title: Selection of the optimal radiotherapy technique for locally advanced hepatocellular carcinoma.
abstract: OBJECTIVE
  Various techniques are available for radiotherapy of hepatocellular carcinoma, including three-dimensional conformal radiotherapy, linac-based intensity-modulated radiotherapy and helical tomotherapy. The purpose of this study was to determine the optimal radiotherapy technique for hepatocellular carcinoma.
  
  
  METHODS
  Between 2006 and 2007, 12 patients underwent helical tomotherapy for locally advanced hepatocellular carcinoma. Helical tomotherapy computerized radiotherapy planning was compared with the best computerized radiotherapy planning for three-dimensional conformal radiotherapy and linac-based intensity-modulated radiotherapy for the delivery of 60 Gy in 30 fractions. Tumor coverage was assessed by conformity index, radical dose homogeneity index and moderated dose homogeneity index. Computerized radiotherapy planning was also compared according to the tumor location.
  
  
  RESULTS
  Tumor coverage was shown to be significantly superior with helical tomotherapy as assessed by conformity index and moderated dose homogeneity index (P= 0.002 and 0.03, respectively). Helical tomotherapy showed significantly lower irradiated liver volume at 40, 50 and 60 Gy (V40, V50 and V60, P= 0.04, 0.03 and 0.01, respectively). On the contrary, the dose-volume of three-dimensional conformal radiotherapy at V20 was significantly smaller than those of linac-based intensity-modulated radiotherapy and helical tomotherapy in the remaining liver (P= 0.03). Linac-based intensity-modulated radiotherapy showed better sparing of the stomach compared with helical tomotherapy in the case of separated lesions in both lobes (12.3 vs. 24.6 Gy). Helical tomotherapy showed the high dose-volume exposure to the left kidney due to helical delivery in the right lobe lesion.
  
  
  CONCLUSIONS
  Helical tomotherapy achieved the best tumor coverage of the remaining normal liver. However, helical tomotherapy showed much exposure to the remaining liver at the lower dose region and left kidney.
authors.affiliation: Department of Radiation Oncology, Yonsei University Health System, 134 Shinchon-Dong, Seodaemoon-Gu, Seoul 120-752, Republic of Korea.
authors.forename: Ik Jae
authors.initials: IJ
authors.lastname: Lee
authors.forename: Jinsil
authors.initials: J
authors.lastname: Seong
authors.forename: Woong Sub
authors.initials: WS
authors.lastname: Koom
authors.forename: Yong Bae
authors.initials: YB
authors.lastname: Kim
authors.forename: Byeong Chul
authors.initials: BC
authors.lastname: Jeon
authors.forename: Joo Ho
authors.initials: JH
authors.lastname: Kim
authors.forename: Kwang Hyub
authors.initials: KH
authors.lastname: Han
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000473:pathology* / Q000532:radiotherapy*; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000473:pathology* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D011881:Radiotherapy, Computer-Assisted / Q000379:methods*; D020266:Radiotherapy, Conformal; D050397:Radiotherapy, Intensity-Modulated; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome