title: Clinical feasibility of interstitial brachytherapy using a "hybrid" applicator combining uterine tandem and interstitial metal needles based on CT for locally advanced cervical cancer.
abstract: To explore the dosimetric advantage of target volume and surrounding normal tissue by using interstitial (IS) brachytherapy (BT) based on three-dimensional CT in locally advanced cervical cancer, as a simple and effective clinical treatment approach.
  
  
  
  Fifty-two patients with poor tumor response to external beam radiotherapy and a residual tumor >5 cm at the time of the first BT were included. IS BT was performed using a "hybrid" applicator combining uterine tandem and free metal needles based on three-dimensional CT. The high-risk clinical target volume (HR-CTV), intermediate-risk clinical target volume, and organs at risk were contoured. The total dose, including external beam radiotherapy (45 Gy in 25 fractions) and high-dose-rate BT (30 Gy in 5 fractions), was biologically normalized to conventional 2-Gy fractions. D90 and D100 for HR-CTV and intermediate-risk clinical target volume and D2cc for the bladder, rectum, and sigmoid were analyzed.
  
  
  
  The mean D90 value for HR-CTV was 88.4 ± 3.5 Gy. Totally, 88.5% of the patients received D90 for HR-CTV ≥87 Gy. The D2cc for the bladder, rectum, and sigmoid were 81.1 ± 5.6, 65.7 ± 5.1, and 63.1 ± 5.4 Gy, respectively. The mean number of needles was 6.9 ± 1.3 for each application. IS BT was associated with minor complications.
  
  
  
  IS BT using the "hybrid" applicator provides a dosimetric advantage for target volume and organs at risk in large-volume (>5 cm) tumors and is, thereby, clinically feasible. However, the long-term curative effect and possible toxicity need further clinical observation.
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Zhong-Shan
authors.initials: ZS
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Lin
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Hong-Yong
authors.initials: HY
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Ren
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Yun-Feng
authors.initials: YF
authors.lastname: Li
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China.
authors.forename: Bing-Ya
authors.initials: BY
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, The Second Hospital Affiliated by Jilin University, Changchun, China. Electronic address: wangtiejunjlu@sina.com.
authors.forename: Tie-Jun
authors.initials: TJ
authors.lastname: Wang
mesh_terms: D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D012809:Colon, Sigmoid; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008875:Middle Aged; D009339:Needles; D018365:Neoplasm, Residual; D058958:Organs at Risk; D011879:Radiotherapy Dosage; D012007:Rectum; D019233:Retreatment; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D001743:Urinary Bladder; D002583:Uterine Cervical Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy*
keywords: Cervical cancer; Computed tomography; Interstitial brachytherapy