2Department of Radiation Oncology, Memorial Şişli Hospital, İstanbul-Turkey DOI : 10.5505/tjo.2019.2075 OBJECTIVE
This study aims to investigate the dosimetric effects of Acuros XB (AXB) and Anisotropic Analytical algorithms (AAA) on intensity-modulated radiotherapy (IMRT) and volumetric modulated arc therapy (VMAT) techniques for nasal cavity and paranasal sinus tumors.
METHODS
This study included 10 patients with the nasal cavity and paranasal sinus tumors, and 7-field non-coplanar
IMRT plan and VMAT plans were generated with 6-MV photon beams specially selected for each
patient anatomy. The effects on planning target volume (PTV) and organ-at-risk (OAR) were evaluated
using AXB and AAA in each treatment technique to compare the accuracy of the calculation.
RESULTS
Conformity Index (CI) values for PTV were found to be 1.02±0.02 and 1.03±0.03 for VMATAAA and
VMATAXB plans, respectively and 1.18±0.03 and 1.20±0.02 for IMRTAAA and IMRTAXB plans, respectively.
Regarding heterogeneity index (HI) values, VMATAAA and VMATAXB plans (0.025±0.02; 0.029±0.02)
were found to have better HI values than IMRTAAA and IMRTAXB plans (0.246±0.02; 0.335±0.03). Depending
on the technique and algorithm used, a dose difference of 4%-14% was detected between PTV
Dmin values.
CONCLUSION
The selection of AXB algorithm in treatment regions with high tissue heterogeneity will give more accurate
dose calculation results for PTV and healthy tissues.