Accelerated partial breast irradiation using 3D conformal radiotherapy: Toxicity and cosmetic outcome

作者：Gatti M^*; Ponzone R; Bresciani S; Panaia R; Kubatzki F; Maggiorotto F; Di Virgilio M R; Salatino A; Baiotto B; Montemurro F; Stasi M; Gabriele P

来源：Breast, 2013, 22(6): 1136-1141.

DOI：10.1016/j.breast.2013.07.042

• Partial breast irradiation
• Breast cancer
• Breast-conserving therapy
• Three-dimensional conformal irradiation

Purpose: The aim of this paper is to analyze the incidence of acute and late toxicity and cosmetic outcome in breast cancer patients submitted to breast conserving surgery and three-dimensional conformal radiotherapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI).
Methods and materials: 84 patients were treated with 3D-CRT for APBI. This technique was assessed in patients with low risk stage I breast cancer enrolled from September 2005 to July 2011. The prescribed dose was 34/38.5 Gy delivered in 10 fractions twice daily over 5 consecutive days. Four to five no-coplanar 6 MV beams were used. In all CT scans Gross Tumor Volume (GTV) was defined around the surgical clips. A 1.5 cm margin was added by defining a Clinical Target Volume (CTV). A margin of 1 cm was added to CTV to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the NSABP/RTOG protocol. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed using the Harvard scale.
Results: Median patient age was 66 years (range 51-87). Median follow-up was 36.5 months (range 13 -83). The overall incidence of acute skin toxicities was 46.4% for grade 1 and 1% for grade 2. The incidence of late toxicity was 16.7% for grade 1, 2.4% for grade 2 and 3.6% for grade 3. No grade 4 toxicity was observed. The most pronounced grade 2 late toxicity was telangiectasia, developed in three patients. Cosmetics results were excellent for 52%, good for 42%, fair for 5% and poor for 1% of the patients. There was no statistical correlation between toxicity rates and prescribed doses (p = 0.33) or irradiated volume (p = 0.45).
Conclusions: APBI using 3D-CRT is technically feasible with very low acute and late toxicity. Long-term results are needed to assess its efficacy in reducing the incidence of breast relapse.

• 出版日期2013-12