title: Adult advanced chronic lymphocytic leukemia: computational analysis of whole-body CT documents a bone structure alteration.
abstract: OBJECTIVE
  To assess the presence of alteration of bone structure and bone marrow metabolism in adult patients who were suspected of having advanced chronic lymphocytic leukemia (ACLL) by using a computational prognostic model that was based on computational analysis of positron emission tomography (PET)/computed tomography (CT) images.
  
  
  METHODS
  In this retrospective study, all patients signed written informed consent as a requisite to undergo PET/CT examination. However, due to its observational nature, approval from the ethical committee was not deemed necessary. Twenty-two previously untreated chronic lymphocytic leukemia patients underwent PET/CT for disease progression. PET/CT images were analyzed by using dedicated software, capable of recognizing an external 2-pixel bone ring whose Hounsfield coefficient served as cutoff to recognize trabecular and compact bone. PET/CT data from 22 age- and sex-matched control subjects were used as comparison. All data are reported as means ± standard deviations. The Student t test, log-rank, or Cox proportional hazards model were used as appropriate, considering a difference with a P value of less than .05 as significant.
  
  
  RESULTS
  Trabecular bone was expanded in ACLL patients and occupied a larger fraction of the skeleton with respect to control subjects (mean, 39% ± 5 [standard deviation] vs 31% ± 7; ie, 32 of 81 mL/kg of ideal body weight vs 27 of 86 mL/kg of ideal body weight, respectively; P < .001). After stratification according to median value, patients with a ratio of trabecular to skeletal bone volume of more than 37.3% showed an actuarial 2-year survival of 18%, compared with 82% for those with a ratio of less than 37.3% (P < .001), independent from age, sex, biological markers, and disease duration.
  
  
  CONCLUSIONS
  These data suggest that computational assessment of skeletal alterations might represent a new window for prediction of the clinical course of the disease.
authors.affiliation: From the Departments of Nuclear Medicine Unit (F. Fiz, R.P., F.B., S.M., G.B., G.S.), Hematology (M. Miglino), Hematology and Bone Marrow Transplantation (A.B.), and Epidemiology (P.B.), IRCCS San Martino-IST, University of Genoa, L.go R. Benzi 10, 16132 Genoa, Italy; CNR Institute of Molecular Bioimaging and Physiology, Milan, Section of Genoa, Genoa, Italy (C.M.); Nuclear Medicine Unit, U. Parini Hospital, Aosta, Italy (M. Massollo); Department of Mathematics, University of Genoa, Genoa, Italy (C.C., M.P.); and Stem Cell Laboratory, IRCCS Pediatric Institute G. Gaslini, Genoa, Italy (F. Frassoni).
authors.forename: Francesco
authors.initials: F
authors.lastname: Fiz
authors.forename: Cecilia
authors.initials: C
authors.lastname: Marini
authors.forename: Roberta
authors.initials: R
authors.lastname: Piva
authors.forename: Maurizio
authors.initials: M
authors.lastname: Miglino
authors.forename: Michela
authors.initials: M
authors.lastname: Massollo
authors.forename: Francesca
authors.initials: F
authors.lastname: Bongioanni
authors.forename: Silvia
authors.initials: S
authors.lastname: Morbelli
authors.forename: Gianluca
authors.initials: G
authors.lastname: Bottoni
authors.forename: Cristina
authors.initials: C
authors.lastname: Campi
authors.forename: Andrea
authors.initials: A
authors.lastname: Bacigalupo
authors.forename: Paolo
authors.initials: P
authors.lastname: Bruzzi
authors.forename: Francesco
authors.initials: F
authors.lastname: Frassoni
authors.forename: Michele
authors.initials: M
authors.lastname: Piana
authors.forename: Gianmario
authors.initials: G
authors.lastname: Sambuceti
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001842:Bone and Bones / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000000981:diagnostic imaging / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods; D051598:Whole Body Imaging / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18