ESTRO 2024 - Abstract Book

S709

Clinical - Breast

ESTRO 2024

Ultra-hypofractionated radiotherapy (uHFRT) is emerging as a new standard of care in early breast cancer. Majority of the patients treated in randomised trials received only whole breast radiotherapy as very few women were eligible for tumor bed boost. Hence the impact of uHFRT on cosmetic outcome in women receiving tumor bed boost is largely unknown. In this study we evaluated the 2-year incidence of worsening of cosmesis in a cohort of women treated with ultra-hypofractionated whole breast radiation with tumor bed boost. A comprehensive evaluation of cosmesis was carried out in a prospective cohort of patients that were accrued in an ongoing study at our centre (CTRI/2020/01/022871).

Material/Methods:

All patients (N=207) had received whole breast radiotherapy using one of the five fraction regimens (FAST-F or FAST). Tumor bed boost was offered concurrently either using electrons (N=123) or photons (N=84). Half of the women were postmenopausal while 44% women had left sided tumors. Majority of the women were treated with FAST-F regimen (74.3%) and remaining (25.7%) with FAST regimen. Patients visited clinics for regular follow up every 6 months. Toxicity and cosmesis data was collected at each visit along with breast photographs. The rating of cosmesis was done on 4-point scale: excellent (E), good (G), fair (F) and poor (P). Both subjective (by physician and patient) and objective evaluation (using BCCT.core software) was carried out. Worsening was defined as switching of the rating from EG to FP category. We analyzed the incidence of worsening of cosmesis and the factors corelating with worsening of cosmesis by both subjective and objective methods. We also studied the correlation of cosmesis at last follow up with the body image scale of the EORTC BR 23 (BRBI) quality of life instrument. The negative difference between 2 year BRBI score and baseline BRBI score were considered as worsening whereas a difference of 0 and positive were considered no worsening.

Results:

The median follow-up of the study cohort was 22 months (18-30 months). The incidence of worsening at 2 years compared to baseline in the overall cohort and the two groups of radiotherapy technique has been shown in Table 1. The worsening was reported more often by physician compared to patient.

Physician rating (%)

Patient rating (%)

Objective rating (%)

Overall cohort

Overall cohort

Overall cohort

2-yr worsening rate

26.2

13.5

30.9

3DCRT (Electron boost)*

3DCRT (Electron boost)*

3DCRT (Electron boost)*

2-yr worsening rate

22.7

10.6

28.0

IMRT (Photon boost)*

IMRT (Photon boost)*

IMRT (Photon boost)*

2-yr worsening rate

31.3

17.9

34.6

*All comparisons between 3DCRT & IMRT NS for each assessment (subjective & objective)