The accuracy of placement during radiotherapy significantly affects treatment quality. During the current and subsequent fractions of radiotherapy treatment (RTT), positional mismatching between the initial CT-scanned location and the current physical state reduces efficiency in RTT. In general, this situation requires doctors to perform freehand adjustment in RTT to adapt the current alteration of patients and guarantee the effectiveness of the plan, which is described as “plan adapts to tumor,” and is typically cumbersome. To mitigate such drawback, we designed a morphological robotic system that can keep a patient's posture identical with the first fraction. Furthermore, we directly adjusted nonrigid tumor deformation. Hence, the system achieved high-level matching accuracy between the current and initial physical states, which is notably described as “tumor adapts to plan.” Our proposed robotic system consists of a pilot circuit, morphological and mechanical structures, and operating software. A series of experiments was conducted to prove the feasibility and precision of the developed system. Results showed that the proposed robotic system can maintain the same posture as the first fraction. It exhibits the potential to become an efficient solution in radiotherapy.
