6X acuros algorithm validation in the presence of inhomogeneities for VMAT treatment planning.
Rep Pract Oncol Radiother
; 25(4): 539-547, 2020.
Article
em En
| MEDLINE
| ID: mdl-32494226
ABSTRACT
AIM:
To validate the Acuros®XB (AXB) dose calculation algorithm for a 6â¯MV beam from the Varian TrueBeam treatment units.BACKGROUND:
Currently Anisotropic Analytic Algorithm (AAA) is clinically used on authors' department but AXB could replace it for VMAT treatments in regions where inhomogeneities and free air are present. MATERIALS ANDMETHODS:
Two steps are followed in the validation process of a new dose calculation algorithm. The first is to check the accuracy of algorithm for a homogenous phantom and regular fields. Multiple fields of increasing complexity have been acquired using a Mapcheck diode array. The accuracy of the algorithm was evaluated using the gamma analysis method. The second is to validate the algorithm in the presence of heterogeneous media. Planar absolute dose was measured with GafChromic®EBT2 film and was compared with the dose calculated by AXB. Gamma analysis was performed between Mapcheck measurements and AXB dose calculations, at a range of clinical source-surface distance.RESULTS:
For SSDs ranging from 80 to 100â¯cm, the results show a minimum pass rate of 95% between AXB and Mapcheck acquisition. For open 6â¯MV photon beam interacting with a phantom with an air gap, the agreement after the air gap between AXB and GafChromic®EBT2 is less than 1% in the 3â¯×â¯3cm2 field and less than 2% in the 10â¯×â¯10â¯cm2 field.CONCLUSIONS:
AXB has advanced modelling of lateral electron transport that enables a more accurate dose calculation in heterogeneous regions and, compared with AAA, improves accuracy between different density interfaces. This will be of particular benefit for head/neck treatments.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article