PET/CT 검사 시 체중과 체표면적에 따른 SUV의 상관관계

Correlation of SUV According to the Body Weight and Body Surface Area in PET/CT Imaging

Purpose: There are several methods of measuring SUV in PET/CT imaging including SUVbw which uses the body weight, SUVbsa which that uses body surface area and SUVlbm which uses lean body mass. Currently, Seoul National University Hospital uses SUVbw method which minimizes the variability. In this study, we compared and analyzed the correlation between SUVbw and SUVbsa according to patients' body mass index. Materials and Methods: Using Biograph mCT40 (Siemens, Germany), we conducted ¹⁸F-FDG PET/CT imaging on 70 patients (41 males, 29 females; ages 58.04±12.44). We classified the patients as underweight (BMI<20), normal weight (20≦BMI<25), overweight (25≦BMI<30), obese (30≦BMI<35) and severely obese (35≦BMI) according to the patient's sex, age and BIM. Then, bone, liver and lungs were set as ROI for calculation of maximum values of SUVbw and SUVbsa, through Syngo.via VA11A analysis program. Results: Comparing the five groups divided according to the BMI by the standard differences between SUVbw to SUVbsa, SUVmax was measured to be 0.66±0.15, 0.78±0.35, 0.77±0.21, 1.00±0.44, 1.53±0.38 for bones in underweight, normal weight, overweight, obese and severely obese groups, respectively. For liver, values of SUVmax were 1.64±0.16, 2.06±0.34, 2.19±0.21, 2.52±0.21 and 2.74±0.40 in the same order. And for lung, values of SUVmax were 0.69±0.33, 0.54±0.17, 0.62±0.23, 0.83±0.29, 1.03±0.30. Conclusion: By comparing and analyzing the differences between SUVbw and SUVbsa in this study, it was found that the differences between SUVbw and SUVbsa increased as patient's BMI increased. Thus, there is room for error in the values of SUV depending on the methods of calculations, and appropriate methods must be applied according to the circumstances in clinical settings.