Feasibility of EPID Based In-Vivo Dosimetry for On-Couch Adaptive Radiotherapy

ASTRO Poster by
G. Razinskas¹, R. Schindhelm¹, J. Tamihardja¹, L. Bohorquez² and S. Wegener¹
1 University Hospital Wurzburg, Department of Radiation Oncology, Wurzburg, Germany
2 LAP, Boynton Beach, FL

Aim
The use of EPID recordings promises to detect deviations in beam delivery or patient position, incorrect sCT data, and anatomical changes. The purpose of this research was to evaluate the feasibility of using a new commercial technology available for in-vivo dose reconstruction based on EPID exit beam measurements.

Conclusion
In-vivo EPID dosimetry of adaptive clinical plans is feasible. It was exemplary demonstrated that it reveals fractions with noticeable anatomical changes between the sCT and the patient anatomy during treatment. As new recommendations were published on in-vivo dosimetry through TG 307 [3], the development of new clinical tools and evaluation of existing commercial solutions is essential, also in the context of the growing use of on-couch adaptive technology.