Resource requirements and reduction in cardiac mortality from deep inspiration breath hold (DIBH) radiation therapy for left sided breast cancer patients: A prospective service development analysis.

INTRODUCTION: Use of deep inspiration breath hold (DIBH) radiation therapy may reduce long-term cardiac mortality. The resource and time commitments associated with DIBH are impediments to its widespread adoption. We report the dosimetric benefits, workforce requirements, and potential reduction in cardiac mortality when DIBH is used for left-sided breast cancers. METHODS AND MATERIALS: Data regarding the time consumed for planning and treating 50 patients with left-sided breast cancer with DIBH and 20 patients treated with free breathing (FB) radiation therapy were compiled prospectively for all personnel (regarding person-hours [PH]). A second plan was generated for all DIBH patients in the FB planning scan, which was then compared with the DIBH plan. Mortality reduction from use of DIBH was calculated using the years of life lost resulting from ischemic heart disease for Indians and the postulated reduction in risk of major cardiac events resulting from reduced cardiac dose.
RESULTS: The median reduction in mean heart dose between the DIBH and FB plans was 166.7 cGy (interquartile range, 62.7-257.4). An extra 6.76 PH were required when implementing DIBH as compared with FB treatments. Approximately 3.57 PH were necessary per Gy of reduction in mean heart dose. The excess years of life lost from ischemic heart disease if DIBH was not done in was 0.95 per 100 patients, which translates into a saving of 12.8 hours of life saved per PH of work required for implementing DIBH. DIBH was cost effective with cost for implementation of DIBH for all left-sided breast cancers at 2.3 times the annual per capita gross domestic product.
CONCLUSION: Although routine implementation of DIBH requires significant resource commitments, it seems to be worthwhile regarding the projected reductions in cardiac mortality.