Active Breathing Coordinator-based vs VisionRT-based Deep Inspiration Breath-hold for Radiation for Breast Cancer

Female patients treated with radiation for left-sided breast malignancy will undergo
alternate fractions of ABC-assisted and VisionRT-assisted DIBH. Residual motion during
breath-hold will be quantitatively assessed using MV fluoroscopy from the treatment beam
itself (i.e., no additional radiation dose). The dosimetric impact of residual motion on
organs at risk (heart and lung) will be assessed by applying rigid and/or deformable
displacements to the planning CT images, computing the 3D dose map and comparing with the
original planned dose map.

Inclusion Criteria:

- Women with diagnosis of breast malignancy

- Women whom requires left chest wall post-mastectomy radiation with or without bolus

- Age ≥ 18 years.

- Performance status ECOG
- Women of child-bearing potential must agree to use adequate contraception (hormonal or
barrier method of birth control; abstinence) prior to study entry, for the duration of
study participation, and for 90 days following completion of therapy. Should a woman
become pregnant or suspect she is pregnant while participating in this study, she
should inform her treating physician immediately Ability to understand and the
willingness to sign a written informed consent.

- Patient must be able to maintain a 30 second breath hold.

- Conventional chest wall radiation delivery dose of 50.4 Gy/ 28 fractions with or
without a boost (boost will not be evaluated for endpoints)

Exclusion Criteria:

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements.

- Subjects must not be pregnant or nursing due to the potential for congenital
abnormalities and the potential of this regimen to harm nursing infants.