The dosimetric benefit of in‐advance respiratory training for deep inspiration breath holding is realized during daily treatment in left breast radiotherapy: A comparative retrospective study of serial surface motion tracking

Abstract

Introduction A novel approach of in‐advance preparatory respiratory training and practice for deep inspiration breath holding (DIBH) has been shown to further reduce cardiac dose in breast cancer radiotherapy patients, enabled by deeper (extended) DIBH. Here we investigated the consistency and stability of such training‐induced extended DIBH after training completion and throughout the daily radiotherapy course. Methods Daily chestwall motion from real‐time surface tracking transponder data was analysed in 67 left breast radiotherapy patients treated in DIBH. Twenty‐seven received preparatory DIBH training/practice ( prep Trn) 1–2 weeks prior to CT simulation, resulting in an extended DIBH ( ext DIBH) and reduced cardiac dose at simulation. Forty had only conventional immediate pre‐procedure DIBH instruction without prep Trn and without extended DIBH (non‐Trn group). Day‐to‐day variability in chestwall excursion pattern during radiotherapy was compared among the groups. Results The average of daily maximum chestwall excursions was overall similar, 2.5 ± 0.6 mm for prep Trn/ ext DIBH vs. 2.9 ± 0.8 mm for non‐Trn patients ( P = 0.24). Chestwall excursions beyond the 3‐mm tolerance threshold were less common in the prep Trn/ ext DIBH group (18.8% vs. 37.5% of all fractions within the respective groups, P = 0.038). Among patients with cardiopulmonary disease those with prep Trn/ ext DIBH had fewer chestwall excursions beyond 3 mm (9.4% vs. 46.7%, P = 0.023) and smaller average maximum excursions than non‐Trn patients (2.4 ± 0.3 vs. 3.0 ± 0.6 mm, P = 0.047, respectively). Conclusion Similar stability of daily DIBH among patients with and without preparatory training/practice suggests that the training‐induced extended DIBH and cardiac dose reductions were effectively sustained throughout the radiotherapy course. Training further reduced beyond‐tolerance chestwall excursions, particularly in patients with cardiopulmonary disease.

Heart Sparing Radiotherapy Techniques in Breast Cancer: A Focus on Deep Inspiration Breath Hold

“…48 Therefore, it is important to deploy DIBH techniques on a case-by-case basis, keeping in mind a patient's ability to tolerate the technique, the cost, patient convenience, tumor characteristics (ie, laterality, size, location, histology), and whether the patient may benefit from in-advance respiratory training. [80][81][82] Regardless of the technique used, DIBH results in a longer simulation and treatment time compared to free breathing, and patients should be able to lie comfortably in the supine or prone position for the duration of the therapy delivery.…”

“…16 In addition to the cardiac benefits of DIBH in right-sided breast cancer patients, there can also be a decline in the dose to the ipsilateral lung and liver. [79][80][81][82][83] Therefore, patients with right-sided disease who have pre-existing conditions necessitating the lowest feasible dose to either the lungs or liver, and those whose plan include the IMC lymph nodes, should be considered for DIBH in addition to those with left-sided disease.…”

Setup margins based on the inter‐ and intrafractional setup error of left‐sided breast cancer radiotherapy using deep inspiration breath‐hold technique (DIBH) and surface guided radiotherapy (SGRT)

“…While excellent intrafractional setup accuracy has in general been reported during DIBH using SGRT, greater deviations have also been observed. 3 , 4 Many workflow and patient‐related factors may impact the patient positioning accuracy; for example, the DIBH technique used (voluntary, spirometry, x‐ray, infrared markers), 5 the gating protocol (threshold value, automatic, or manual gating), the use of a visual feedback system for the patient to monitor the correct thorax position during DIBH, 6 , 7 conducting a pre‐treatment training for DIBH, 8 the patient compliance, the thorax shape, 9 , 10 , 11 and other factors. The patients in our analysis were positioned for radiotherapy using daily SGRT and kilovolt cone‐beam computed tomography scans (kV‐CBCT).…”