A novel approach to an automated needle insertion in brachytherapy procedures

Abstract

One of the most challenging phases in interstitial brachytherapy is the placement of the needles. In these medical procedures, the needles are inserted inside the tissue to guide the positioning of the radioactive sources. The low-dose-rate radioactive sources are placed inside the tissue permanently, whereas a radioactive source in the high-dose-rate brachytherapy is temporarily placed in the desired positions so that the delivery of the prescription dose to the clinical targets can be achieved. Consequently, the precise needle placement directly influences the radiation dose delivery and the treatment outcomes of patients. Any deviation from the desired position of the radioactive sources can cause a suboptimal dose distribution and inadequate tumor coverage. Therefore, it is of significant importance to develop a robust and sophisticated tool that can perform the automatic needle placement with a high level of accuracy for different medical procedures and conditions. In this study, we propose a novel concept for the automatic needle insertion using a new miniature automated robotic system. The mathematical model of this system was presented in detail, allowing the implementation of the model predictive control that can be used to govern the mechanism. The purpose of this approach was to minimize the lateral components of the generalized reactive force which is responsible for the tissue displacement and, consequently, for the needle deflection. The proposed approach was designed to predict and to compensate for the unmeasured disturbances, such as needle deflection or tissue resistance and reactive force, and it was capable of correcting them without waiting until the effect appears at the output of the system causing the needle deviation from the desired positions. The extensive simulation of the system was presented to evaluate the feasibility of the method and the parameters of interest including displacements, system errors and system responses to the change in the environmental conditions.

Image‐guided robots for low dose rate prostate brachytherapy: Perspectives on safety in design and use

“…Accurate needle insertion and seed injection are critical for patient safety and device regulation. Needle placement, for the positioning of radioactive seeds, is one of the most challenging components of LDR prostate BT, as it directly affects dose delivery and treatment outcomes 63 . Even small seed positioning errors (>6 mm) 24 can result in unsatisfactory dose distributions and insufficient tumour coverage, often caused by needle deflection, prostate movement during insertion, intraoperative oedema, prostate deformation by the needle or US probe and the effects of drag during needle removal.…”

“…Needle placement, for the positioning of radioactive seeds, is one of the most challenging components of LDR prostate BT, as it directly affects dose delivery and treatment outcomes. 63 Even small seed positioning errors (>6 mm) 24 34 designed a multichannel BT robot to compensate for the limitations of single-needle insertion. However, the mechanical structure of this robot was large and the needles were required to be parallel.…”

Rupture Detection During Needle Insertion Using Complex OCT Data and CNNs

“…Moreover, the tissue is deformed and displaced by the needle [6], making it difficult to identify the exact position of the needle tip relative to the tissue and the target by only observing the shaft motion. Even if the needle is placed by a robot [7], the position of the needle relative to soft tissue targets is often difficult to assess. Hence, accurate detection of tissue boundaries and ruptures during needle insertions is required to allow for accurate navigation robust to relative motion.…”

Mathematical Model of Patient Support System in Medical Linear Accelerators for External Beam Radiation Therapy

“…Therefore, the various motion tracking and compensation techniques require dynamical motion of the all machine components involved in the radiation treatments such as dynamically moving MLC, couch motion compensation, and real-time imaging of the patients during treatments [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], etc. Dynamic model approach is becoming more utilized in other radiation therapy modalities [20]. The robotic treatment couches in EBRT are used for patient positioning.…”