title: Dosimetric comparison of intensity modulated radiotherapy and three-dimensional conformal radiotherapy in patients with gynecologic malignancies: a systematic review and meta-analysis.
abstract: BACKGROUND
  To quantitatively evaluate the safety and related-toxicities of intensity modulated radiotherapy (IMRT) dose-volume histograms (DVHs), as compared to the conventional three-dimensional conformal radiotherapy (3D-CRT), in gynecologic malignancy patients by systematic review of the related publications and meta-analysis.
  
  
  METHODS
  Relevant articles were retrieved from the PubMed, Embase, and Cochrane Library databases up to August 2011. Two independent reviewers assessed the included studies and extracted data. Pooled average percent irradiated volumes of adjacent non-cancerous tissues were calculated and compared between IMRT and 3D-CRT for a range of common radiation doses (5-45 Gy).
  
  
  RESULTS
  In total, 13 articles comprised of 222 IMRT-treated and 233 3D-CRT-treated patients were included. For rectum receiving doses ≥30 Gy, the IMRT pooled average irradiated volumes were less than those from 3D-CRT by 26.40% (30 Gy, p = 0.004), 27.00% (35 Gy, p = 0.040), 37.30% (40 Gy, p = 0.006), and 39.50% (45 Gy, p = 0.002). Reduction in irradiated small bowel was also observed for IMRT-delivered 40 Gy and 45 Gy (by 17.80% (p = 0.043) and 17.30% (p = 0.012), respectively), as compared with 3D-CRT. However, there were no significant differences in the IMRT and 3D-CRT pooled average percent volumes of irradiated small bowel or rectum from lower doses, or in the bladder or bone marrow from any of the doses. IMRT-treated patients did not experience more severe acute or chronic toxicities than 3D-CRT-treated patients.
  
  
  CONCLUSIONS
  IMRT-delivered high radiation dose produced significantly less average percent volumes of irradiated rectum and small bowel than 3D-CRT, but did not differentially affect the average percent volumes in the bladder and bone marrow.
authors.affiliation: Department of Gynecologic Oncology, Cancer Hospital of Harbin Medical University, 150 Haping Street, Nangang District, Harbin, Heilongjiang Province, PR China.
authors.forename: Baojuan
authors.initials: B
authors.lastname: Yang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.forename: Haiyan
authors.initials: H
authors.lastname: Cheng
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Yunyan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yashuang
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D005260:Female; D005833:Genital Neoplasms, Female / Q000532:radiotherapy*; D006801:Humans; D058958:Organs at Risk / Q000528:radiation effects*; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*