title: Osteolytica: An automated image analysis software package that rapidly measures cancer-induced osteolytic lesions in in vivo models with greater reproducibility compared to other commonly used methods.
abstract: Methods currently used to analyse osteolytic lesions caused by malignancies such as multiple myeloma and metastatic breast cancer vary from basic 2-D X-ray analysis to 2-D images of micro-CT datasets analysed with non-specialised image software such as ImageJ. However, these methods have significant limitations. They do not capture 3-D data, they are time-consuming and they often suffer from inter-user variability. We therefore sought to develop a rapid and reproducible method to analyse 3-D osteolytic lesions in mice with cancer-induced bone disease. To this end, we have developed Osteolytica, an image analysis software method featuring an easy to use, step-by-step interface to measure lytic bone lesions. Osteolytica utilises novel graphics card acceleration (parallel computing) and 3-D rendering to provide rapid reconstruction and analysis of osteolytic lesions. To evaluate the use of Osteolytica we analysed tibial micro-CT datasets from murine models of cancer-induced bone disease and compared the results to those obtained using a standard ImageJ analysis method. Firstly, to assess inter-user variability we deployed four independent researchers to analyse tibial datasets from the U266-NSG murine model of myeloma. Using ImageJ, inter-user variability between the bones was substantial (±19.6%), in contrast to using Osteolytica, which demonstrated minimal variability (±0.5%). Secondly, tibial datasets from U266-bearing NSG mice or BALB/c mice injected with the metastatic breast cancer cell line 4T1 were compared to tibial datasets from aged and sex-matched non-tumour control mice. Analyses by both Osteolytica and ImageJ showed significant increases in bone lesion area in tumour-bearing mice compared to control mice. These results confirm that Osteolytica performs as well as the current 2-D ImageJ osteolytic lesion analysis method. However, Osteolytica is advantageous in that it analyses over the entirety of the bone volume (as opposed to selected 2-D images), it is a more rapid method and it has less user variability.
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: h.r.evans@sheffield.ac.uk.
authors.forename: H R
authors.initials: HR
authors.lastname: Evans
authors.affiliation: Department of Computer Science, University of Sheffield, Mappin Street, Sheffield S1 4DP, UK. Electronic address: t.karmakharm@sheffield.ac.uk.
authors.forename: T
authors.initials: T
authors.lastname: Karmakharm
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: m.a.lawson@sheffield.ac.uk.
authors.forename: M A
authors.initials: MA
authors.lastname: Lawson
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: beccywalker@googlemail.com.
authors.forename: R E
authors.initials: RE
authors.lastname: Walker
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: Wilson_26_@hotmail.com.
authors.forename: W
authors.initials: W
authors.lastname: Harris
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: clairfellows@live.co.uk.
authors.forename: C
authors.initials: C
authors.lastname: Fellows
authors.affiliation: Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK. Electronic address: mdp11idh@sheffield.ac.uk.
authors.forename: I D
authors.initials: ID
authors.lastname: Huggins
authors.affiliation: Department of Computer Science, University of Sheffield, Mappin Street, Sheffield S1 4DP, UK; Insigneo Institute for In silico Medicine, The Pam Liversige Building, Sir Frederick Mappin Building, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK. Electronic address: p.richmond@sheffield.ac.uk.
authors.forename: P
authors.initials: P
authors.lastname: Richmond
authors.affiliation: Sheffield Myeloma Research Team, Department of Oncology, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Mellanby Centre for Bone Research, Medical School, University of Sheffield, Beech Hill Road, Sheffield S10 2RX, UK; Department of Haematology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK; Insigneo Institute for In silico Medicine, The Pam Liversige Building, Sir Frederick Mappin Building, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK. Electronic address: a.d.chantry@sheffield.ac.uk.
authors.forename: A D
authors.initials: AD
authors.lastname: Chantry
mesh_terms: D000818:Animals; D001331:Automation; D001943:Breast Neoplasms / Q000150:complications; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008807:Mice, Inbred BALB C; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications* / Q000473:pathology; D010014:Osteolysis / Q000000981:diagnostic imaging* / Q000209:etiology*; D015203:Reproducibility of Results; D012984:Software; D014584:User-Computer Interface; D055114:X-Ray Microtomography
keywords: Bone; Breast cancer; Lesion; MicroCT; Multiple myeloma