Impact of patient rotational errors on target and critical structure dose in IMRT: A 3D simulation study

7th International Conference on 3D Radiation Dosimetry

Arumugam, S.^1 ; Xing, A.^1 ; Vial, P.^1,2 ; Scotti, A.^1 ; Stirton, R.^1 ; Goozee, G.^1,3 ; Holloway, Lois^1,2,4

Liverpool and Macarthur Cancer Therapy Centres, Ingham Institute, Liverpool Hospital, Sydney, NSW, Australia^1

Institute of Medical Physics, School of Physics, University of Sydney, Sydney, NSW, Australia^2

University of New South Wales, Sydney, NSW, Australia^3

Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW, Australia^4

关键词: 3D simulations;    Critical structures;    Head and neck;    Patient positioning;    Rotational errors;    Target volumes;    Treatment plans;    Treatment sites;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/444/1/012045/pdf
DOI  :  10.1088/1742-6596/444/1/012045

来源: IOP

【 摘 要 】

The impact of 3D rotational errors in patient positioning on dose delivered target volumes and critical structures in IMRT was studied. Patient rotational errors ranging from -30to +30was introduced to IMRT treatment plans of pelvis, head and neck and brain treatment sites and the impact of rotational error on DVH metrics was assessed. The magnitude of impact of rotational error on the error in dose delivered to the target volume and critical structures depends on the location of the structures from plan isocentre. In studied plans, a maximum percentage difference of up to -9.8(1s=13.4) % in D95 to PTV was observed for head and neck treatments. Similarly, in Brain treatments a maximum difference of up to 24.0(1s=33.0) % in maximum dose of Optic chiasm was observed. The results suggest that failure to correct patient's rotational error results in under-dosage to target volumes and over-dosage to the critical structures in some specific treatment scenarios.