title: 3D-image-guided HDR-brachytherapy versus 2D HDR - brachytherapy after external beam radiotherapy for early T-stage nasopharyngeal carcinoma.
abstract: BACKGROUND
  Two-dimensional high-dose-rate brachytherapy (2D-HDR-BT) is an effective method of dose escalation for local tumor control in early T-stage nasopharyngeal carcinoma (NPC). Treatment outcomes for 3D-image-guided high-dose-rate brachytherapy (3D-image-guided-HDR-BT) after external beam radiotherapy (ERT) have not been examined in early T-stage NPC patients. The current study was designed to evaluate whether addition of 3D-HDR-BT to ERT showed further improvement in treatment outcomes in patients with early T-stage NPC when compared to 2D-HDR-BT after ERT.
  
  
  METHODS
  The current study retrospectively analyzed and compared treatment outcomes for patients with nonmetastatic stage T1-2b NPC treated with 2D-HDR-BT (n =101) or 3D-HDR-BT (n =118) after ERT. Patients in both groups were treated with ERT at a mean dose of 60 Gy and a brachytherapy dose of 12Gy (8 ~ 20Gy), 2.5 ~ 5Gy per fraction under local anesthesia.
  
  
  RESULTS
  Compared to patients treated with 2D-HDR-BT after ERT, patients treated with 3D-HDR-BT after ERT showed improvement in five-year actuarial local control survival rates (p = 0.024), local/regional relapse-free survival rates (p = 0.038), and disease-free survival rates (p = 0.021). Multivariate analysis showed that NPC patients treated with 3D-HDR-BT had improved local control survival (p = 0.042). The incidence rates of acute or chronic complications were similar between two groups.
  
  
  CONCLUSIONS
  The current study showed that 3D-image-guided HDR-BT after ERT was an effective treatment modality for patients with stage T1-2 NPC with acceptable complications. The improvement in local tumor control and disease free survival is likely due to improved conformal dose distributions.
authors.forename: YuFeng
authors.initials: Y
authors.lastname: Ren
authors.forename: QuanCheng
authors.initials: Q
authors.lastname: Zhao
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
authors.forename: YingJuan
authors.initials: Y
authors.lastname: Huang
authors.forename: ZhenYu
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Radiation Oncology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, P,R,China. drcaoxinping@126.com.
authors.forename: XinPing
authors.initials: X
authors.lastname: Cao
authors.forename: Bin S
authors.initials: BS
authors.lastname: Teh
authors.forename: BiXiu
authors.initials: B
authors.lastname: Wen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000009:adverse effects / Q000379:methods*; D002277:Carcinoma; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult