ESTRO 2025 - Abstract Book

S481

Clinical - Breast

ESTRO 2025

Parameter

ACCEL Constraints

Our Data (Range)

V50%

<50% volume to receive >50% of prescribed dose

17.28% (8.02%- 25.23%)

V95%

<25% volume to receive >95% of prescribed dose

7.53% (3.65%- 10.55%)

V10%

<20% volume to receive >10% of prescribed dose

23.35% (11.5%- 41.6%)

V30%

<10% volume to receive >30% of prescribed dose

3.77% (0.41%- 9%)

V3%

<53% volume to receive >3% of prescribed dose

15.27% (1.6%- 30.5%)

Heart dose

Right breast: <5% volume to receive >5% of prescribed dose Left Breast: Lower inner quadrant <5% volume to receive >15% of prescribed dose

3.03% (0-6.37%)

All other quadrants: <5% volume to receive >10% of prescribed dose

Mean Heart Dose

0.464 Gy (0.05 Gy-1.16 Gy)

Mean Lung Dose

1.836 Gy (1.15 Gy-3.02 Gy)

No patient had any physician reported skin toxicity > grade 2.

Conclusion: Preliminary results of using the ACCEL protocol for APBI showed good dosimetric parameters and acceptable skin toxicities.

Keywords: APBI, CyberKnife, ACCEL

References: Grendarova P, Roumeliotis M, Quirk S,et al. Accelerated Partial Breast Irradiation Using 5 Daily Fractions: A Prospective, Phase 2, Multicenter Trial of Cosmetic Outcomes and Toxicity-ACCEL Final Results. Int J Radiat Oncol Biol Phys. 2024 Mar 15;118(4):1041-1048.

1372

Digital Poster Correlation of skin dose with PROM-based toxicity profiles in ultra-hypofractionated and standard breast cancer radiotherapy Gerd Heilemann 1,2 , Lukas Zimmermann 1,2 , Andreas Renner 1,2 , Leo Andexlinger 1,2 , Andreas Moser 1 , Dietmar Georg 1 , Stefan Konrad 1 , Joachim Widder 1 , Daniela Kauer-Dorner 1 , Barbara Knäusl 1,2