ESTRO 2024 - Abstract Book

S681

Clinical - Breast

ESTRO 2024

MHD for natural-DIBH vs. FB: 5.2 mm, for ultimate-DIBH vs. FB: 7.6 mm, for natural-DIBH vs. ultimate-DIBH: 2.3 mm. The mean difference of left lung volume for these comparisons are shown in Table 1. All these differences are statistically significant (p-value<0.05). Their p-values are listed in Table 1.

Table 1. The mean difference of MHD, left and right lung volumes for the comparisons of the three breathing modes.

MHD (cm) p-value Vol_Lung_L (cm3)

p-value Vol_Lung_R (cm3) p-value

FB vs.

natural-DIBH

0.52

<0.01

-621.73

<0.01

-30.93

0.63

FB vs.

ultimate-DIBH 0.76

<0.01

-825.56

<0.01

-800.49

0.06

natural-DIBH vs.

ultimate-DIBH 0.23

0.02

-203.83

0.01

-769.56

0.06

Conclusion:

We found most patients (over 70%) could comply with ultimate-DIBH under proper coaching. The ultimate-DIBH showed smaller mean in-field heart distance and larger mean lung volume compared to natural-DIBH. This will lead to reduced cardiac and lung dose exposure.

Keywords: Personalized breathing method, DIBH, cardiac dose

References:

1. Darby, S.C., et al., Risk of ischemic heart disease in women after radiotherapy for breast cancer. The New England journal of medicine, 2013. 368(11): p. 987-98.

2. Nissen, H.D. and A.L. Appelt, Improved heart, lung and target dose with deep inspiration breath hold in a large clinical series of breast cancer patients. Radiother Oncol, 2013. 106(1): p. 28-32.

3. Mohamad, O., et al., Deep inspiration breathhold for left-sided breast cancer patients with unfavorable cardiac anatomy requiring internal mammary nodal irradiation. Practical Radiation Oncology, 2017. 7(6): p. e361 e367.