An effective deep-inspiration breath-hold radiotherapy technique for left-breast cancer: impact of post-mastectomy treatment, nodal coverage, and dose schedule on organs at risk

Abstract

BackgroundWe developed, applied, and prospectively evaluated a novel deep-inspiration breath-hold (DIBH) screening and delivery technique to optimize cardiac sparing in left-breast radiotherapy (RT) at our clinic. The impact of set-up and dose variables upon organs at risk (OAR) dose in DIBH RT was investigated.Methods and materialsAll patients with left-breast cancer referred between 2011 and 2014 – of all disease stages, set-up variations, and dose prescriptions – were included. Radiographers used simple screening criteria at CT simulation, to systematically assess patients for obvious DIBH benefit and capability. Selected patients received forward-planned intensity-modulated RT (IMRT) based on a DIBH CT scan. A 3D-surface monitoring system with visual feedback assured reproducible DIBH positioning during gated radiation delivery. Patient, target set-up, and OAR dose information were collected at treatment.ResultsOf 272 patients who were screened, 4 withdrew, 56 showed no obvious advantage, and 56 showed benefit but had suitability issues; 156 patients were selected and successfully completed DIBH treatment. The technique was compatible with complex set-up and optimal target coverage was maintained. Comparison of free-breathing (FB) and DIBH treatment plans in the first five patients enrolled confirmed DIBH reduced heart radiation by ~80% (p = 0.032). Low OAR doses were achieved overall: the mean (95% confidence interval [CI]) heart dose was 1.17 (1.12–1.22) Gy, and the mean ipsilateral lung dose was 5.26 (5.01–5.52) Gy. Patients who underwent a standard radiation schedule (40 Gy/15#) after breast-conserving surgery had the lowest OAR doses: post-mastectomy treatment, simultaneous supraclavicular (SCV) node coverage, and alternative dose schedule (50 Gy/25#) were interrelated variables associated with increased OAR risk and compromised ipsilateral lung dose constraints.ConclusionThe DIBH technique was successfully implemented and resulted in optimally low heart radiation. All patients who demonstrate sufficient DIBH technique at planning CT are now offered DIBH RT at our clinic. Patients with more advanced disease, particularly those with additional pulmonary risk factors, warrant additional focus to improve lung sparing.

Evaluation of the heart and lung dosimetric parameters in deep inspiration breath hold using 3D Slicer

“…The results of the present study demonstrated the ability of DIBH in the reduction of the heart dose in patients with left-sided breast cancer as reported in previous studies [7][8][9][10][11][12]. However, similar to some reports, the collected data of the present study did not show the protective effect of this technique on the left lung [8,[15][16][17][18][19][20]. In the present study, the average of the heart D mean and Values are presented as mean ± standard deviation.…”

“…Although this technique reduces the heart dose [7][8][9][10][11][12], it seems that there are challenges in the reduction of lung dose with DIBH [13]. Despite the results of many studies showing the reduction of the ipsilateral lung dose [2,7,11,14], there are reports of no significant difference and even increasing the left lung dosimetric parameters using DIBH [8,[15][16][17][18][19][20].…”

Real-time intra-fraction motion management in breast cancer radiotherapy: analysis of 2028 treatment sessions

“…Patients who received RT in deep inspiration breath hold (DIBH) were excluded from the present analysis. [14,15] The study was approved by the local ethics committee of the University Hospital, LMU Munich (No. 352-16 ex 09/2016) and registered at German Clinical Trials Register (DRKS-ID: DRKS00011407).…”

The potential benefits from respiratory gating for breast cancer patients regarding target coverage and dose to organs at risk when applying strict dose limits to the heart: results from the DBCG HYPO trial

“…There has been quite some interest on reducing the dose to the left anterior descending coronary artery (LADCA) since reports have indicated an association between LADCA irradiation and the risk of ischemic heart disease [13][14][15]. In order to optimize target coverage while maintaining a low dose to OAR, techniques for RT with respiratory gating (RG), like enhanced inspiration gating and deep-inspiration breath hold (DIBH), have successfully been implemented in RT centres during the last decade [16][17][18][19]. These techniques exploit that during a deep inspiration the heart shifts in caudal and dorsal direction compared to the breast, moving the heart away from the high dose region of typical tangential fields.…”