Development of Respiration Gating RT Technique using Moving Phantom and Ultrasound Sensor: a feasibility study.
- Author:
Suk LEE
1
;
Sang Hoon LEE
;
Dongho SHIN
;
Dae Sik YANG
;
Myung Sun CHOI
;
Chul Yong KIM
Author Information
1. Department of Radiation Oncology, Korea University Medical Center, Seoul, Korea. sukmp@hanmail.net
- Publication Type:Original Article
- Keywords:
Respiration gating radiation therapy technique;
Moving phantom;
Patient' body movement;
Ultra- sonic sensor;
Radiotherapy
- MeSH:
Animals;
Feasibility Studies*;
Guinea Pigs;
Liver;
Microcomputers;
Radiotherapy;
Respiration*;
Ultrasonics;
Ultrasonography*
- From:The Journal of the Korean Society for Therapeutic Radiology and Oncology
2004;22(4):316-324
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
PURPOSE: In radiotherapy of tumors in liver, enough planning target volume (PTV) margins are necessary to compensate breathing-related movement of tumor volumes. To overcome the problems, this study aims to obtain patients' body movements by using a moving phantom and an ultrasonic sensor, and to develop respiration gating techniques that can adjust patients' beds by using reversed values of the data obtained. MATERIALS AND METHODS: The phantom made to measure patients' body movements is composed of a microprocessor (BS II, 20 MHz, 8K Byte), a sensor (Ultra-Sonic, range 3~3 m), host computer (RS232C) and stepping motor (torque 2.3 Kg) etc., and the program to control and operate it was developed. The program allows the phantom to move within the maximum range of 2 cm, its movements and corrections to take place in order, and x, y and z to move successively. After the moving phantom was adjusted by entering random movement data (three dimensional data form with distance of 2 cm), and the phantom movements were acquired using the ultra sonic sensor, the two data were compared and analyzed. And then, after the movements by respiration were acquired by using guinea pigs, the real-time respiration gating techniques were drawn by operating the phantom with the reversed values of the data. RESULTS: The result of analyzing the acquisition-correction delay time for the three types of data values and about each value separately shows that the data values coincided with one another within 1% and that the acquisition-correction delay time was obtained real-time (2.34x10-4 sec). CONCLUSION: This study successfully confirms the clinic application possibility of respiration gating techniques by using a moving phantom and an ultrasonic sensor. With ongoing development of additional analysis system, which can be used in real-time set-up reproducibility analysis, it may be beneficially used in radiotherapy of moving tumors.
