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Updated: Aug 26, 2026
Stereotactic Radiosurgery for Gynecologic Cancer
Published on: April 17, 2012
[Analysis of target localization errors in fractionated stereotactic radiotherapy for head and neck carcinoma]
Li-Xin Chen1, Wen-Jie Li, Xiao-Hua He
1Department of Radiation, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, PR China. clxin@gzsums.edu.cn
Background & Objective:
Accurate target localization is the essential requirement in the quality control in fractionated stereotactic radiotherapy (FSRT). This paper is to analyze the magnitude of errors in FSRT for head and neck carcinoma including the errors of CT localization, mechanical isocenter, setup of patients, and CT image.
Methods:
The stereotactic radiotherapy treatment planning system (SRT-TPS), target simulator and head frame were used to check the errors of target localization during each radiation procedure. Five reference points were set randomly; the CT localization error was measured using the target simulator. Seven different mechanical angles of Gantry/Table were selected; the magnitude of isocentric errors of Philips SL-18 linear accelerator were acquired with films. Setup errors were collected by portal films. The image error possibly from CT image artifact was analyzed after scanning a self-made phantom by CT.
Results:
The CT localization error was(1.5+/-0.4)mm. The maximal error of the mechanical isocenter was (1.0+/-0.6)mm according to the different mechanical gantry/table angles. The distance error of patient setup was (1.0+/-0.3)mm. The maximal total errors estimate was (2.1+/-0.8)mm.
Conclusions:
The effect of target localization of every procedure should be taken in account in FSRT, the results of the error analysis can be used to determinate the planning target volume in the treatment.
