Robustness of single-isocenter multiple-metastasis stereotactic radiosurgery end-to-end testing across institutions
Daniel Saenz, Niko Papanikolaou, Emmanouil Zoros, Evangelos Pappas, Michael Reiner, Lip Teck Chew, Hooi Yin Lim, Sam Hancock, Alex Nebelsky, Christopher Njeh and Georgios Anagnostopoulos
The accuracy of stereotactic radiosurgery (SRS) to multiple metastases with a single-isocenter using high definition dynamic radiosurgery (HDRS) was evaluated across institutions. An SRS plan was delivered at six HDRS-capable institutions to an anthropomorphic phantom consisting of point, film, and 3D-gel dosimeters. Direct dose comparison and gamma analysis were used to evaluate the accuracy. Point measurements averaged across institutions were within 1.2±0.5%. The average gamma passing rate in the film was 96.6±2.2% (3%/2 mm). For targets within 4 cm of the isocenter, the 3D dosimetric gel gamma passing rate averaged across institutions was >90% (3%/2 mm). The targeting accuracy of high definition dynamic radiosurgery assessed by geometrical offset of the center of dose distributions across multiple institutions in this study was within 1 mm for targets within 4 cm of isocenter. Across variations in clinical practice, comparable dosimetry and localization is possible with this treatment planning and delivery technique.
Keywords: Gel, dosimetry, quality, assurance, stereotactic, radiosurgery