Abstract
Radiation therapy with respiratory gating has typically been used in the treatment of lung tumours. This technique offers clinical advantages when applied to other sites as well. This is a case report of a 47-year-old woman who presented with a localized recurrent breast cancer in the left 6th intercostal space and declined a chest wall resection. Standard radiation therapy carried a significant risk of cardiac toxicity. A respiratory gated, deep inspiration breath-hold technique (DIBH) was developed that significantly reduced the dose to her heart and ipsilateral lung while delivering a curative dose (70 Gy) to the recurrent tumour. Treatment accuracy, setup, reproducibility, and daily treatment times were measured. DIBH was tolerable, reproducible, and, after the first week, could be delivered within a 15-minute treatment slot. Toxicity was minimal.