J Lung Cancer.  2006 Dec;5(2):89-91. 10.6058/jlc.2006.5.2.89.

On-line Setup for Lung Cancer Patient in Stereotactic Radiation Surgery using CBCT

• Park SH
• Choi EK
• Ahn SD
• Lee SW
• Shin SS
• Kim JH

• KMID: 2200167
• DOI: http://doi.org/10.6058/jlc.2006.5.2.89

Abstract

PURPOSE: On-line setup procedure was performed before treatment for lung cancer patient for stereotactic radiation surgery (SRS) using recently introduced Cone Beam CT.
MATERIALS AND METHODS
Cone Beam CT was performed for 10 patients who did SRS during 18 July and 1 September, 2006 using On Board Imager (OPB) system made by Varian, USA. The treatment position of patient was corrected comparing Images obtaining from CBCT and used in treatment planning.
RESULTS
Comparing the CBCT images and CT images used in treatment planning, the movement of the couch is 2.3+/-2.3 mm, 1.8+/-2.8 mm, 0.3+/-3.5 mm for vertical, lateral, and longitudinal direction. It took about 1 hr for conventional treatment procedure in image acquisition of CT before treatment and image registration. But it took about 4~7 minute in on-line setup using CBCT (1~2 min for image acquisition using CBCT, 2~3 min for CT reconstruction of 2.5 mm slice thickness, 1~2 min for on-line setup using image registration). CONCLUTION: The accurate treatment could be performed after tumor localization for SRS using CBCT images. And the consumed time for tumor localization was reduced significantly.

Keyword

Cone beam CT; Stereotactic radiation surgery; Lung cancer; Image guided radiation therapy

MeSH Terms

Cone-Beam Computed Tomography
Humans
Lung Neoplasms*
Lung*
Radiotherapy, Image-Guided

Figure

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  Fig. 1. On Board Imager (OBI) system installed on the conventional Unac. A X-ray generator is shown in the left side, and the detector is shown in the right side.

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  Fig. 2. Cone Beam CT (CBCT) images obtained using On Board Imager (OBI) system. The original planned CT images are shown in the right upper, and the other images are CBCT images with gross tumor volume (GTV), planning target volume (PTV) contoured in the planned CT images. The correction shift value of the couch are shown in the lower part.

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  Fig. 3. Treatment procedure of lung SRS patient for conventional treatment using exactrac system and new procedure using CBCT, EPID: electronic portal imaging devices.

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  Fig. 4. Couch shift value, resulting from on-line setup using CBCT, for 10 SRS lung patients.

Reference

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