Accuracy of needle implantation in brachytherapy using a medical AR system: a phantom study

Abstract

Brachytherapy is the treatment method of choice for patients with a tumor relapse after a radiation therapy with external beams or tumors in regions with sensitive surrounding organs-at-risk, e. g. prostate tumors. The standard needle implantation procedure in brachytherapy uses pre-operatively acquired image data displayed as slices on a monitor beneath the operation table. Since this information allows only a rough orientation for the surgeon, the position of the needles has to be verified repeatedly during the intervention. Within the project Medarpa a transparent display being the core component of a medical Augmented Reality (AR) system has been developed. There, pre-operatively acquired image data is displayed together with the position of the tracked instrument allowing a navigated implantation of the brachytherapy needles. The surgeon is enabled to see the anatomical information as well as the virtual instrument in front of the operation area. Thus, the Medarpa system serves as 'window into the patient'. This paper deals with the results of first clinical trials of the system. Phantoms have been used for evaluating the achieved accuracy of the needle implantation. This has been done by comparing the output of the system (instrument positions relative to the phantom) with the real positions of the needles measured by means of a verification CT scan.

Supporting minimal invasive interventions with augmented reality

“…The navigation accuracy of the system has been evaluated in the clinical environment [4] by needle insertions into phantoms using a second CT scan after the insertion for control. This allows a measurement of the accuracy within the limits of CT resolution.…”

Transparent OLED Displays

“…In medicine, there are studies that use so-called augmented reality systems based on transparent displays that supply the surgeons, e.g. during brachytherapy [2], with important data without them having to change their line of vision.…”

Advanced Medical Displays: A Literature Review of Augmented Reality

“…Wesarg et al [40] suggest a monoscopic AR window based on a transparent display. The design offers a compact setup, since no mirror is used, and no special glasses are required.…”