Journal Article

Novel utilization and quantification of Xsight diaphragm tracking for respiratory motion compensation in Cyberknife Synchrony treatment of liver tumors

Zhang, Jianping, Xu, Benhua, Wang, Lin, Yang, Zhiyu, Xie, Chenyu, Li, Xiaobo

2024

Overview

Purpose The Xsight lung tracking system (XLTS) utilizes an advanced image processing algorithm to precisely identify the position of a tumor and determine its location in orthogonal x‐ray images, instead of finding fiducials, thereby minimizing the risk of fiducial insertion‐related side effects. To assess and gauge the effectiveness of CyberKnife Synchrony in treating liver tumors located in close proximity to or within the diaphragm, we employed the Xsight diaphragm tracking system (XDTS), which was based on the XLTS. Methods We looked back at the treatment logs of 11 patients (8/11 [XDTS], 3/11 [Fiducial‐based Target Tracking System‐FTTS]) who had liver tumors in close proximity to or within the diaphragm. And the results are compared with the patients who undergo the treatment of FTTS. The breathing data information was calculated as a rolling average to reduce the effect of irregular breathing. We tested the tracking accuracy with a dynamic phantom (18023‐A) on the basis of patient‐specific respiratory curve. Results The average values for the XDTS and FTTS correlation errors were 1.38 ± 0.65  versus 1.50 ± 0.26 mm (superior‐inferior), 1.28 ± 0.48  versus 0.40 ± 0.09 mm (left‐right), and 0.96 ± 0.32  versus 0.47 ± 0.10 mm(anterior‐posterior), respectively. The prediction errors for two methods of 0.65 ± 0.16  versus 5.48 ± 3.33 mm in the S‐I direction, 0.34 ± 0.10  versus 1.41 ± 0.76 mm in the A‐P direction, and 0.22 ± 0.072  versus 1.22 ± 0.48 mm in the L‐R direction. The coverage rate of FTTS slightly less than that of XDTS, such as 96.53 ± 8.19% (FTTS) versus 98.03 ± 1.54 (XDTS). The prediction error, the motion amplitude, and the variation of the respiratory center phase were strongly related to each other. Especially, the higher the amplitude and the variation, the higher the prediction error. Conclusion The diaphragm has the potential to serve as an alternative to gold fiducial markers for detecting liver tumors in close proximity or within it. We also found that we needed to reduce the motion amplitude and train the respiration of the patients during liver radiotherapy, as well as control and evaluate their breathing.

• Publisher: John Wiley & Sons, Inc
• Subject: Ablation / accumulated target coverage / Aged / Algorithms / Coordinate transformations / Diaphragm - diagnostic imaging / Female / Fiducial Markers / Humans / Image Processing, Computer-Assisted - methods / Liver cancer / Liver Neoplasms - diagnostic imaging / Liver Neoplasms - radiotherapy / Liver Neoplasms - surgery / liver tumor / Lung cancer / Male / Metastasis / Middle Aged / Movement / Organs at Risk - radiation effects / Patients / Phantoms, Imaging / Prognosis / Radiation therapy / Radiosurgery - methods / Radiotherapy Dosage / Radiotherapy Planning, Computer-Assisted - methods / Radiotherapy, Image-Guided - methods / Radiotherapy, Intensity-Modulated - methods / Respiration / respiratory motion compensation / Tumors / X-rays / Xsight diaphragm tracking