Effects of different registration methods for Tomotherapy MVCT on head and neck positioning(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第7期
- Page:
- 798-803
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Effects of different registration methods for Tomotherapy MVCT on head and neck positioning
- Author(s):
- CAO Panpan; PENG Haiyan; MENG Wanli; LI Shi; HE Yang; LUO Huanli; MAO Kaijin; YAN Tingcan; WANG Xiyi; RAN Xueqi; JIN Fu
- Department of Radiation Oncology, Chongqing University Cancer Hospital/Chongqing Cancer Hospital/Chongqing Cancer Institute, Chongqing 400030, China
- Keywords:
- Keywords: Tomotherapy megavoltage computed tomography reconstructed slice thickness image registration
- PACS:
- R318；R811.1
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.07.002
- Abstract:
- Abstract: Objective To evaluate the effects of different registration methods for Tomotherapy megavoltage computed tomography (MVCT) on head and neck positioning. Methods The head-and-neck phantom was positioned based on indoor laser and body surface markers and then received MVCT scan. After automatic image registration and error correction, the obtained image was used as the reference. Subsequently, the treatment couch was artificially moved in single, 2 and 3 directions (from -5 to 5 mm, with a step length of 1 mm). Three different kinds of methods, namely Bone, Bone and Tissue, Full Image, were adopted for image registration. The positioning errors in left-right (X), superior-inferior (Y) and anterior-posterior (Z) directions were recorded. Results When adopting Bone for image registration, the positioning errors were the smallest. In Fine 1 mm and 2 mm modes, there were significant variations for the positioning errors between registration using Bone and registration using Bone and Tissue, and the positioning errors were 0.5 (0.3, 0.8) mm and 0.6 (0.4, 0.8) mm for Fine 1 mm mode, and 0.4 (0.3, 0.7) mm and 0.5 (0.4, 0.8) mm for Fine 2 mm mode. In Normal 2 mm and Coarse 3 mm modes, there were significant differences among 3 registration methods (P<0.05) while in Fine 2 mm and Normal 2 mm modes, no significant difference was found (P>0.05). Whatever registration method was adopted, the correlation in Y direction was the lowest. The CTV-PTV Margin in X, Y and Z directions were 2.1, 2.8, 2.2 mm for Bone, 2.1, 2.7, 2.2 mm for Bone and Tissue, and 2.2, 3.0, 2.2 mm for Full Image, respectively. Conclusion Based on the comprehensive consideration on 3 modes, with the same scan length, scan time and dose, Normal mode combined with Bone is preferentially recommended in clinical Tomotherapy for patients with head and neck cancer.
Last Update: 2021-07-26