The geometric accuracy of frameless stereotactic radiosurgery using a 6D robotic couch system

Abstract

The aim of this paper is to assess the overall geometric accuracy of the Novalis system using the Robotic Tilt Module in terms of the uncertainty in frameless stereotactic radiotherapy. We analyzed the following three metrics: (1) the correction accuracy of the robotic couch, (2) the uncertainty of the isocenter position with gantry and couch rotation, and (3) the shift in position between the isocenter and central point detected with the ExacTrac x-ray system. Based on the concept of uncertainty, the overall accuracy was calculated from these values. The accuracy in positional correction with the robotic couch was 0.07 +/- 0.22 mm, the positional shift of the isocenter associated with gantry rotation was 0.35 mm, the positional shift of the isocenter associated with couch rotation was 0.38 mm and the difference in position between the isocenter and the ExacTrac x-ray system was 0.30 mm. The accuracy of intracranial stereotactic radiosurgery with the Novalis system in our clinic was 0.31 +/- 0.77 mm. The overall geometric accuracy based on the concept of uncertainty was 0.31 +/- 0.77 mm, which is within the tolerance given in the American Association of Physicists in Medicine report no. 54.

Correction of motion‐induced misalignment in co‐registered PET/CT and MRI (T1/T2/FLAIR) head images for stereotactic radiosurgery

“…( 17 , 18 ) Therefore, diagnostic images can be utilized through volumetric image registration with a level of accuracy sufficient for SRS. In a trend of increasing clinical implementations of image‐guided frameless SRS, ( 25 , 26 ) where stereotactic imaging is not possible, the 3DVIR could be applied to achieve the accuracy of stereotactic imaging for target delineation and localization, and to perform image‐guided stereotactic setup for frameless SRS delivery.…”

Treatment accuracy without rotational setup corrections in intracranial SRT

“…To further increase accuracy in cranial SRT, patient rotational setup errors can be corrected using a six degrees of freedom (6DOF) couch 17 , 18 , 19 . In all of these studies, the correction of the rotational setup error increased plan quality and organ‐at‐risk (OAR) sparing.…”

SU‐E‐J‐12: An Image‐Guided Soft Robotic Patient Positioning System for Maskless Head‐And‐Neck Cancer Radiotherapy: A Proof‐Of‐Concept Study

“…Treatment discomfort and severe pain often results from long hours of minimally invasive surgery where the skull is fixed with pins for head immobilization during stereo-tactic radiosurgery (SRS). In addition, conventional linear accelerators (LINACs) used at most cancer centers are insufficient for the high geometric accuracy and precision required of SRS for isocenter localization [3]. Image-guided radiotherapy (IGRT) has made progress in improving accuracy while reducing set-up times [3], [4], [5].…”

“…In addition, conventional linear accelerators (LINACs) used at most cancer centers are insufficient for the high geometric accuracy and precision required of SRS for isocenter localization [3]. Image-guided radiotherapy (IGRT) has made progress in improving accuracy while reducing set-up times [3], [4], [5]. The Robotic Tilt Module (RTM) interfaced with an imageguidance system [3], [6] enables high-precision positional correction by automatically aligning the patient when the image-guidance system detects positional errors.…”