Reproducibility of the abdominal and chest wall position by voluntary breath-hold technique using a laser-based monitoring and visual feedback system.
OBJECTIVE
The voluntary breath-hold (BH) technique is a simple method to control the respiration-related motion of a tumor during irradiation. However, the abdominal and chest wall position may not be accurately reproduced using the BH technique. The purpose of this study was to examine whether visual feedback can reduce the fluctuation in wall motion during BH using a new respiratory monitoring device.


METHODS
We developed a laser-based BH monitoring and visual feedback system. For this study, five healthy volunteers were enrolled. The volunteers, practicing abdominal breathing, performed shallow end-expiration BH (SEBH), shallow end-inspiration BH (SIBH), and deep end-inspiration BH (DIBH) with or without visual feedback. The abdominal and chest wall positions were measured at 80-ms intervals during BHs.


RESULTS
The fluctuation in the chest wall position was smaller than that of the abdominal wall position. The reproducibility of the wall position was improved by visual feedback. With a monitoring device, visual feedback reduced the mean deviation of the abdominal wall from 2.1 +/- 1.3 mm to 1.5 +/- 0.5 mm, 2.5 +/- 1.9 mm to 1.1 +/- 0.4 mm, and 6.6 +/- 2.4 mm to 2.6 +/- 1.4 mm in SEBH, SIBH, and DIBH, respectively.


CONCLUSIONS
Volunteers can perform the BH maneuver in a highly reproducible fashion when informed about the position of the wall, although in the case of DIBH, the deviation in the wall position remained substantial.
Nakamura
Katsumasa
K
Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. nakam@radiol.med.kyushu-u.ac.jp
Shioyama
Yoshiyuki
Y
Nomoto
Satoru
S
Ohga
Saiji
S
Toba
Takashi
T
Yoshitake
Tadamasa
T
Anai
Shigeo
S
Terashima
Hiromi
H
Honda
Hiroshi
H
D034861:Abdominal Wall; D000328:Adult; D005240:Feasibility Studies; D005246:Feedback; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009068:Movement; D015203:Reproducibility of Results; D012119:Respiration; D035441:Thoracic Wall