2024 World Conference on Lung Cancer (WCLC) - ePosters-EP.07F.06 Prospective Study of Breath Hold During SBRT Treatment of the Lung: Analysis Reliability of Surface Guidance Alone for Breath Hold

EP.07F.06 Prospective Study of Breath Hold During SBRT Treatment of the Lung: Analysis Reliability of Surface Guidance Alone for Breath Hold

Back to course

Pdf Summary

The study investigates the reliability of surface-guided radiation therapy (SGRT) for breath hold (BH) stereotactic body radiation therapy (SBRT) treatments in patients with primary non-small cell lung cancer (NSCLC) or lung metastases. This IRB-approved prospective study involved patients who exhibited at least 1 cm of respiratory motion during free-breathing as determined by 4DCT. Patients were treated with SBRT while holding their breath to minimize dosage to normal lung tissues. Alignments were based on a breath hold reference from a planning CT, and treatments adhered to strict position tolerances.<br /><br />SGRT uses non-ionizing 3D stereoscopic cameras to track patient surface, previously utilized in larger targets like breast cancer, but not assessed for small targets such as lung tumors. During treatment, alignment was checked mid-treatment using short-arc cone beam CT (CBCT) for target position verification. The study employed linear mixed models to assess translational and rotational shifts.<br /><br />A total of 21 patients participated, undergoing 63 SBRT fractions, with most receiving 54 Gy in three fractions, and one patient receiving 50 Gy in five fractions for a central tumor. The median range of motion was 1.5 cm. According to the results, mean displacements were minimal across all directions. Only one instance observed exceeded the 5 mm planning target volume expansion. Variables like age, BMI, gender, tumor location, and range of motion did not correlate with increased shift magnitudes.<br /><br />The study concludes that SGRT is a reliable technique for monitoring BH during SBRT for lung treatments, showing minimal target displacements during therapy. The study notes further monitoring for toxicity and local control, with comparisons to free-breathing SBRT to follow in upcoming analyses.

Asset Subtitle

John Heinzerling

Meta Tag

Speaker John Heinzerling

Topic Early-Stage Non-small Cell Lung Cancer

Keywords

surface-guided radiation therapy

breath hold

stereotactic body radiation therapy

non-small cell lung cancer

lung metastases

4DCT

cone beam CT

translational shifts

rotational shifts

target displacements