Cooperative Brachytherapy Robotic Concept for Localized Cancer Treatment Under Real-Time MRI

Currently, localized cancer treatment is one of the focused research interests of Physicians. Indeed, with the advent of sensor and actuator technologies with the feasibility of integrating multiple systems, treatment and diagnosis have gained more interest in incorporating Magnetic Resonance Imaging (MRI) due to better soft-tissue contrast. In this paper, the authors report the development of the MR-based Cooperative Brachytherapy (CoBra) robot design for in-bore patient prostate intervention, in terms of diagnosis and treatment of localized cancers. The presented CoBra system is characterized by three main MR-compatible components: a suitable leg-support ensuring patient stabilization, a versatile robotized needle guide, and an automated implant driver to deposit precisely radioactive seeds. In fact, ergonomically in-bore needle placement is a challenging problem, whereas the CoBra robot aims to help in in-bore intra-operative intervention under closed-loop control based on imagery feedback. This feedback might be exploited judiciously for tracking online the biological target during changes after needle insertions. Within this framework, the paper discusses the CoBra robot with a focus on kinematics design, modeling, instrumentation, control, and MRI in-bore robot tests, with respect to the adopted clinical workflow. Also, Preliminary experimental results simulating an adaptive prostate LDR-BT under 3 Tesla MRI are given to validate the proposed concept.