title: A clinical evaluation of visual feedback-guided breath-hold reproducibility of tumor location.
abstract: The purpose of this study was to evaluate the reproducibility of visual feedback-guided breath-hold using a machine vision system with a charge-coupled device camera and a monocular head-mounted display. Sixteen patients with lung tumors who were treated with stereotactic radiotherapy were enrolled. A machine vision system with a charge-coupled device camera was used for monitoring respiration. A monocular head-mounted display was used to provide the patient with visual feedback about the breathing trace. The patients could control their breathing so that the breathing waveform would fall between the upper and lower threshold lines. Planning and treatment were performed under visual feedback-guided expiratory breath-hold. Electronic portal images were obtained during treatment. The range of cranial-caudal motion of the tumor location during each single breath-hold was calculated as the intra-breath-hold (intra-BH) variability. The maximum displacement between the two to five averaged tumor locations of each single breath-hold was calculated as the inter-breath-hold (inter-BH) variability. All 16 patients tolerated the visual feedback-guided breath-hold maneuvers well. The intra- and inter-BH variability of all patients was 1.5 +/- 0.6 mm and 1.2 +/- 0.5 mm, respectively. A visual feedback-guided breath-hold technique using the machine vision system is feasible with good breath-hold reproducibility.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. yoshitake@radiol.med.kyushu-u.ac.jp
authors.forename: Tadamasa
authors.initials: T
authors.lastname: Yoshitake
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shioyama
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Nakamura
authors.forename: Saiji
authors.initials: S
authors.lastname: Ohga
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nonoshita
authors.forename: Kayoko
authors.initials: K
authors.lastname: Ohnishi
authors.forename: Kotaro
authors.initials: K
authors.lastname: Terashima
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Arimura
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirata
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D056228:Feedback, Sensory; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D011880:Radiotherapy Planning, Computer-Assisted; D015203:Reproducibility of Results; D012119:Respiration; D013238:Stereotaxic Techniques; D014057:Tomography, X-Ray Computed