Dose Sparing Potential of Deep Inspiration Breath-hold Technique for Left Breast Cancer Radiotherapy Organs-at-risk.
To assess if deep inspiration breath-hold (DIBH) technique achieved dose sparing for organs-at-risk in left breast radiotherapy patients in order to reduce long-term complications.



DIBH and Free-breathing (FB) as a control, CT planning scans obtained for 28 left breast/chest wall (+/- supraclavicular field) patients treated January 2008-December 2013 were retrospectively re-contoured and re-planned. Organs-at-risk examined: lungs, left lung, heart and left anterior descending coronary artery (LADCA). Quantitative statistical analysis of plan dose differences was performed.



Lung dose was not affected by DIBH. Heart Dmaxreduced by 34.5% (FB=41.81Gy, SD=3.963Gy vs. DIBH=27.39Gy, SD=12.393Gy, p<0.000004). Heart Dmeanreduced by 32.6% (FB=1.817Gy, SD=0.627Gy vs. DIBH=1.224Gy, SD=0.344Gy, p=0.00000083067. LADCA Dmaxreduced by 47.8% (DIBH mean=15.56Gy, SD=10.62Gy vs. FB mean=29.82Gy, SD=10.05Gy, p=0.000031, and LADCA Dmeanby 52% (DIBH mean=5.23Gy, SD=1.94Gy vs. FB mean=10.88Gy, SD=3.95Gy p=0.000000036027. Amplitude depths were not correlated with dose reductions.



DIBH significantly reduces heart and LADCA dose. Further research is required to evaluate potential long-term implications for patients treated DIBH.
Beacon Hospital, Sandyford, Dublin, Ireland lawlerg@tcd.ie.|Discipline of Radiation Therapy, Trinity College, Dublin, Ireland.
Gavin
G
Lawler
Discipline of Radiation Therapy, Trinity College, Dublin, Ireland.
Michelle
M
Leech
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D062485:Breath Holding; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000528:radiation effects; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008875:Middle Aged; D058958:Organs at Risk / Q000000981:diagnostic imaging / Q000528:radiation effects*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
Breast cancer; cardiac dose; deep inspiration breath-hold; radiotherapy