Relevant reduction effect with a modified thermoplastic mask of rotational error for glottic cancer in IMRT
详细信息 查看全文
- 作者：Jae Hong Jung ; Joo-Young Jung ; Kwang Hwan Cho…
- 关键词：Patient setup errors ; Thermoplastic mask ; Glottis ; Correlation ; Tomotherapy
- 刊名：Journal of the Korean Physical Society
- 出版年：2017
- 出版时间：February 2017
- 年：2017
- 卷：70
- 期：3
- 页码：308-316
- 全文大小：
- 刊物主题：Physics, general; Theoretical, Mathematical and Computational Physics; Particle and Nuclear Physics;
- 出版者：The Korean Physical Society
- ISSN：1976-8524
- 卷排序：70
文摘
The purpose of this study was to analyze the glottis rotational error (GRE) by using a thermoplastic mask for patients with the glottic cancer undergoing intensity-modulated radiation therapy (IMRT). We selected 20 patients with glottic cancer who had received IMRT by using the tomotherapy. The image modalities with both kilovoltage computed tomography (planning kVCT) and megavoltage CT (daily MVCT) images were used for evaluating the error. Six anatomical landmarks in the image were defined to evaluate a correlation between the absolute GRE (°) and the length of contact with the underlying skin of the patient by the mask (mask, mm). We also statistically analyzed the results by using the Pearson’s correlation coefficient and a linear regression analysis (P <0.05). The mask and the absolute GRE were verified to have a statistical correlation (P < 0.01). We found a statistical significance for each parameter in the linear regression analysis (mask versus absolute roll: P = 0.004 [P < 0.05]; mask versus 3D-error: P = 0.000 [P < 0.05]). The range of the 3D-errors with contact by the mask was from 1.2% - 39.7% between the maximumand no-contact case in this study. A thermoplastic mask with a tight, increased contact area may possibly contribute to the uncertainty of the reproducibility as a variation of the absolute GRE. Thus, we suggest that a modified mask, such as one that covers only the glottis area, can significantly reduce the patients’ setup errors during the treatment.