Effect of VERO pan‐tilt motion on the dose distribution

نویسندگان

  • Heru Prasetio
  • Indra Yohannes
  • Christoph Bert
چکیده

Tumor tracking is an option for intra-fractional motion management in radiotherapy. The VERO gimbal tracking system creates a unique beam geometry and understanding the effect of the gimbal motion in terms of dose distribution is important to assess the dose deviation from the reference conditions. Beam profiles, output factors (OF) and percentage depth doses (PDD) were measured and evaluated to investigate this effect. In order to find regions affected by the pan-tilt motion, synthesized 2D dose distributions were generated. An evaluation of the 2D dose distribution with the reference position was done using dose difference criteria 1%-4%. The OF and point dose at central axis were measured and compared with the reference position. Furthermore, the PDDs were measured using a special monitoring approach to filtering inaccurate points during the acquisition. Beam profiles evaluation showed that the effect of pan-tilt at inline direction was stronger than at the crossline direction. The maximum average deviation of the full width half maximum (FWHM), flatness, symmetry, penumbra left and right were 0.39 ± 0.25 mm, 0.62 ± 0.50%, 0.76 ± 0.59%, 0.22 ± 0.16 mm, and 0.19 ± 0.15 mm respectively. The ÔF and the measured dose average deviation were <0.5%. The mechanical accuracies during the PDD measurements were 0.28 ± 0.09 mm and 0.21 ± 0.09 mm for pan and tilt and pan or tilt position. The PDD average deviations were 0.58 ± 0.26 % and 0.54 ± 0.25 % for pan-or-tilt and pan-and-tilt position respectively. All the results showed that the deviation at pan and tilt position are higher than pan or tilt. The most influences were observed for the penumbra region and the shift of radiation beam path.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The influence of respiratory motion on dose distribution of 3D-CRT and IMRT- A simulation study

Background: 3DCRT (three-dimensional conformal radiotherapy) and IMRT (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. However, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. The purpose of this study is to evaluate the imp...

متن کامل

Investigation of tumor motion influence on applied dose distribution in conventional proton therapy vs. IMPT a 4D Monte Carlo simulation study

Background: in radiation treatment of moving targets located in thorax region of patient body, the delivered dose does not match with the planned treatment, resulting in some over and under dosage in the tumor volume, as a function of motion magnitude and frequency. Several efforts have been done to investigate the target motion effects on dose distribution in the target and surrounding normal ...

متن کامل

Optical Motion Capture System with Pan-Tilt Camera Tracking and Realtime Data Processing

This paper presents the realtime processing of optical motion capture with pan-tilt camera tracking. Pantilt camera tracking expands the range of capturing eld dynamically. Asymmetrical marker distribution and polyhedra search algorithm realize robust labeling against marker missing. The algorithm is developed for parallel cluster computation and enables realtime data processing. Experimental r...

متن کامل

Respiratory motion effect on tumor and normal tissue doses in patients with lung cancer, treated with Intensity Modulation Radiation Therapy and Three Dimensional Conformal Radiation Therapy.

Introduction:   The aim of this study is to investigate the effect of respiratory motion during radiation therapy in patient with lung cancer and comparison of dosimetric parameters between Intensity modulation radiation therapy and three-dimensional conformal radiotherapy in lung cancer.   Materials and Methods:   Two CT scan was performred for each pati...

متن کامل

Joanneum Research at TRECVID 2005 – Camera Motion Detection

Low-level feature extraction (camera motion) Ground truth annotation Manual camera motion annotation has been performed by three groups using a tool provided by Joanneum Research. Some types of content made it difficult or impossible for human annotators to describe the camera motion. The comparison of annotations of the same content done by two groups shows significant differences for some fea...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 18  شماره 

صفحات  -

تاریخ انتشار 2017