# Improvement of plan quality in whole-breast radiation following BCS using feasibility DVH by less-experienced planners

## TL;DR

This study shows that less experienced planners can create high-quality radiation plans for breast cancer patients using feasibility DVH tools, achieving results comparable to experienced planners.

## Contribution

The study demonstrates that feasibility DVH parameters can help less experienced planners produce high-quality VMAT plans for breast cancer.

## Key findings

- VMAT plans using feasibility DVH achieved PTV coverage and homogeneity comparable to those of experienced planners.
- The VMAT-FDVH group showed a significant reduction in mean ipsilateral lung dose by 0.9 Gy compared to the VMAT-EXP group.
- Feasibility DVH tools enabled less experienced planners to generate acceptable VMAT plans with lower lung doses.

## Abstract

Variability in plan quality of radiotherapy is commonly attributed to the planner’s skill rather than technological parameters. While experienced planners can set reasonable parameters before optimization, less experienced planners face challenges. This study aimed to assess the quality of volumetric-modulated arc therapy (VMAT) in patients with left-sided breast cancer following breast-conserving surgery. Twenty-eight patients requiring whole-breast irradiation were randomly selected for inclusion. Each patient underwent two VMAT treatment plans: one optimized by an experienced planner (VMAT-EXP group) and the other designed by a less experienced planner using feasibility dose-volume histogram (FDVH) parameters from PlanIQ (VMAT-FDVH group). Both plans aimed to deliver a prescription dose of 50 Gy in 25 fractions to the planning target volume (PTV). Dosimetry parameters for the PTV and organs at risk (OARs) were compared between the two groups. Both the VMAT-EXP and VMAT-FDVH groups met the clinical plan goals for PTV and OARs. VMAT-FDVH demonstrated a PTV coverage and homogeneity comparable to those of VMAT-EXP. Compared to VMAT-EXP plans, VMAT-FDVH plans resulted in a significant reduction in the mean ipsilateral lung dose, with an average decrease of 0.9 Gy (8.5 Gy vs. 7.6 Gy, P < 0.001). The V5Gy and V20Gy of the ipsilateral lung were also reduced by 3.2% and 1.8%, respectively. Minor differences were observed in the heart, contralateral lung, breast, and liver. Personalized objectives derived from the feasibility DVH tool facilitated the generation of acceptable VMAT plans. Less experienced planners achieved lower doses to the ipsilateral lung while maintaining adequate target coverage and homogeneity. These findings suggest the potential for the effective use of VMAT in in patients with left-sided breast cancer following breast-conserving surgery, especially when guided by feasibility DVH parameters.