Abstract

To evaluate the feasibility of tumor-tracking radiotherapy that does not consider tumor deformation during respiration. Four-dimensional computed tomography (4D-CT) data, which considers 10 phases of the respiration cycle, were acquired in 4 patients with lung cancer and 4 patients with liver cancer. Initial treatment plans were established at the end of the inhalation phase (phase 1). As a simulation of deformation-free tumor-tracking radiotherapy, the beam center of the initial plan was moved to the tumor center for all other phases, and the tumor shape acquired from phase 1 was used for all 10 phases. The feasibility of this method was analyzed based on assessment of equivalent uniform dose (EUD), homogeneity index (HI) and coverage index (COV). In photon radiation treatment, movement-induced dose reduction was not particularly significant, with 0.5%, 17.3% and 2.8% average variation in EUD, HI and COV, respectively. In proton radiation treatment, movement-induced dose reduction was more significant, with 0.3%, 40.5% and 2.2% average variation in EUD, HI and COV, respectively. Proton treatment is more sensitive to tumor movement than is photon treatment, and that it is reasonable to disregard tumor deformation during photon therapy employing tumor-tracking radiotherapy.

Details

Title
Feasibility of deformation-independent tumor-tracking radiotherapy during respiration
Author
Kim, Seonkyu; Yoon, Myonggeun; Shin, Dong; Kim, Dongwook; Lee, Sangyeob; Lee, Se; Park, Sung; Song, Sang
Pages
78-84
Publication year
2011
Publication date
Apr 2011
Publisher
Medknow Publications & Media Pvt. Ltd.
ISSN
09716203
e-ISSN
19983913
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
864545025
Copyright
Copyright Medknow Publications & Media Pvt Ltd Apr 2011