2023 World Conference on Lung Cancer (Posters)-EP08.02. Optimal Planning Target Volume Margins for Spirometer-Based DIBH Radiotherapy for Lung Cancer

EP08.02. Optimal Planning Target Volume Margins for Spirometer-Based DIBH Radiotherapy for Lung Cancer - PDF(Abstract)

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This study presented the optimal planning target volume (PTV) margins for spirometer-based deep-inspiration breath-hold (DIBH) radiotherapy for lung cancer. The aim was to estimate lobe-specific margins for the PTV in patients with lung cancer undergoing spirometer-based DIBH radiotherapy. Ten patients were enrolled in the study, and two spirometer-based DIBH CT scans were performed during the treatment period. Bronchial bifurcation points were manually defined, and PTV margins were estimated using two setup scenarios: vertebral body matching and carina matching. <br /><br />The results showed that the estimated PTV margins varied depending on the scenario and direction. In the vertebral body matching scenario, the PTV margins ranged from 0.1 to 3.0 mm in the right-left direction, 0.3 to 4.3 mm in the anterior-posterior direction, and 0.2 to 4.6 mm in the superior-inferior direction. In the carina matching scenario, the PTV margins ranged from 0.0 to 2.7 mm in the right-left direction, 0.1 to 3.6 mm in the anterior-posterior direction, and 0.0 to 5.2 mm in the superior-inferior direction. <br /><br />Overall, the reproducibility of the spirometer-based DIBH technique was found to be acceptable in both setup scenarios. However, tumors located in the left anteromedial-lateral-posterior segment required a PTV margin of at least 5 mm in the superior-inferior direction in the carina matching scenario. <br /><br />In conclusion, this study provides valuable information on the optimal PTV margins for spirometer-based DIBH radiotherapy in patients with lung cancer. These findings can aid radiation oncologists in planning and delivering more precise and effective radiotherapy treatments for lung cancer.

Asset Subtitle

Noriko Kishi

Meta Tag

Speaker Noriko Kishi

Topic Local-Regional NSCLC: Multimodality Therapy

Keywords

optimal planning target volume

PTV margins

spirometer-based deep-inspiration breath-hold

DIBH radiotherapy

lung cancer

lobe-specific margins

vertebral body matching

carina matching

reproducibility

radiation oncologists