Dosimetric verification of complex radiotherapy with a 3D optically based dosimetry system: Dose painting and target tracking

TY - JOUR

T1 - Dosimetric verification of complex radiotherapy with a 3D optically based dosimetry system: Dose painting and target tracking

AU - Skyt, Peter S

AU - Petersen, Jørgen B B

AU - Yates, Esben S

AU - Poulsen, Per Rugaard

AU - Ravkilde, Thomas L

AU - Balling, Peter

AU - Muren, Ludvig P

PY - 2013/10

Y1 - 2013/10

N2 - Background. The increasing complexity of radiotherapy (RT) has motivated research into three-dimensional (3D) dosimetry. In this study we investigate the use of 3D dosimetry with polymerizing gels and optical computed tomography (optical CT) as a verification tool for complex RT: dose painting and target tracking. Materials and Methods. For the dose painting studies, two dosimeters were irradiated with a seven-field intensity modulated radiotherapy (IMRT) plan with and without dose prescription based on a hypoxia image dataset of a head and neck patient. In the tracking experiments, two dosimeters were irradiated with a volumetric modulated arc therapy (VMAT) plan with and without clinically measured prostate motion and a third with both motion and target tracking. To assess the performance, 3D gamma analyses were performed between measured and calculated stationary dose distributions. Results. Gamma pass-rates of 95.3% and 97.3% were achieved for the standard and dose-painted IMRT plans. Gamma pass-rates of 91.4% and 54.4% were obtained for the stationary and moving dosimeter, respectively, while tracking increased the pass-rate for the moving dosimeter to 90.4%. Conclusions. This study has shown that the 3D dosimetry system can reproduce and thus verify complex dose distributions, also when influenced by motion.

AB - Background. The increasing complexity of radiotherapy (RT) has motivated research into three-dimensional (3D) dosimetry. In this study we investigate the use of 3D dosimetry with polymerizing gels and optical computed tomography (optical CT) as a verification tool for complex RT: dose painting and target tracking. Materials and Methods. For the dose painting studies, two dosimeters were irradiated with a seven-field intensity modulated radiotherapy (IMRT) plan with and without dose prescription based on a hypoxia image dataset of a head and neck patient. In the tracking experiments, two dosimeters were irradiated with a volumetric modulated arc therapy (VMAT) plan with and without clinically measured prostate motion and a third with both motion and target tracking. To assess the performance, 3D gamma analyses were performed between measured and calculated stationary dose distributions. Results. Gamma pass-rates of 95.3% and 97.3% were achieved for the standard and dose-painted IMRT plans. Gamma pass-rates of 91.4% and 54.4% were obtained for the stationary and moving dosimeter, respectively, while tracking increased the pass-rate for the moving dosimeter to 90.4%. Conclusions. This study has shown that the 3D dosimetry system can reproduce and thus verify complex dose distributions, also when influenced by motion.

U2 - 10.3109/0284186X.2013.813965

DO - 10.3109/0284186X.2013.813965

M3 - Journal article

C2 - 23957684

SN - 0284-186X

VL - 52

SP - 1445

EP - 1450

JO - Acta Oncologica

JF - Acta Oncologica

IS - 7

ER -