Moderate deep inspiration breath-hold reduces cardiac and lung irradiation during left-sided breast cancer treatment

Moderate deep inspiration breath-hold (mDIBH) using an active breathing control (ABC) device reduces cardiac irradiation during left-sided breast cancer treatment, reported Todd A. Swanson, MD, PhD, William Beaumont Hospital, Royal Oak, Michigan, at the 2009 ASCO Breast Cancer Symposium during a poster discussion. He noted that this technique has been used in his clinic since 2002 and that its use has been expanded to routinely include patients with early stage and locally advanced breast cancer who receive treatment to an intact breast, reconstructed breast, or the chest wall along with draining lymphatics, in some cases.

Over a period of 6 years, the investigators evaluated 100 patients with stage 0 to stage III left-sided breast cancer for ABC treatment. Of these patients, 87 were determined to be candidates for this treatment. The investigators compared treatment plans for both free-breathing (FB) and mDIBH, assessing dose volume parameters for the heart, ipsilateral lung, and both lungs.

Of the 87 patients included in the study, 66% received adjuvant chemotherapy with cardiotoxic agents, 45% with anthracycline-based regimens and 9% with trastuzumab. The mean dose to the whole breast was 47.6 Gy, and 89% received a mean boost dose of 12 Gy. There was a statistically significant decrease in all normal tissue dosimetric parameters using mDIBH compared with FB. Further, the mDIBH technique significantly reduced the cardiac mean dose from 4.23 Gy observed with FB to 2.54 Gy (P <.001) as well as heart V30 (volume of heart receiving > 30 Gy), V25, V20, V15, V10, and V5. For 34% of patients, the heart V25 was 0% when mDIBH was used. The radiation dose delivered to the lungs was also reduced, including a reduction of the left lung mean dose from 9.08 Gy with FB to 7.86 Gy with mDIBH (P <.001).

This 6-year study represents the largest experience using mDIBH to reduce cardiac irradiation during left-sided breast cancer treatment, and the investigators noted that “the routine integration of ABC using mDIBH is a proven technique for reduction in cardiac dose that may lead to reduced cardiotoxicity.” According to Lori Pierce, MD, professor of radiation oncology, University of Michigan School of Medicine, Ann Arbor, who commented on these findings in a press statement, “this treatment planning study illustrates a technique that can be used to decrease radiation exposure to the heart and lungs,” noting “it highlights an example of individualized treatment planning that can be implemented for our patients to further improve the risk benefit ratio for the safe delivery of radiation.”

Dr Swanson was a recipient of the 2009 Breast Cancer Symposium Merit Awards.

Abstract 223