The UK HeartSpare Study: Randomised evaluation of voluntary deep-inspiratory breath-hold in women undergoing breast radiotherapy

Purpose: To determine whether voluntary deep-inspiratory breath-hold (v_DIBH) and deep-inspiratory breath-hold with the active breathing coordinator (TM) (ABC_DIBH) in patients undergoing left breast radiotherapy are comparable in terms of normal-tissue sparing, positional reproducibility and feasibility of delivery. Methods: Following surgery for early breast cancer, patients underwent planning-CT scans in v_DIBH and ABC_DIBH. Patients were randomised to receive one technique for fractions 1-7 and the second technique for fractions 8-15 (40 Gy/15 fractions total). Daily electronic portal imaging (EPI) was performed and matched to digitally-reconstructed radiographs. Cone-beam CT (CBCT) images were acquired for 6/15 fractions and matched to planning-CT data. Population systematic (Sigma) and random errors (sigma) were estimated. Heart, left-anterior-descending coronary artery, and lung doses were calculated. Patient comfort, radiographer satisfaction and scanning/treatment times were recorded. Within-patient comparisons between the two techniques used the paired t-test or Wilcoxon signed-rank test. Results: Twenty-three patients were recruited. All completed treatment with both techniques. EPI-derived Sigma were <= 1.8 mm (v_DIBH) and <= 2.0 mm (ABC_DIBH) and sigma <= 2.5 mm (v_DIBH) and <= 2.2 mm (ABC_DIBH) (all p non-significant). CBCT-derived Sigma were <= 3.9 mm (v_DIBH) and <= 4.9 mm (ABC_DIBH) and sigma <= 4.1 mm (v_DIBH) and <= 3.8 mm (ABC_DIBH). There was no significant difference between techniques in terms of normal-tissue doses (all p non-significant). Patients and radiographers preferred v_DIBH (p = 0.007, p = 0.03, respectively). Scanning/treatment setup times were shorter for v_DIBH (p = 0.02, p = 0.04, respectively). Conclusions: v_DIBH and ABC_DIBH are comparable in terms of positional reproducibility and normal tissue sparing. v_DIBH is preferred by patients and radiographers, takes less time to deliver, and is cheaper than ABC_DIBH. (C) 2013 Elsevier Ireland Ltd. All rights reserved.