# Combination Treatment with Spacer Placement Surgery Followed by Particle Radiotherapy for Lymph Node Metastasis from Uterine Cancer

## TL;DR

This study shows that combining spacer placement surgery with particle radiotherapy improves outcomes for lymph node metastases from uterine cancer.

## Contribution

The study introduces a novel combination of spacer placement surgery and PRT to overcome treatment limitations near the gastrointestinal tract.

## Key findings

- The 3- and 5-year overall survival rates were 76.2% and 38.1%, respectively.
- Local control rates at 3 and 5 years were both 88.9%.
- Spacer placement improved PRT dose distribution and contributed to better outcomes.

## Abstract

The effectiveness of local treatment in lymph node metastasis from uterine cancer has been proven; the standard treatment is surgical intervention. Although radiotherapy, including particle radiotherapy (PRT), is an alternative local treatment, its application is often contraindicated owing to its proximity to the gastrointestinal tract. Combination treatment with spacer placement surgery followed by PRT is a potential solution to this problem. This study aimed to evaluate the outcomes of this combination treatment of lymph node metastases from uterine cancer.

Between December 2007 and March 2023, ten consecutive patients who underwent combination treatment comprising spacer placement surgery and subsequent PRT were assessed for treatment outcomes.

The median survival time was 53.5 months; the 3- and 5-year overall survival rates were 76.2% and 38.1%, respectively. The 3- and 5-year local control rates in all patients were both 88.9%. The median volume irradiated at 95% of the treatment planning dose (V95%) of the gross tumor volume, clinical target volume, and planning target volume were 100.0%, 99.8%, and 92.2%, respectively. The median dose intensity covering 95% of the target volume (D95%) of the gross tumor volume/planned dose, clinical target volume/planned dose, and planning target volume/planned dose were 98.9%, 99.0%, and 87.2%, respectively.

Spacer placement surgery contributed to the optimized PRT dose distribution and might have contributed to favorable local control and survival rates. This innovative combination treatment might have a significant effect on the treatment of lymph node metastases from uterine cancers.