title: Improved Follow-Up and Response Monitoring of Thoracic Cage Involvement in Multiple Myeloma Using a Novel CT Postprocessing Software: The Lessons We Learned.
abstract: OBJECTIVE
  The purpose of this study is to evaluate the benefit of using novel CT postprocessing software that generates unfolded rib images for more-accurate evaluation of multiple myeloma (MM) at follow-up, response monitoring, and visualization of treatment-related bone changes.
  
  
  METHODS
  Between January 2012 and February 2015, 40 consecutive patients with MM underwent repeated whole-body reduced-dose CT at our institution. The results were retrospectively evaluated and compared with established hematologic markers. Unfolded rib reformatted images were compared with 5- and 1-mm-thick slices with regard to bone changes, bone marrow attenuation, and bone sclerosis.
  
  
  RESULTS
  Hematologic response categories at follow-up were complete response (CR; n = 2), very good partial response (VGPR; n = 1), partial response (PR; n = 9), stable disease (n = 9), and progressive disease (PD; n = 19). The number of lesions increased in 11 patients (all with PD), decreased in two patients (both with CR), and stayed unchanged in 27 patients. The size of the lesions increased in 14 patients (all with PD), decreased in five patients (two with CR, two with PR, and one with stable disease), and remained unchanged in 21 patients. There was a mean (± SD) difference of 27.99 ± 19.71 HU in bone marrow attenuation for patients with PD (p < 0.0001) and -31.24 ± 13.57 HU in the responders group (p = 0.002), whereas patients with stable disease showed stable bone marrow attenuation at follow-up (mean, -3.37 ± 10.55 HU). Increased bone sclerosis was detected in 12 patients (all of whom were receiving therapy). The sensitivity and specificity of unfolded rib images, 5-mm slices, and 1-mm slices were, respectively, 78.9% and 100%, 52.6% and 100%, and 63.2% and 100% for accurate bone response assessment; 100% and 95.2%, 94.74% and 42.9%, and 89.47% and 47.62% for bone marrow attenuation; and 100% and 100%, 58.3% and 100%, and 91.67% and 100% for sclerosis.
  
  
  CONCLUSIONS
  For therapy response assessment, unfolded rib reading is more accurate than transverse CT slices.
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Strasse 3, Tübingen D-72076, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Bier
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Strasse 3, Tübingen D-72076, Germany.
authors.forename: Deedar Farhad
authors.initials: DF
authors.lastname: Mustafa
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Strasse 3, Tübingen D-72076, Germany.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kloth
authors.affiliation: 2 Department of Internal Medicine II, Eberhard-Kals-University Tübingen, Tübingen, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Weisel
authors.affiliation: 3 Sector Imaging and Interventional Radiology, Siemens AG Healthcare, Forchheim, Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Ditt
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Strasse 3, Tübingen D-72076, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Nikolaou
authors.affiliation: 1 Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University Tübingen, Hoppe-Seyler-Strasse 3, Tübingen D-72076, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Horger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000000981:diagnostic imaging* / Q000473:pathology; D009367:Neoplasm Staging; D058996:Quality Improvement; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012272:Ribs / Q000000981:diagnostic imaging* / Q000473:pathology; D012680:Sensitivity and Specificity; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging
keywords: MDCT; follow-up; multiple myeloma; osteolyses; ribs