Head and neck (H&N) cancer patients often present anatomical and geometrical changes in tumors and organs at risk (OARs) during radiotherapy treatment. These changes may result in the need to adapt the existing treatment planning, using an expert’s subjective opinion, for offline adaptive radiotherapy and a new treatment planning before each treatment, for online adaptive radiotherapy. In the present study, a fast methodology is proposed to assist in planning adaptation clinical decision using tumor and parotid glands percentage volume changes during treatment. The proposed approach was applied to 40 Η&Ν cases, with one planning Computed Tomography (pCT) image and CBCT scans for 6 weeks of treatment per case. Deformable registration was used for each patient’s pCT image alignment to its weekly CBCT. The calculated transformations were used to align each patient’s anatomical structures to the weekly anatomy. Clinical target volume (CTV) and parotid gland volume percentage changes were calculated in each case. The accuracy of the achieved image alignment was validated qualitatively and quantitatively. Furthermore, statistical analysis was performed to test if there is a statistically significant correlation between CTV and parotid glands volume percentage changes. Average MDA for CTV and parotid glands between corresponding structures defined by an expert in CBCTs and automatically calculated through registration was 1.40.1 mm and 1.50.1 mm, respectively. The mean registration time of the first CBCT image registration for 40 cases was lower than 3.4 min. Five patients show more than 20% tumor volume change. Six patients show more than 30% parotid glands volume change. Ten out of 40 patients proposed for planning adaptation. All the statistical tests performed showed no correlation between CTV/parotid glands percentage volume changes. The aim to assist in clinical decision making on a fast and automatic way was achieved using the proposed methodology, thereby reducing workload in clinical practice.

头颈部 (H&N) 癌症患者在放射治疗期间经常出现肿瘤和危险器官 (OAR) 的解剖和几何变化。这些变化可能导致需要使用专家的主观意见来调整现有的治疗计划，以进行离线自适应放射治疗，并在每次治疗前调整新的治疗计划，以进行在线自适应放射治疗。在本研究中，提出了一种快速方法来帮助规划适应临床决策，使用治疗期间肿瘤和腮腺百分比体积变化。所提出的方法应用于 40 例 H&N 病例，每个病例使用一个计划计算机断层扫描 (pCT) 图像和 CBCT 扫描进行 6 周的治疗。可变形配准用于每位患者的 pCT 图像与其每周 CBCT 的对齐。计算出的转换用于将每个患者的解剖结构与每周的解剖结构对齐。在每种情况下计算临床目标体积 (CTV) 和腮腺体积百分比变化。定性和定量验证了所实现的图像对齐的准确性。此外，进行统​​计分析以测试 CTV 和腮腺体积百分比变化之间是否存在统计学上显着的相关性。CBCT 专家定义并通过配准自动计算的相应结构之间的 CTV 和腮腺的平均 MDA 分别为 1.40.1 毫米和 1.50.1 毫米。40 例 CBCT 图像配准的平均配准时间低于 3.4 分钟。五名患者表现出超过 20% 的肿瘤体积变化。六名患者表现出超过 30% 的腮腺体积变化。40 名患者中有 10 名建议进行计划调整。进行的所有统计测试显示 CTV/腮腺百分比体积变化之间没有相关性。使用所提出的方法实现了以快速和自动的方式协助临床决策的目的，从而减少了临床实践中的工作量。