- Title
- Validation of virtual water phantom software for pre-treatment verification of single-isocenter multiple-target stereotactic radiosurgery
- Creator
- Calvo-Ortega, Juan-Francisco; Greer, Peter B.; Hermida-López, Marcelino; Moragues-Femenía, Sandra; Laosa-Bello, Coral; Casals-Farran, Joan
- Relation
- Journal of Applied Clinical Medical Physics Vol. 22, Issue 6, p. 241-252
- Publisher Link
- http://dx.doi.org/10.1002/acm2.13269
- Publisher
- John Wiley & Sons
- Resource Type
- journal article
- Date
- 2021
- Description
- The aim of this study was to benchmark the accuracy of the VIrtual Phantom Epid dose Reconstruction (VIPER) software for pre-treatment dosimetric verification of multiple-target stereotactic radiosurgery (SRS). VIPER is an EPID-based method to reconstruct a 3D dose distribution in a virtual phantom from in-air portal images. Validation of the VIPER dose calculation was assessed using several MLC-defined fields for a 6 MV photon beam. Central axis percent depth doses (PDDs) and output factors were measured with an ionization chamber in a water tank, while dose planes at a depth of 10 cm in a solid flat phantom were acquired with radiochromic films. The accuracy of VIPER for multiple-target SRS plan verification was benchmarked against Monte Carlo simulations. Eighteen multiple-target SRS plans designed with the Eclipse treatment planning system were mapped to a cylindrical water phantom. For each plan, the 3D dose distribution reconstructed by VIPER within the phantom was compared with the Monte Carlo simulation, using a 3D gamma analysis. Dose differences (VIPER vs. measurements) generally within 2% were found for the MLC-defined fields, while film dosimetry revealed gamma passing rates (GPRs) ≥95% for a 3%/1 mm criteria. For the 18 multiple-target SRS plans, average 3D GPRs greater than 93% and 98% for the 3%/2 mm and 5%/2 mm criteria, respectively. Our results validate the use of VIPER as a dosimetric verification tool for pre-treatment QA of single-isocenter multiple-target SRS plans. The method requires no setup time on the linac and results in an accurate 3D characterization of the delivered dose.
- Subject
- multiiple-target; stereotactic radiosurgery (SRS); virtual phantom; water
- Identifier
- http://hdl.handle.net/1959.13/1473373
- Identifier
- uon:49000
- Identifier
- ISSN:1526-9914
- Rights
- x
- Language
- eng
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