title: Three-dimensional verification of ¹²⁵I seed stability after permanent implantation in the parotid gland and periparotid region.
abstract: OBJECTIVE
  To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data.
  
  
  METHODS
  Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive (125)I interstitial brachytherapy were retrospectively reviewed in this study. Serial CT data were obtained during follow-up. Mimics and Geomagic Studio software were used for seed reconstruction and stability analysis, respectively.
  
  
  RESULTS
  Seed loss and/or migration outside of the treated area were absent in all patients during follow-up (23-71 months). Total seed cluster volume was maximized on day 1 post-implantation due to edema and decreased significantly by an average of 13.5 % (SD = 9.80 %; 95 % CI, 6.82-17.68 %) during the first two months and an average of 4.5 % (SD = 3.60 %; 95 % CI, 2.29-6.29 %) during the next four months. Volume stabilized over the subsequent six months.
  
  
  CONCLUSIONS
  (125)I seed number and location were stable with a general volumetric shrinkage tendency in the parotid gland and periparotid region. Three-dimensional seed reconstruction of CT images is feasible for visualization and verification of implanted seeds in parotid brachytherapy.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China. bubblebomb@sina.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Fan
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China. hmwd97@126.com.
authors.forename: Ming-Wei
authors.initials: MW
authors.lastname: Huang
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China. Zhenglei2bh@163.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Zheng
authors.affiliation: Center of Digital Dentistry, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China. kqcadcs@bjmu.edu.cn.
authors.forename: Yi-Jiao
authors.initials: YJ
authors.lastname: Zhao
authors.affiliation: Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology, Beijing, China. rszhang@126.com.
authors.forename: Jian-Guo
authors.initials: JG
authors.lastname: Zhang
mesh_terms: D000328:Adult; D001918:Brachytherapy / Q000379:methods*; D002277:Carcinoma / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D010306:Parotid Gland / Q000000981:diagnostic imaging; D010307:Parotid Neoplasms / Q000532:radiotherapy*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D007457:Iodine Radioisotopes