title: Computerized estimation of patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy.
abstract: We have developed a computerized method for estimating patient setup errors in portal images based on localized pelvic templates for prostate cancer radiotherapy. The patient setup errors were estimated based on a template-matching technique that compared the portal image and a localized pelvic template image with a clinical target volume produced from a digitally reconstructed radiography (DRR) image of each patient. We evaluated the proposed method by calculating the residual error between the patient setup error obtained by the proposed method and the gold standard setup error determined by consensus between two radiation oncologists. Eleven training cases with prostate cancer were used for development of the proposed method, and then we applied the method to 10 test cases as a validation test. As a result, the residual errors in the anterior-posterior, superior-inferior and left-right directions were smaller than 2 mm for the validation test. The mean residual error was 2.65 ± 1.21 mm in the Euclidean distance for training cases, and 3.10 ± 1.49 mm for the validation test. There was no statistically significant difference in the residual error between the test for training cases and the validation test (P = 0.438). The proposed method appears to be robust for detecting patient setup error in the treatment of prostate cancer radiotherapy.
authors: Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, Japan. arimurah@med.kyushu-u.ac.jp
authors: Hidetaka
authors: H
authors: Arimura
authors: Wataru
authors: W
authors: Itano
authors: Yoshiyuki
authors: Y
authors: Shioyama
authors: Norimasa
authors: N
authors: Matsushita
authors: Taiki
authors: T
authors: Magome
authors: Tadamasa
authors: T
authors: Yoshitake
authors: Shigeo
authors: S
authors: Anai
authors: Katsumasa
authors: K
authors: Nakamura
authors: Satoshi
authors: S
authors: Yoshidome
authors: Akihiko
authors: A
authors: Yamagami
authors: Hiroshi
authors: H
authors: Honda
authors: Masafumi
authors: M
authors: Ohki
authors: Fukai
authors: F
authors: Toyofuku
authors: Hideki
authors: H
authors: Hirata
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging*; D016477:Artifacts; D006801:Humans; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000000981:diagnostic imaging*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D061089:Radiotherapy, Image-Guided / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D014963:X-Ray Intensifying Screens