B. Raouia (Ariana, Tunisia)
Author Of 1 Presentation
85P - Hypofrationated Radiotherapy for Breast Cancer: Does obesity increase the skin toxicity?
Abstract
Background
We aimed to assess correlation between radiation fractionation schedule, body mass index (BMI) and acute skin toxicity in post-operative hypofractionated radiotherapy for breast cancer.
Methods
We retrospectively evaluated 102 breast cancer patients treated with 3-dimensional conformal radiotherapy after breast conserving surgery between August 2017 and December 2019. The prescribed dose was 40.05 Gy in 15 fractions to the whole breast followed by 13.35 Gy in 5 fractions to tumor bed. BMI was categorized as underweight –normal (BMI ≤ 27) and overweight-obese (BMI > 27). Breast volume was measured manually by contouring of the breast target volume on the planning CT scan. All patients were monitored for acute skin toxicity during radiotherapy according to CTCAE v4.0 (common toxicity criteria for adverse events) scale. The correlation between the incidence of skin toxicity and its grading with BMI and breast volume was performed with the χ2 test.
Results
The median BMI was 30 kg/m2 (19-45) and the median breast volume was 693.80 cc (100-2777cc). Acute G2-3 skin toxicity was significantly higher for patients with BMI > 27 than those with BMI ≤ 27 (37% vs 15% p=0.04). The mean CTV volume of patients experiencing G2-3 erythema was significantly higher than that of patients with G0-1 erythema (1005.3cc vs 731.3cc respectively [P=0.000]). Among those with a breast volume >800 cc, G2-3 skin toxicity occurred in 42% compared with 17.4% in patients with breast volume ≤800cc. Combination of a high BMI (>27) and a breast volume>800cc was associated with an increased risk of G2-3 skin toxicity (60.7% vs 39.3% in case of BMI> 27 or breast volume > 800cc [p=0.003]).
Conclusions
BMI and breast volume were correlated with higher risk of acute skin toxicity after postoperative breast hypofractionated radiotherapy but no G4 toxicity was observed. Hypofractionated schedule was not associated with severe toxicity and could be considered for this population.
Legal entity responsible for the study
Pr Lotfi Kochbati.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.
Presenter Of 1 Presentation
85P - Hypofrationated Radiotherapy for Breast Cancer: Does obesity increase the skin toxicity?
Abstract
Background
We aimed to assess correlation between radiation fractionation schedule, body mass index (BMI) and acute skin toxicity in post-operative hypofractionated radiotherapy for breast cancer.
Methods
We retrospectively evaluated 102 breast cancer patients treated with 3-dimensional conformal radiotherapy after breast conserving surgery between August 2017 and December 2019. The prescribed dose was 40.05 Gy in 15 fractions to the whole breast followed by 13.35 Gy in 5 fractions to tumor bed. BMI was categorized as underweight –normal (BMI ≤ 27) and overweight-obese (BMI > 27). Breast volume was measured manually by contouring of the breast target volume on the planning CT scan. All patients were monitored for acute skin toxicity during radiotherapy according to CTCAE v4.0 (common toxicity criteria for adverse events) scale. The correlation between the incidence of skin toxicity and its grading with BMI and breast volume was performed with the χ2 test.
Results
The median BMI was 30 kg/m2 (19-45) and the median breast volume was 693.80 cc (100-2777cc). Acute G2-3 skin toxicity was significantly higher for patients with BMI > 27 than those with BMI ≤ 27 (37% vs 15% p=0.04). The mean CTV volume of patients experiencing G2-3 erythema was significantly higher than that of patients with G0-1 erythema (1005.3cc vs 731.3cc respectively [P=0.000]). Among those with a breast volume >800 cc, G2-3 skin toxicity occurred in 42% compared with 17.4% in patients with breast volume ≤800cc. Combination of a high BMI (>27) and a breast volume>800cc was associated with an increased risk of G2-3 skin toxicity (60.7% vs 39.3% in case of BMI> 27 or breast volume > 800cc [p=0.003]).
Conclusions
BMI and breast volume were correlated with higher risk of acute skin toxicity after postoperative breast hypofractionated radiotherapy but no G4 toxicity was observed. Hypofractionated schedule was not associated with severe toxicity and could be considered for this population.
Legal entity responsible for the study
Pr Lotfi Kochbati.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.