased. The SUVmax and SUVpeak of a 37-mm-diameter sphere for 60-s scans had average positive biases of 28.3% and 4.4%, compared with the reference. CONCLUSION: SUVmax was variable and overestimated as the scan time decreased and the sphere size increased. In contrast, SUVpeak was a more robust and accurate metric than SUVmax. The measurements of SUVpeak (or SUVpeak normalized to lean body mass) in addition to SUVmax are desirable for reproducible and accurate quantification in clinical situations.
Authors: Georgia Keramida; Alexander Dunford; Guven Kaya; Constantinos D Anagnostopoulos; Adrien Michael Peters Journal: Am J Nucl Med Mol Imaging Date: 2018-06-05
Authors: Benjamin Noto; Florian Büther; Katharina Auf der Springe; Nemanja Avramovic; Walter Heindel; Michael Schäfers; Thomas Allkemper; Lars Stegger Journal: EJNMMI Res Date: 2017-02-06 Impact factor: 3.138
Authors: Daniëlle Koopman; Jorn A van Dalen; Hester Arkies; Ad H J Oostdijk; Anne Brecht Francken; Jos Bart; Cornelis H Slump; Siert Knollema; Pieter L Jager Journal: EJNMMI Res Date: 2018-01-16 Impact factor: 3.138