ESTRO meets Asia 2024 - Abstract Book

S77

Interdisciplinary – Breast

ESTRO meets Asia

using DIBH technique in Ramathibodi Hospital between June 2021 and November 2022. The patient and clinical data were collected from medical records. The heart parameters were measured from AP view CXR. The mean heart dose was recorded from RT treatment planning.

Results:

The 37 patients were included in this study. The |R| values of correlation between heart's parameters from CXR and mean heart dose difference between FB and techniques was ranging from 0.08 to 0.15. Tumor located at inner quadrant area was a statistically significant factor, of which the DIBH technique could reduce the mean heart dose <0.9 Gy when compared to tumor located in outer quadrant area (OR= 0.05, p=0.03). We observed a trend towards mean heart dose reduction <0.9 Gy in the case using tumor bed boost (OR= 0.04, p=0.055). Pathological tumor size ≥2 cm was a factor, showing a trend towards reducing mean heart dose ≥0.9 Gy (OR=14.37, p=0.053).

Conclusion:

The heart's parameters from CXR were not correlated with mean heart dose difference and could not be used to predict the benefit of reducing mean heart dose ≥0.9 Gy between FB and DIBH technique. The inner quadrant tumor was a factor, of which the DIBH technique significantly reduced the mean heart dose to <0.9 Gy when compared to that of outer quadrant tumor. The use of a tumor bed boost showed a trend towards reducing mean heart dose to <0.9 Gy. In contrast, pathological tumor size ≥2 cm showed a trend towards reducing mean heart dose to ≥0.9 Gy. However, additional data are needed to enhance the robustness of this study.

Keywords: DIBH, chest X-rays, mean heart dose

References:

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