# Clinical application of real-time tumor-tracking for stereotactic volumetric modulated arc therapy for liver tumors

## TL;DR

This study shows that real-time tumor-tracking during liver radiation therapy is feasible and improves treatment accuracy and safety.

## Contribution

Demonstrates clinical feasibility of real-time tumor-tracking for liver stereotactic radiation therapy.

## Key findings

- Treatment time per fraction was under 10 minutes.
- RT-VMAT improved target conformity and organ sparing compared to 3D conformal radiotherapy.

## Abstract

•Respiratory-gated volumetric arc therapy with internal markers is clinically feasible.•Mean treatment time for stereotactic liver irradiation was below 10 min.•Target conformity and stomach-sparing profit from gated volumetric arc therapy.

Respiratory-gated volumetric arc therapy with internal markers is clinically feasible.

Mean treatment time for stereotactic liver irradiation was below 10 min.

Target conformity and stomach-sparing profit from gated volumetric arc therapy.

Real-time tumor-tracking volumetric modulated arc therapy (RT-VMAT) enabling beam-gating based on continuous X-ray tracking of the three-dimensional position of internal markers is relevant for moving tumors. Dose-volume characteristics and treatment time were evaluated in ten consecutive patients who underwent liver stereotactic body radiation therapy with RT-VMAT. Target dose conformity and sparing of the stomach and the intestine were improved comparing RT-VMAT with RT-3D conformal radiotherapy. The mean treatment time for each fraction was less than 10 min. RT-VMAT could be effective, especially for targets located adjacent to organs at risk.