Department of Human Oncology, University of Wisconsin-Madison, Madison, WI, USA.
Radiat Oncol. 2012 Jun 15;7:90. doi: 10.1186/1748-717X-7-90.
Adaptive Radiotherapy aims to identify anatomical deviations during a radiotherapy course and modify the treatment plan to maintain treatment objectives. This requires regions of interest (ROIs) to be defined using the most recent imaging data. This study investigates the clinical utility of using deformable image registration (DIR) to automatically propagate ROIs.
Target (GTV) and organ-at-risk (OAR) ROIs were non-rigidly propagated from a planning CT scan to a per-treatment CT scan for 22 patients. Propagated ROIs were quantitatively compared with expert physician-drawn ROIs on the per-treatment scan using Dice scores and mean slicewise Hausdorff distances, and center of mass distances for GTVs. The propagated ROIs were qualitatively examined by experts and scored based on their clinical utility.
Good agreement between the DIR-propagated ROIs and expert-drawn ROIs was observed based on the metrics used. 94% of all ROIs generated using DIR were scored as being clinically useful, requiring minimal or no edits. However, 27% (12/44) of the GTVs required major edits.
DIR was successfully used on 22 patients to propagate target and OAR structures for ART with good anatomical agreement for OARs. It is recommended that propagated target structures be thoroughly reviewed by the treating physician.
自适应放疗旨在识别放疗过程中的解剖学偏差，并修改治疗计划以维持治疗目标。这需要使用最新的成像数据来定义感兴趣区域 (ROI)。本研究探讨了使用变形图像配准 (DIR) 自动传播 ROI 的临床实用性。
为 22 名患者，将靶区 (GTV) 和危及器官 (OAR) 的 ROI 从计划 CT 扫描非刚性地传播到每次治疗的 CT 扫描。使用 Dice 评分和平均切片 Hausdorff 距离以及 GTV 的质心距离，对传播后的 ROI 与治疗时扫描的专家绘制的 ROI 进行定量比较。专家对传播后的 ROI 进行了定性检查，并根据其临床实用性进行了评分。
根据使用的指标，观察到 DIR 传播的 ROI 与专家绘制的 ROI 之间具有良好的一致性。使用 DIR 生成的所有 ROI 中，有 94%被评为具有临床实用性，只需进行最小或无需编辑。然而，27%（12/44）的 GTV 需要进行重大编辑。
DIR 在 22 名患者中成功用于 ART 的靶区和 OAR 结构的传播，OAR 的解剖学一致性良好。建议由主治医生对传播的靶区结构进行全面审查。
