ESTRO 2023 - Abstract Book

S1028

Digital Posters

ESTRO 2023

Salvage repeated RT for locoregional recurrent breast cancer induced SAL in 23.1% of the patients. Salvage taxane-based chemotherapy and lateral to ALTJ V30Gy ≥ 55.8% significantly increased the risk of SAL. Incorporating lateral to ALTJ V30Gy into dose constraints and early consult to the department of rehabilitation could be helpful to reduce SAL when planning salvage repeated RT for locoregional breast cancer.

PO-1285 Post pandemic ultra-hypofractionated radiation in breast cancer from a tertiary Institution in India

H. Bhosale 1 , N. Hanumanthappa 1 , S. Basu 1 , P. Chadha 1 , S. Karmakar-Mangaj 1 , A. Srivastava 1 , R. Talukdar 1 , S. Nayak 1 , P. Pawar 1 , A. P.S. 1 , J. E.P. 1 , S. Pilakkal 1 , K. Bist 1 , M. Nadkarni 2 , B. Ghugare 2 , S. Goyle 3 , I.N. Shaikh 3 , R. Mistry 2 1 Kokilaben Dhirubhai Ambani hospital and medical research institute , Radiation Oncology, Mumbai, India; 2 Kokilaben Dhirubhai Ambani hospital and medical research institute , Surgical Oncology, Mumbai, India; 3 Kokilaben Dhirubhai Ambani hospital and medical research institute , Medical Oncology, Mumbai, India Purpose or Objective To understand the penetration of Ultra Hypofractionation with five fractions (FAST and FAST FORWARD clinical trial) adjuvant radiotherapy regimen for primary breast cancers in a tertiary centre in India one year post COVID and to evaluate and compare patient characteristics influencing the choice of treatment Materials and Methods All consecutive patients of carcinoma breast treated with curative intent with adjuvant radiotherapy at our institute between 1st April 2019 to 31st March 2020 (Pre-Pandemic) and 1st September 2021 to 31st August 2022 (Post-Pandemic) were included. Patient details were retrieved from database and medical records and treatment details were retrieved from treatment planning system. All patients warranting adjuvant radiation were treated with either 5 fractions or 15 fractions of radiation based on treating clinician’s discretion. Univariable analysis was carried out to identify significant factors influencing treatment schedule with SPSS software© and the factors which had p value of <0.05 were included for multivariable analysis. All Patients were treated on linear accelerator with appropriate immobilisation Results 358 patients and of this 12 had bilateral breast cancer, in total 370 breasts/Chest Walls were treated with adjuvant radiotherapy. Nine patients were excluded due to 25 fractionation schedule and final eligible treatments for the study was 361. Among them, 136 (134 patients) were pre-pandemic and 225 (215 patients) were post pandemic. All the pre-pandemic patients were treated with 15 fractions radiation regimen while 31 among 225 treatment sites in post pandemic cohort were treated with 5 fractions regimen. Patient demographics, Univariable and Multivariable analysis for association of patient characteristics with dose fractionation schedule are depicted on table 1 and table 2, respectively On univariable analysis, patient characteristics influencing the treatment regimen were nodal irradiation status (p=0.00), histology grade (p=0.007), type of surgery (BCS/Mastectomy) (p=0.00), Adjuvant/Neoadjuvant chemotherapy (p=0.00), Early/advanced stage disease at presentation (p=0.00) and Sentinel nodal biopsy/Nodal dissection (p= 0.00). These characteristics were further included for multivariable analysis. Results of the multivariable analysis showed that nodal irradiation status (p=0.00) and histology grade (p=0.005) have significant influence in dictating treatment regimen in adjuvant radiation of breast cancer