title: Estimating Lymphodynamic Conditions and Lymphovenous Anastomosis Efficacy Using (99m)Tc-phytate Lymphoscintigraphy with SPECT-CT in Patients with Lower-limb Lymphedema.
abstract: BACKGROUND
  Diagnostic and therapeutic strategies for lower-limb lymphedema have not yet been established. The purpose of this study was to estimate the lymphodynamic condition and therapeutic efficacy of lymphovenous anastomosis (LVA) in lower-limb lymphedema patients using 2-phase (99m)Tc-phytate lymphoscintigraphy with single-photon emission computed tomography-computed tomography (SPECT-CT).
  
  
  METHODS
  In this study, consecutive patients with lower-limb lymphedema who underwent 2-phase lymphoscintigraphy using (99m)Tc-phytate were enrolled between June 2013 and June 2014. SPECT-CT was also performed to clarify the relationships between functional and morphological information. In both the early and delayed images, inguinal lymph node accumulation, dermal backflow, and their sequential alternations were evaluated, and liver-to-blood ratio and inguinal lymph node-to-blood ratio were calculated. All participants were classified into 6 types of lymphodynamic conditions based on the image findings. Patients with both dermal backflow and associated normal lymphatic vessel accumulation proceeded to LVA and underwent a second lymphoscintigraphy after the operation.
  
  
  RESULTS
  Of all 30 participants, the largest population was categorized as type 4, which had consistent inguinal lymph node accumulation defect with dermal backflow. In 12 operated cases, dermal backflow was degraded in 10 cases by LVA. Liver-to-blood ratio in both early and delayed images and inguinal lymph node-to-blood ratio in delayed image significantly increased after LVA.
  
  
  CONCLUSIONS
  Lymphoscintigraphy with SPECT-CT can provide both functional and morphological information simultaneously in patients with lower-limb lymphedema. Using these procedures, a type categorization for the patients was devised, which reflects their lymphodynamic conditions. The therapeutic efficacy of LVA could also be estimated quantitatively by the derived findings.
authors.affiliation: Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan; and Department of Clinical Radiology, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iimura
authors.affiliation: Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan; and Department of Clinical Radiology, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Fukushima
authors.affiliation: Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan; and Department of Clinical Radiology, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kumita
authors.affiliation: Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan; and Department of Clinical Radiology, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Rei
authors.initials: R
authors.lastname: Ogawa
authors.affiliation: Department of Plastic, Reconstructive and Regenerative Surgery, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan; and Department of Clinical Radiology, Nippon Medical School, Graduate School of Medicine, Tokyo, Japan.
authors.forename: Hiko
authors.initials: H
authors.lastname: Hyakusoku