Encrypted login | home

Program Information

A Lean Truebeam Commissioning Beam Dataset for Multi-Linac Facilities-The University of Maryland Experience

C Kalavagunta

C Kalavagunta*, S Becker , A Gopal , K Prado , Univ. of Maryland School Of Medicine, Baltimore, MD


SU-I-GPD-T-486 (Sunday, July 30, 2017) 3:00 PM - 6:00 PM Room: Exhibit Hall

Purpose: Linac commissioning beam scanning measurements are one of the most time-consuming and crucial activities in therapy physics. Our institution is a multi-linac facility with beam-matched accelerators and a single beam-modeled Raystation (RS) treatment planning system (TPS) which enabled use of a lean beam scanning dataset in commissioning a Truebeam (TB) 2.0 in July 2015. This abstract describes the unique aspects of this process and dataset.

Methods: The TB 2.0 was purchased with the Varian defined “enhanced beam conformance” (EBC) option (Tolerance of ± 0.5-0.7% for depth dose at 10 cm and ±1.5mm for dmax specification). A lean TB 2.0 beam scan dataset was obtained as shown in Table 1. The TB 2.0 scan data were compared with 1) Varian Standard (TB representative data or if absent, Clinac gold data), 2) RS 4.5 TPS computed model, 3) Trilogy (C3 linac with 6X & 18X only) and 4) (TB 1.6 linac with all energies except 18X). The goal was to verify good agreement between the TB 2.0 data, the Varian standard and the RS model data.

Results: Beam scan data was acquired over 2 days. The variation in relative output factors, depth doses, off axis ratios, between the four datasets for >99.5% of the datasets were found to be less than 1%. Data that did not match the model was found to be consistent with corresponding TB 1.6 and Trilogy data.

Conclusion: The lean TB 2.0 beam scan dataset is an effective and efficient alternative that can be used by multi-linac facilities for Truebeam commissioning.References:1. Das, I et. al. Med. Phys. 39 (2012).2. Sjostrom, D et. al. Acta Oncologica, 48 (2009).3. Watts, R. Med. Phys. 26 (1999).4. Das, I et al., Med. Phys. (35) (2008).5. Grzetic, S et. al. Med. Phys. 42 (2015).

Contact Email: