# Planning Non‐Linear Trajectories for No‐Touch Thermal Ablation Using Passive Steerable Needle With Controlled Stiffness and PSAM

## TL;DR

This paper introduces a new method called PSAM to plan thermal ablation procedures using a flexible needle, reducing risks and avoiding multiple insertions.

## Contribution

The novel PSAM method optimizes non-linear ablation trajectories with safety constraints using a passive steerable needle.

## Key findings

- PSAM outperformed manual and Monte Carlo planning in optimizing ablation trajectories.
- The ARC needle with controlled stiffness enabled single-insertion no-touch ablations.
- PSAM reduced damage to healthy tissue while respecting anatomical safety distances.

## Abstract

Percutaneous thermal ablation using a passive steering needle has the potential to help reduce procedure risks and enable multiple ablations with a single insertion. However, manual planning of such procedures is challenging, time‐consuming, and typically done using CT‐scans or tools designed for rigid or active steering needles. We introduce the PSAM approach which is based on an enhanced version of the particle swarm optimization with a memory component. This tool calculates optimal trajectories for no‐touch thermal ablations, considering safety distances from obstacles such as bones and organs, and the amount of ablation affecting healthy tissue. Experiments were conducted on a passive steerable needle with controlled stiffness named ARC needle recently developed. The results are then compared with a semi‐exhaustive Monte‐Carlo approach and a manual planning by a trained surgeon using conventional rigid needles, and ranked by a second expert. The results demonstrate the interest and potential of the ARC needle and the PSAM approach to achieve the no‐touch approach and avoid multiple insertions.

This study introduces PSAM, a planning method based on an enhanced particle swarm optimization with memory, to optimize trajectories for no‐touch thermal ablation using a passively steerable needle. It accounts for anatomical safety constraints and minimises damage to healthy tissue. Experiments with the new ARC needle show that PSAM outperforms manual and Monte Carlo planning, demonstrating its potential to reduce procedure risks and achieve effective ablations with a single insertion.