title: Evaluation of radiosurgery techniques--cone-based linac radiosurgery vs tomotherapy-based radiosurgery.
abstract: Performances of radiosurgery of intracranial lesions between cone-based Linac system and Tomotherapy-based system were compared in terms of dosimetry and time. Twelve patients with single intracranial lesion treated with cone-based Linac radiosurgery system from 2005 to 2009 were replanned for Tomotherapy-based radiosurgery treatment. The conformity index, homogeneity index (HI), and gradient score index (GSI) of each case was calculated. The Wilcoxon matched-pair test was used to compare the 3 indices between both systems. The cases with regular target (n = 6) and those with irregular target (n = 6) were further analyzed separately. The estimated treatment time between both systems was also compared. Significant differences were found in HI (p = 0.05) and in GSI (p = 0.03) for the whole group. Cone-based radiosurgery was better in GSI whereas Tomotherapy-based radiosurgery was better in HI. Cone-based radiosurgery was better in conformity index (p = 0.03) and GSI (p = 0.03) for regular targets, whereas Tomotherapy-based radiosurgery system performed significantly better in HI (p = 0.03) for irregular targets. The estimated total treatment time for Tomotherapy-based radiosurgery ranged from 24 minutes to 35 minutes, including 15 minutes of pretreatment megavoltage computed tomography (MVCT) and image registration, whereas that for cone-based radiosurgery ranged from 15 minutes for 1 isocenter to 75 minutes for 5 isocenters. As a rule of thumb, Tomotherapy-based radiosurgery system should be the first-line treatment for irregular lesions because of better dose homogeneity and shorter treatment time. Cone-based Linac radiosurgery system should be the treatment of choice for regular targets because of the better dose conformity, rapid dose fall-off, and reasonable treatment time.
authors: Department of Radiotherapy, Hong Kong Sanatorium & Hospital, Happy Valley, Hong Kong, People's Republic of China. hoyinyip@yahoo.com.hk
authors: Ho Yin
authors: HY
authors: Yip
authors: Wing Lun A
authors: WL
authors: Mui
authors: Joseph W Y
authors: JW
authors: Lee
authors: Winky Wing Ki
authors: WW
authors: Fung
authors: Jocelyn M T
authors: JM
authors: Chan
authors: G
authors: G
authors: Chiu
authors: Maria Y Y
authors: MY
authors: Law
mesh_terms: D001932:Brain Neoplasms / Q000601:surgery*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D010315:Particle Accelerators / Q000295:instrumentation*; D011874:Radiometry / Q000379:methods*; D016634:Radiosurgery / Q000295:instrumentation* / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity