Robotic Systems for Radiation Therapy

Abstract

Medical robotics is an exciting and relatively new field. Robotics plays an important role in medical engineering. Medical robots were initially used in the 1980s, in the field of urology. Robotic arms were developed and used for prostate resection. They can also be highly specialized and assist in diagnosing and treating patients. While there is still much more work to be done, using robots can enhance medical treatments in terms of both the quality and accessibility of care. Using robots can help reduce human error and bring highly specialized information to remote areas without requiring physicians’ direct intervention. In radiation therapy, high-energy radiation from x-rays, gamma rays, neutrons, and other sources has been used to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive materials placed in the body near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). The usage of robotic systems to improve the cancer treatment outcome is a new field. This field overlaps with electronics, computer science, artificial intelligence, mechatronics, nanotechnology, and bioengineering. For this purpose, robots can be used in medical facilities to perform different tasks such as delivering radiation sources, real-time tumor tracking during radiation delivery or external beam delivery. The only product in the market for robotic radiotherapy is CyberKnife Robotic Radiosurgery System. The robotic system has provision for so-called real-time tracking during beam delivery. The device itself is a 6MV linear accelerator mounted on a six degree-of-freedom (DOF) Keller und Knappich Augsburg (KUKA) industrial robot. This system has real-time image-guided control. Consequently, there is a significantly long time delay (about 200 ms) between the acquisition of tumor coordinates and repositioning to the linear accelerator. The CyberKnife-KUKA robot with linear accelerator end-effector is suited for radiation therapy to any body sites. Its field size is restricted to the limited geometry of 12 discrete circular fields ranging from 5mm to 60mm in diameter. Therefore, the workspace is confined and the radiation therapy community has not fully embraced the idea of using an industrial articulated robotic manipulator yet. The details about CyberKnife robotic system are not included in this chapter. Consequently, the basic idea is to present the novel research results in the field of robotic radiation therapy and its applications.