title: Intra-patient Variability of FDG Standardized Uptake Values in Mediastinal Blood Pool, Liver, and Myocardium during R-CHOP Chemotherapy in Patients with Diffuse Large B-cell Lymphoma.
abstract: OBJECTIVE
  18F-fluorodeoxyglucose (FDG) PET/CT is useful for staging and evaluating treatment response in patients with diffuse large B-cell lymphoma (DLBCL). A five-point scale model using the mediastinal blood pool (MBP) and liver as references is a recommended method for interpreting treatment response. We evaluated the variability in standardized uptake values (SUVs) of the MBP, liver, and myocardium during chemotherapy in patients with DLBCL.
  
  
  METHODS
  We analyzed 60 patients with DLBCL who received rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) treatment and underwent baseline, interim, and final FDG PET/CT scans. The FDG uptakes of lymphoma lesions, MBP, liver, and myocardium were assessed, and changes in the MBP and liver SUV and possible associated factors were evaluated.
  
  
  RESULTS
  The SUV of the liver did not change significantly during the chemotherapy. However, the SUVmeanof MBP showed a significant change though the difference was small (p = 0.019). SUVmeanof MBP and liver at baseline and interim scans was significantly lower in patients with advanced Ann Arbor stage on diagnosis. The SUVmeanof the MBP and liver was negatively correlated with the volumetric index of lymphoma lesions in baseline scans (r = -0.547, p < 0.001; r = -0.502, p < 0.001). Positive myocardial FDG uptake was more frequently observed in interim and final scans than in the baseline scan, but there was no significant association between the MBP and liver uptake and myocardial uptake.
  
  
  CONCLUSIONS
  The SUV of the liver was not significantly changed during R-CHOP chemotherapy in patients with DLBCL, whereas the MBP SUV of the interim scan decreased slightly. However, the SUV of the reference organs may be affected by tumor burden, and this should be considered when assessing follow-up scans. Although myocardial FDG uptake was more frequently observed after R-CHOP chemotherapy, it did not affect the SUV of the MBP and liver.
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Soo Jeong
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Hyun Kyung
authors.initials: HK
authors.lastname: Yi
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Chae Hong
authors.initials: CH
authors.lastname: Lim
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Young Seok
authors.initials: YS
authors.lastname: Cho
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Yearn Seong
authors.initials: YS
authors.lastname: Choe
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Byung-Tae
authors.initials: BT
authors.lastname: Kim
authors.affiliation: Departments of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul Republic of Korea.
authors.forename: Seung Hwan
authors.identifier: 0000-0003-4302-1920
authors.initials: SH
authors.lastname: Moon
keywords: Diffuse large B-cell lymphoma; FDG; Liver; Mediastinum; Myocardium; PET