title: Computed Tomography-Guided Interstitial Brachytherapy for Locally Advanced Cervical Cancer: Introduction of the Technique and a Comparison of Dosimetry With Conventional Intracavitary Brachytherapy.
abstract: We present a new technique of 3-dimensional computed tomography-guided interstitial (IS) brachytherapy (BT) for locally advanced cervical cancer, offering a more advantageous clinical treatment approach.
  
  
  
  Interstitial BT was performed using an applicator combining uterine tandem and metal needles; needles were inserted freehand under real-time 3-dimensional computed tomography guidance. Twenty-eight patients with bulky tumors and/or parametrial extension (tumor size > 5 cm) after external beam radiotherapy received IS BT. Dosimetric outcomes of the IS BT including the total dose (external beam radiotherapy and high dose-rate BT) D90 for the high-risk clinical target volume (HR-CTV) and D2cc for the organs at risk (OARs) were investigated and compared with a former patient group consisting of 30 individuals who received the conventional intracavitary (IC) BT.
  
  
  
  The mean D90 values for HR-CTV in the IC BT and IS BT groups were 76.9 ± 5.7 and 88.1 ± 3.3 Gy, respectively. Moreover, 85.7% of the patients received D90 for HR-CTV of 87 Gy or greater in the IS BT group, and only 6.7% of the patients received D90 for HR-CTV of 87 Gy or greater in the IC BT group. The D2cc for the bladder, rectum, and sigmoid were 84.7 ± 6.8, 69.2 ± 4.2, and 67.8 ± 4.5 Gy in the IC BT group and 81.8 ± 6.5, 66.8 ± 4.0, and 64.8 ± 4.1 Gy in the IS BT group. The mean number of needles was 6.9 ± 1.4, with a mean depth of 2.9 ± 0.9 mm for each IS BT. Interstitial BT was associated with only minor complications.
  
  
  
  The IS BT technique resulted in better dose-volume histogram parameters for large volume tumors (>5 cm) compared with the conventional IC BT and acceptable risk of acute complications in locally advanced cervical cancer and is clinically feasible.
authors.affiliation: *Department of Radiation Oncology, The Second Affiliated Hospital of Jilin University; and †Cancer Center, The First Affiliated Hospital of Jilin University, Changchun, China.
authors.forename: Zhong-Shan
authors.initials: ZS
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.forename: Yang-Zhi
authors.initials: YZ
authors.lastname: Zhao
authors.forename: Xia
authors.initials: X
authors.lastname: Lin
authors.forename: Bing-Ya
authors.initials: BY
authors.lastname: Zhang
authors.forename: Chu
authors.initials: C
authors.lastname: Zhang
authors.forename: Hong-Yong
authors.initials: HY
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Yu
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Ren
authors.forename: Tie-Jun
authors.initials: TJ
authors.lastname: Wang
mesh_terms: D001918:Brachytherapy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000295:instrumentation / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*