TY - JOUR
T1 - Cooperative control with ultrasound guidance for radiation therapy
AU - Şen, Hasan Tutkun
AU - Cheng, Alexis
AU - Ding, Kai
AU - Boctor, Emad
AU - Wong, John
AU - Iordachita, Iulian
AU - Kazanzides, Peter
N1 - Funding Information:
Wolfgang Wein (ImFusion GmbH) and Bernhard Fuerst provided software assistance for ImFusion Suite. Muyinatu A. Lediju Bell contributed to the development of the workflow and the experiment design, and Russell H. Taylor provided guidance and mentorship for the experiments conducted. This work was supported in part by NIH R01 CA161613 and in part by Elekta AB.
Publisher Copyright:
© 2016 Şen, Cheng, Ding, Boctor, Wong, Iordachita and Kazanzides.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - Radiation therapy typically begins with the acquisition of a CT scan of the patient for planning, followed by multiple days where radiation is delivered according to the plan. This requires that the patient be reproducibly positioned (set up) on the radiation therapy device (linear accelerator) such that the radiation beams pass through the target. Modern linear accelerators provide cone-beam computed tomography (CBCT) imaging, but this does not provide sufficient contrast to discriminate many abdominal soft-tissue targets, and therefore patient setup is often done by aligning bony anatomy or implanted fiducials. Ultrasound (US) can be used to both assist with patient setup and to provide real-time monitoring of soft-tissue targets. However, one challenge is that the ultrasound probe contact pressure can deform the target area and cause discrepancies with the treatment plan. Another challenge is that radiation therapists typically do not have ultrasound experience and therefore cannot easily find the target in the US image. We propose cooperative control strategies to address both the challenges. First, we use cooperative control with virtual fixtures (VFs) to enable acquisition of a planning CT that includes the soft-tissue deformation. Then, for the patient setup during the treatment sessions, we propose to use real-time US image feedback to dynamically update the VFs; this co-manipulation strategy provides haptic cues that guide the therapist to correctly place the US probe. A phantom study is performed to demonstrate that the co-manipulation strategy enables inexperienced operators to quickly and accurately place the probe on a phantom to reproduce a desired reference image. This is a necessary step for patient setup and, by reproducing the reference image, creates soft-tissue deformations that are consistent with the treatment plan, thereby enabling real-time monitoring during treatment delivery.
AB - Radiation therapy typically begins with the acquisition of a CT scan of the patient for planning, followed by multiple days where radiation is delivered according to the plan. This requires that the patient be reproducibly positioned (set up) on the radiation therapy device (linear accelerator) such that the radiation beams pass through the target. Modern linear accelerators provide cone-beam computed tomography (CBCT) imaging, but this does not provide sufficient contrast to discriminate many abdominal soft-tissue targets, and therefore patient setup is often done by aligning bony anatomy or implanted fiducials. Ultrasound (US) can be used to both assist with patient setup and to provide real-time monitoring of soft-tissue targets. However, one challenge is that the ultrasound probe contact pressure can deform the target area and cause discrepancies with the treatment plan. Another challenge is that radiation therapists typically do not have ultrasound experience and therefore cannot easily find the target in the US image. We propose cooperative control strategies to address both the challenges. First, we use cooperative control with virtual fixtures (VFs) to enable acquisition of a planning CT that includes the soft-tissue deformation. Then, for the patient setup during the treatment sessions, we propose to use real-time US image feedback to dynamically update the VFs; this co-manipulation strategy provides haptic cues that guide the therapist to correctly place the US probe. A phantom study is performed to demonstrate that the co-manipulation strategy enables inexperienced operators to quickly and accurately place the probe on a phantom to reproduce a desired reference image. This is a necessary step for patient setup and, by reproducing the reference image, creates soft-tissue deformations that are consistent with the treatment plan, thereby enabling real-time monitoring during treatment delivery.
KW - Cooperative control
KW - Human-in-the-loop image servoing
KW - Robot-assisted radiotherapy
KW - Ultrasound guided radiotherapy
KW - Virtual fixtures
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U2 - 10.3389/frobt.2016.00049
DO - 10.3389/frobt.2016.00049
M3 - Article
AN - SCOPUS:85061907404
SN - 2296-9144
VL - 3
JO - Frontiers Robotics AI
JF - Frontiers Robotics AI
IS - AUG
M1 - 49
ER -