title: Proton radiotherapy for liver tumors: dosimetric advantages over photon plans.
abstract: The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V(30)) and the mean liver dose. The stomach and duodenal V(45) were significantly lower with the use of proton radiotherapy. The V(40) and V(50) of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.
authors.affiliation: Department of Radiation Physics, The University of Texas, M. D. Anderson Cancer Center, Houston, TX 77030, USA. springxwang@yahoo.com
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Wang
authors.forename: Sunil
authors.initials: S
authors.lastname: Krishnan
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Tina
authors.initials: T
authors.lastname: Briere
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Crane
authors.forename: Mary
authors.initials: M
authors.lastname: Martel
authors.forename: Michael
authors.initials: M
authors.lastname: Gillin
authors.forename: Radhe
authors.initials: R
authors.lastname: Mohan
authors.forename: Sam
authors.initials: S
authors.lastname: Beddar
mesh_terms: D006801:Humans; D008113:Liver Neoplasms / Q000532:radiotherapy*; D017785:Photons / Q000627:therapeutic use*; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D011522:Protons
chemical_list: D011522:Protons