Immobilisation precision in VMAT for oral cancer patients

10th International Seminar on Medical Physics; 1st AMDI International Oncology Symposium

物理学;医药卫生

Norfadilah, M.N.^1,2 ; Ahmad, R.^1 ; Heng, S.P.^3 ; Lam, K.S.^2 ; Radzi, A. B. Ahmad^2 ; John, L.S.H.^2

Diagnostic and Radiotherapy Programme, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur

50300, Malaysia^1

Radiotherapy Unit, Cancer Centre, Pantai Hospital Kuala Lumpur, Kuala Lumpur

59100, Malaysia^2

Cancer, Radiosurgery and Nuclear Medicine Centre, Sunway Medical Centre, Selangor, Petaling Jaya

46150, Malaysia^3

关键词: Anterior posteriors;    Clinical target volumes;    Cone-beam computed tomography;    Image guided radiotherapy;    Mean displacement;    Oral cancer patients;    Planning target volumes;    Rotational directions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/851/1/012025/pdf
DOI  :  10.1088/1742-6596/851/1/012025

学科分类：卫生学

来源: IOP

【 摘 要 】

A study was conducted to evaluate and quantify a precision of the interfraction setup with different immobilisation devices throughout the treatment time. Local setup accuracy was analysed for 8 oral cancer patients receiving radiotherapy; 4 with HeadFIX®mouthpiece moulded with wax (HFW) and 4 with 10 ml/cc syringe barrel (SYR). Each patients underwent Image Guided Radiotherapy (IGRT) with total of 209 cone-beam computed tomography (CBCT) data sets for position set up errors measurement. The setup variations in the mediolateral (ML), craniocaudal (CC), and anteroposterior (AP) dimensions were measured. Overall mean displacement (M), the population systematic (Σ) and random (σ) errors and the 3D vector length were calculated. Clinical target volume to planning target volume (CTV-PTV) margins were calculated according to the van Herk formula (2.5Σ+0.7σ). The M values for both group were