TITLE:
A Longitudinal Study of Clinical Benefits with Implementation of the Deep Inspiration Breath-Hold Technique in Post-Operative Radiotherapy for Left-Sided Breast Cancer
AUTHORS:
Chunhui Han, Nayana Vora, Sean Zhang, An Liu, Jeffrey Y. C. Wong
KEYWORDS:
Breast Cancer, Heart Toxicity, Breath Hold, Extern-Beam Radiotherapy
JOURNAL NAME:
International Journal of Medical Physics, Clinical Engineering and Radiation Oncology,
Vol.8 No.3,
August
28,
2019
ABSTRACT:
Purpose/Objectives: We aimed to report clinical effects on critical organ dose
and cardiac toxicity from implementation of the deep inspiration breath-hold
(DIBH) technique in post-operative extern-beam radiotherapy of patients with
left-sided breast cancer, using longitudinal clinical data. Materials/Methods:
We retrieved three groups of patients who received post-operative radiotherapy
of left-sided breast cancer in our institution in recent years: Groups A and
B consist of patients whose treatment did not include internal mammary
nodes (IMN) and who were treated with the free breathing technique and
with the DIBH technique, respectively, and Group C consists of patients
whose radiotherapy included internal mammary nodes with the DIBH technique.
Dose parameters for the heart and left lung were retrieved from the
treatment plans. Radiation-induced cardiac risks were estimated using existing
risk models. Results: The average heart dose was 2.65 ± 0.98 Gy, 1.10 ±
0.29 Gy, and 1.26 ± 0.25 Gy in Groups A, B, and C, respectively. The average
heart volumes receiving at least 25 Gy were 7.10 ± 9.79 cc in Group A, 0.07 ±
0.22 cc in Group B, and 0.03 ± 0.08 cc in Group C. On average, the excessive
risk of having ischemic heart disease was estimated to be 19.6%, 8.1%, and
9.3% in Groups A, B, and C, respectively. The mean left lung doses were 5.73
± 1.86 Gy, 5.93 ± 1.55 Gy, and 9.13 ± 1.57 Gy in Groups A, B, and C, respectively. Conclusion: Implementation of the DIBH technique significantly lowered
heart dose and decreased the ischemic heart disease risk in patients receiving
post-operative radiotherapy for left-sided breast cancer, without significant
increase in left lung dose.