Polar-coordinated contour processing algorithm in optimizing SCART treatment volume

Spatially Fractionated Radiation Therapy (SFRT) has emerged as an appealing approach in radiation oncology due to its outstanding performance in tumor control and ability to preserve normal tissues. With the introduction of Stereotactic Centralized Ablative Radiation Therapy (SCART) as a new approach of SFRT techniques ablating the core of bulky tumor, a notable number of patients have been treated globally. However, SCART Treatment Volumes (STVs) are usually manually generated by physicist based on GTV volume using the contour editing tool of the treatment planning systems (TPS). It is not only tedious but also suboptimal in terms of desired position, shape and volume. To overcome these challenges, our group proposed a creative algorithm based on polar-coordinated calculations principle to help physicist generate the STV. This approach has achieved several improvements, reducing time by approximately 90% and minimizing the need for recontouring. In addition, the STVs demonstrated a 15% increase in volume, as well as an enhanced conformality comparing with manual contour. This method has improved both efficiency and reproducibility of SCART planning with optimal STV.