Program Information
Actual Benefits On Critical Organ Sparing and Complication Reduction with Implementation of the Deep Inspiration Breath-Hold Technique in Radiotherapy of Left Breast Cancer
C Han*, S Zhang , T Schultheiss , J Wong , City of Hope Medical Center, Duarte, CA
Presentations
TH-EF-FS1-3 (Thursday, August 3, 2017) 1:00 PM - 3:00 PM Room: Four Seasons 1
Purpose: We aim to report on quantitative benefits of implementing the deep inspiration breath-hold (DIBH) technique in post-operative radiotherapy of left breast cancer patients in terms of critical organ dose reduction and potential complication reduction, using large historical data from a single institution.
Methods: We retrieved all the patients who received post-operative radiotherapy of left-sided breast cancer in our institution in recent six years, and separated them into two groups: Group A (104 patients) consists of patients who received treatments in the three years before the DIBH technique was implemented in clinical practice, and Group B (170 patients) consists of patients who received radiotherapy with the DIBH technique in the following three years. A patient was included in the study if the prescription dose was 50 – 50.4 Gy with 1.8 or 2 Gy per fraction using two tangential photon beams, with the heart and left lung contoured during treatment planning. Organ dose parameters were retrieved from the treatment plans. Radiation-induced cardiac risks were estimated using published risk models.
Results: The average heart dose was 2.67±0.99 Gy and 1.29±0.53 Gy in Groups A and B, respectively, with statistically significant difference (two-tailed p-value < 0.01). The heart volumes receiving at least 25 Gy were also significantly different between the two groups: averaging 1.32±1.66% (7.41±9.79 cc) in Group A and 0.15±0.38% (0.65±1.53 cc) in Group B. The mean lung doses in Groups A and B were 5.59 cGy and 6.17 Gy, respectively (two-tailed p-value = 0.04). The average excessive risk of having ischemic heart diseases in Group B was estimated to be 9.6% compared to 19.8% in Group A.
Conclusion: Based on historical clinical data, implementation of the DIBH technique could significantly spare heart dose, and lower the ischemic heart disease risk in patients receiving post-operative radiotherapy for left breast cancer.
Contact Email: