3013 - Using Two Complemental Deep Inspirational Breath-Hold Techniques to Improve Treatment Accuracy for Patients with Breast Cancer

03:00pm - 04:00pm PT

Hall F

Screen: 18

POSTER

Presenter(s)

Ping Xia, PhD - Cleveland Clinic, Cleveland, OH

B. Faught¹, D. McCarthy¹, C. S. Shah², R. D. Tendulkar², S. Cherian², P. Pendyala³, and P. Xia²; ¹Cleveland Clinic, Cleveland, OH, ²Department of Radiation Oncology, Cleveland Clinic Foundation, Cleveland, OH, ³Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH

Purpose/Objective(s): Deep inspirational breath-hold (DIBH) treatment for patients with left-side breast cancer is a standard practice. DIBH can be achieved by a surrogate either using a surface-based or spirometry-based technique. Each technique has its limitations. Surface-based BH can be influenced by patients arching body. Spirometry-based BH can be influenced by non-compliance. The purpose of this study is to investigate whether using these two complementary methods together can identify non-compliant BHs and improve treatment accuracy.

Materials/Methods:

Thirty-two patients were included in this study and were treated with VMAT plans with DIBH using an active breath-control system to either the partial breast (30 Gy/5 fractions or 45 Gy/30 fractions BID) or whole breast with regional nodes (40 Gy/15 fractions). Prior to each treatment, the treatment position was setup under guidance of a surface-guidance system (SGRT) and verified using a kilo-voltage cone beam CT (CBCT). After applying positional shifts according to CBCT imaging guidance, a new surface reference was captured and used to identify potential non-compliant BHs (NCBH) during treatment. The tolerance for NCBH was set to 3 mm magnitude in the SGRT system. Once NCBH was detected, the first action was patient coaching as follows: (1) not arch the back; (2) adjust their breath depth. If the first action was unsuccessful, the next action was to stop the treatment, acquire a new CBCT, and adjust the patient position.

Results: Among 32 patients, 245 treatment sessions were recorded. In 37 (15%) sessions, NCBH were detected by the SGRT system and 2 (0.8%) sessions required repositioning and reimaging after unsuccessful first action. Across 245 sessions, the average magnitude of NCBH was 5.3 ± 1.7 mm with a maximum of 10.6 mm.

Conclusion:

Most non-compliant BHs can be resolved by additional patient coaching. Using two complementary methods to detect non-compliant BH can improve treatment accuracy.