| 摘要: |
| 目的量化分析头颈部肿瘤放射治疗中不同解剖区域位置精度，为肿瘤靶区外放边界和危及器官的精准勾画提供参考。方法对34例行调强放射治疗（IMRT）的头颈部肿瘤患者共计182组锥形束CT（CBCT）图像资料进行分析，定义ClinicalROI为临床常用配准框，5个局部解剖区域（包括后枕骨区域、下颌骨腮腺区域、C1~C3区域、C4~C6区域、C7及以下区域）为配准框进行摆位误差分析及相关性分析，并计算不同解剖区域配准条件下靶区外放边界。结果在3个平移方向，ClinicalROI摆位误差在（0.17±0.17）cm以内，5个局部解剖区域摆位误差范围在（0.25±0.28）cm以内；其中C1~C3区域摆位误差与ClinicalROI区域的一致性最好，两者在X轴、Y轴、Z轴平移方向均呈极强相关（r=0.81、0.83、0.81，均P＜0.05）。根据不同解剖区域统计的摆位误差值计算3个平移方向外放边界，后枕骨区域、下颌骨腮腺区域、C4~C6区域、C7及以下区域外放边界需要＞0.5cm。结论头颈部肿瘤放射治疗中不同解剖区域位置精度不同，临床定义靶区外放边界和危及器官的精准勾画需要考虑局部摆位误差和解剖位置变化带来的影响。 |
| 关键词: 头颈部肿瘤 放射治疗 摆位误差 危及器官 |
| DOI：10.12056/j.issn.1006-2785.2018.40.13.2016-2126 |
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| Positional accuracy of various anatomical regions in head and neck cancer radiotherapy |
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Hangzhou Carcer Hospital
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| Abstract: |
| Objective To quantify the positional accuracy of various anatomical regions in head and neck cancer radiotherapy, providing the precise contouring for planned tumor volume(PTV) and organ at risk (OAR). Methods Total 182 cone beam-computed tomography (CBCT) image data from 34 patients with head and neck cancer undergoing intensity modulated radiation therapy (IMRT) were retrospectively analyzed. The clinical commonly used large region of interest (Clinical ROI) and five ROIs (occipital bone, mandibular and parotid gland, vertebrae C1-C3, C4-C6, and the vertebrae caudal of C7) were defined in the
planning CT as registration frame for analysis of setup error with CBCT image. The five local setup error was compared with global setup error and then margins were calculated. Results The setup error of clinical ROI was (0.17±0.17)cm and that of the local ROIs was within(0.25±0.28)cm. The setup error from vertebrae C1-C3 and clinical ROI were closely correlated (r=0.81-0.83, P＜0.01).The margin ranges from clinical ROI were within 0.5cm and the margin ranges from local ROIs were (0.15-0.76)cm.
Conclusion The positional accuracy from various anatomical regions is different in head and neck cancer radiotherapy. In modern precise radiotherapy for head and neck cancer, the influence from local setup error and deformation for margins and OARs should be assessed. |
| Key words: Cancer of the head and neck Radiotherapy Setup errors Organs at risk |
