ESTRO 2024 - Abstract Book

S449

Clinical - Breast

ESTRO 2024

(p<0.01); FB:3.2±2.0, DIBH:1.7±0.9, and CPAP:1.3±0.6 Gy in Breast+IMN-RT (p<0.01). LADDmean was FB:10.5±5.0, DIBH:5.1±3.4, and CPAP:2.3±1.0 Gy in Breast-RT (p<0.01); FB:15.7±9.2, DIBH:6.8±4.7, and CPAP:3.3±1.6 Gy in Breast+IMN-RT (p<0.01). A maximum dose to LAD (LADDmax) was FB:34.6±10.2, DIBH:20.5±16.1, and CPAP:7.9±6.4 Gy in Breast-RT (p<0.01); FB:38.9±5.9, DIBH:21.4±16.7, and CPAP:9.6±7.6 Gy in Breast+IMN-RT (p<0.01). All patients successfully completed CPAP-RT.

Conclusion:

CPAP-RT provides efficient and practical heart and LAD sparing RT using simple supine tangential fields for Breast RT or wide-tangential fields for Breast+IMN-RT when DIBH-RT was ineffective or unsuitable. With its easy accessibility and low infrastructural investment, CPAP-RT can provide affordable heart-sparing left breast RT to bridge the care gap in low-resource settings.

Keywords: Heart, DIBH, CPAP-assisted breathing RT

57

Poster Discussion

Whole Brain Radiotherapy vs. Stereotactic Radiosurgery in Patients with Brain Metastases from Breast

Budhi Singh Yadav 1 , Venkata Krishna Vamsi Gade 1 , Poorva Vias 2 , Ngangom Robert 1

1 Postgraduate Institute of Medical Education & Research, Radiotherapy & Oncology, Chandigarh, India. 2 RPMC, Radiotherapy, Kangra, India

Purpose/Objective:

To compare Whole Brain Radiotherapy(WBRT) with Stereotactic Radiosurgery (SRS) in patients with brain metastases from breast cancer.

Material/Methods:

Breast cancer patients who developed or presented with brain metastases were included in this study. Patients with 1 to 5 brain lesions, each with a maximum diameter of ≤3.5 cm on contrast enhanced magnetic resonance imaging (MRI) scans and ECOG performance status 0-1 were randomised to WBRT or SRS. WBRT dose was 30Gy/10#/2 weeks. SRS dose was prescribed as per the size and location of the lesion with respect to eloquent or critical structures. Single faction SRS (sSRS) dose varied from 18Gy to 24Gy. Fractionated SRS (fSRS) dose was 27Gy to 36Gy in 3-6 fractions. All fractions were delivered on consecutive days. Response was assessed after 3 months with CEMRI brain. Primary endpoint of the study was overall survival (OS) and the secondary end point was progression free survival (PFS). The trial was approved by the institute ethics committee and registered in Clinicaltrailsgov.in NCT05144867.