Abstract

PurposeTo investigate scanned-beam proton dose distribution reproducibility in the lung under high frequency jet ventilation (HFJV). Materials and methodsFor 11 patients (12 lesions), treated with single-fraction photon stereotactic radiosurgery under HFJV, scanned-beam proton plans were prepared with the TRiP98 treatment planning system using 2, 3–4 and 5–7 beams. The planning objective was to deliver at least 95% of the prescription of 33Gy (RBE) to 98% of the PTV. Plans were subsequently recomputed on localization CT scans. Additionally, for selected cases, the effects of range uncertainties were investigated. ResultsMedian GTV V98% was 98.7% in the original 2-field plans and 93.7% in their recomputation (p=0.039). The respective values were 99.0% and 98.0% (p=0.039) for the 3–4-field plans and 100.0% and 99.6% (p=0.125) for the 5–7-field plans. CT calibration uncertainties of ±3.5% led to a GTV V98% reduction below 1.5 percentual points in most cases and reaching 3 percentual points for 2-field plans with beam undershoot. ConclusionsThrough jet ventilation, reproducible tumor fixation for proton radiotherapy of lung lesions is achievable, ensuring excellent target coverage in most cases. In few cases, non-optimal patient setup reproducibility induced density changes across beam entrance channels, leading to dosimetric deterioration between planning and delivery.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.