PURPOSE: To evaluate @entity1 specific quality assurance (PSQA) for the delivery of volumetric modulated arc therapy (VMAT) by disease site. To compare @entity262 ( @entity262 ) PSQA pass rates in a dual vendor institution. METHODS: PSQA is performed for VMAT plans using a ScandiDos @entity21316 phantom. Verification plans are calculated using Varian Eclipse and Elekta Monaco treatment planning systems (TPS) for @entity1 treated using Varian Truebeam and Elekta linear accelerators respectively. Individual arcs are delivered to the @entity21316 phantoms and assessed using the gamma index pass criterion(3% Dose Deviation(DD%), 3mm Distance to Agreement( @entity11510 ),10% dose threshold and 90% gamma index). RESULTS: A total of 287 VMAT plans and 680 arcs were analyzed. The passing rates for VMAT QA plans were 95% and 98% for head/neck and pelvis/prostate plans respectively, and 100% for chest/abdomen, spine, lung Stereotactic Body Radiotherapy (SBRT) and Stereotactic Radiosurgery(SRS) plans. Average gamma indices were: (99    2) % for pelvis/prostate, chest/abdomen and lung SBRT plans, (97    4) % for head and neck plans and (98    3) % for spine plans. The average DD% and @entity11510 pass rates ranged from 82% to 90% and 98% to 99% respectively for plans in different disease sites. Paired t-test analysis (two tails) indicated no significant differences in the gamma indices between plans delivered using different @entity262 ; the P values were: 0.08, 0.45, and 0.94 for lung SBRT, head/neck and pelvis/prostate plans respectively. The statistical power for comparing @entity262 in different disease sites with an alpha of 0.05 is 1. CONCLUSION: The Gamma indices based on 3% DD%, 3 mm @entity11510 and 10% dose threshold for the VMAT QA plans in all disease sites were well above 90%, suggesting the possibility of using a more stringent PSQA criterion. No significant differences were observed in the QA of VMAT plans delivered using different @entity262 .

SU-E-T-115: Analysis of XXXX Specific QA for VMAT by Disease Site and Planning-Delivery System Using the ScandiDos Delta4 Phantom.

@entity1 :: ('9606', 'Species') :: ['patients', 'patient'] @entity11510 :: ('MESH:C042899', 'Chemical') :: ['DTA'] @entity262 :: ('MESH:D034721', 'Disease') :: ['planning-delivery system', 'PDS'] @entity21316 :: ('|DEL||4', 'DNAMutation') :: ['Delta4']
@entity1 :: (9606,Species) :: ['Patient']
