title: Method for data analysis in different institutions: example of image guidance of prostate cancer patients.
abstract: Multi-institutional collaborations allow for more information to be analyzed but the data from different sources may vary in the subgroup sizes and/or conditions of measuring. Rigorous statistical analysis is required for pooling the data in a larger set. Careful comparison of all the components of the data acquisition is indispensable: identical conditions allow for enlargement of the database with improved statistical analysis, clearly defined differences provide opportunity for establishing a better practice. The optimal sequence of required normality, asymptotic normality, and independence tests is proposed. An example of analysis of six subgroups of position corrections in three directions obtained during image guidance procedures for 216 prostate cancer patients from two institutions is presented.
authors.affiliation: Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland; Department of Electroradiology, University of Medical Sciences, Poznan, Poland. Electronic address: tomasz.piotrowski@me.com.
authors.forename: T
authors.initials: T
authors.lastname: Piotrowski
authors.affiliation: Department of Radiation Oncology, London Regional Cancer Program, London Health Sciences Centre, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada; Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada. Electronic address: George.Rodrigues@lhsc.on.ca.
authors.forename: G
authors.initials: G
authors.lastname: Rodrigues
authors.affiliation: 2nd Radiotherapy Department, Greater Poland Cancer Centre, Poznan, Poland. Electronic address: bajonski@wp.pl.
authors.forename: T
authors.initials: T
authors.lastname: Bajon
authors.affiliation: Department of Physics, London Regional Cancer Program, London Health Sciences Centre, Canada; Department of Biophysics, University of Western Ontario, London, Ontario, Canada; Department of Oncology, University of Western Ontario, London, Ontario, Canada. Electronic address: Slav.Yartsev@lhsc.on.ca.
authors.forename: S
authors.initials: S
authors.lastname: Yartsev
mesh_terms: D003299:Cooperative Behavior; D016208:Databases, Factual; D006801:Humans; D008297:Male; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D061089:Radiotherapy, Image-Guided; D013223:Statistics as Topic / Q000379:methods*; D014057:Tomography, X-Ray Computed
keywords: Image co-registration; Image guidance; Pooled database; Radiation therapy; Statistical tests