Journal article

Quantification of the geometric uncertainty when using implanted markers as a surrogate for lung tumor motion

Nicholas Hardcastle, Adam Briggs, Vincent Caillet, Giorgios Angelis, Danielle Chrystall, Dasantha Jayamanne, Meegan Shepherd, Ben Harris, Carol Haddad, Thomas Eade, Paul Keall, Jeremy Booth

Medical Physics | WILEY | Published : 2021


BACKGROUND: Fiducial markers are used as surrogates for tumor location during radiation therapy treatment. Developments in lung fiducial marker and implantation technology have provided a means to insert markers endobronchially for tracking of lung tumors. This study quantifies the surrogacy uncertainty (SU) when using endobronchially implanted markers as a surrogate for lung tumor position. METHODS: We evaluated SU for 17 patients treated in a prospective electromagnetic-guided MLC tracking trial. Tumor and markers were segmented on all phases of treatment planning 4DCTs and all frames of pretreatment kilovoltage fluoroscopy acquired from lateral and frontal views. The difference in tumor a..

View full abstract


Funding Acknowledgements

The authors thank the patients who enrolled in the LIGHT SABR clinical trial and the team of people involved in acquiring the large amount of data used in the present study. JTB acknowledges support for LIGHT SABR clinical study by a Varian Medical Systems Collaborative Research Grant.