A novel adaptive needle insertion sequencing for robotic, single needle MR-guided high-dose-rate prostate brachytherapy

Abstract

MR-guided high-dose-rate (HDR) brachytherapy has gained increasing interest as a treatment for patients with localized prostate cancer because of the superior value of MRI for tumor and surrounding tissues localization. To enable needle insertion into the prostate with the patient in the MR bore, a single needle MR-compatible robotic system involving needle-by-needle dose delivery has been developed at our institution. Throughout the intervention, dose delivery may be impaired by: (1) sub-optimal needle positioning caused by e.g. needle bending, (2) intra-operative internal organ motion such as prostate rotations or swelling, or intra-procedural rectum or bladder filling. This may result in failure to reach clinical constraints. To assess the first aforementioned challenge, a recent study from our research group demonstrated that the deposited dose may be greatly improved by real-time adaptive planning with feedback on the actual needle positioning. However, the needle insertion sequence is left to the doctor and therefore, this may result in sub-optimal dose delivery. In this manuscript, a new method is proposed to determine and update automatically the needle insertion sequence. This strategy is based on the determination of the most sensitive needle track. The sensitivity of a needle track is defined as its impact on the dose distribution in case of sub-optimal positioning. A stochastic criterion is thus presented to determine each needle track sensitivity based on needle insertion simulations. To assess the proposed sequencing strategy, HDR prostate brachytherapy was simulated on 11 patients with varying number of needle insertions. Sub-optimal needle positioning was simulated at each insertion (modeled by typical random angulation errors). In 91% of the scenarios, the dose distribution improved when the needle was inserted into the most compared to the least sensitive needle track. The computation time for sequencing was less than 6 s per needle track. The proposed needle insertion sequencing can therefore assist in delivering an optimal dose in HDR prostate brachytherapy.

A review on the techniques used in prostate brachytherapy

“…While combing the MRI imaging and shared control strategy, Moreira et al [85] and Wartenberg et al [86] both have presented a similar shared control MRI-compatible system with robotics controlling the insertion direction and the surgeon controlling the insertion depth. An magnetic resonance (MR)-compatible single needle delivery robotics system is presented by de Battisti et al [87]. Based on identifying the most sensitive needle track, the proposed method could determine and automatically update the needle insertion route.…”

Review of Clinical and Technological Consideration for MRI-Guided Robotic Prostate Brachytherapy

“…Parameters like NT and MD accuracy were not reported. The team also presented the concept of adaptive HDR-BT needle insertion sequencing with provisions to integrate their MRrobot, and needle tracking with the aid of FBG sensors under an MRI environment [124].…”

Risk Management for the Reliability of Robotic Assisted Treatment of Non-resectable Liver Tumors

“…An efficient solution that can overcome the human limitations in such techniques is represented by the use of robotic systems which, based on careful preplanning of the procedure, enable tumor targeting with increased accuracy [6]. The most promising results have been achieved in the treatment of tumors located in the prostate [7], lung [8], or breast [9], but all studies reflected that the procedure difficulty increases as the tumors are located deeper in the body (as the access path is longer and needle orientation errors, especially, multiply) and is more complicated for organs with complex vascular structure. In fact, the therapeutic feasibility of HDR brachytherapy for HCC treatment is not yet proven, mostly due to the lack of accurate technical solutions capable of delivering the therapeutic agent in a reliable manner which facilitates patient safety and decreases the overall risk of the medical procedure.…”

“…Due to the promising outcomes in some areas of medial robotics (especially in percutaneous procedures [4,[6][7][8][9]) some medical experts (from the "Iuliu Hatieganu" University of Medicine and Pharmacy in Cluj-Napoca) believe that future advances in surgery and oncology may come also from the development of technical solutions that help the clinicians in performing the therapies. On the one hand, present advances in nuclear medicine and medicinal chemistry may provide increasingly better therapeutic agents, but on the other hand, technical solutions (e.g., robotic systems) may provide better ways to deliver the therapeutic agents.…”