Evaluation of radiosurgery techniques–Cone-based linac radiosurgery vs tomotherapy-based radiosurgery

Journal Article · Mon Jul 01 04:00:00 EDT 2013 · Medical Dosimetry

DOI:https://doi.org/10.1016/J.MEDDOS.2013.01.001· OSTI ID:22262810

Mui, Wing Lun A.; Lee, Joseph W.Y.; Fung, Winky Wing Ki; Chan, Jocelyn M.T.; Chiu, G. ^[1]; Law, Maria Y.Y. ^[2]

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1. Department of Radiotherapy, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong (China)
2. Medical Physics and Research Department, Hong Kong Sanatorium and Hospital, Happy Valley, Hong Kong (China)

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.

• OSTI ID: 22262810
• Journal Information: Medical Dosimetry, Journal Name: Medical Dosimetry Journal Issue: 2 Vol. 38; ISSN 0958-3947
• Country of Publication: United States
• Language: English

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