title: Prostate cancer bone metastases on staging prostate MRI: prevalence and clinical features associated with their diagnosis.
abstract: Bone lesions on prostate MRI often raise concern about metastases. This study aimed to evaluate the prevalence of bone metastases on staging prostate MRI and evaluate associations between their MRI features and clinical/pathologic characteristics.
  
  
  
  Retrospective, IRB-approved study of 3765 patients undergoing prostate MRI for newly diagnosed PCa between 2000 and 2014. The reference standard to calculate the prevalence of bone metastases was bone biopsy and/or ≥1-year follow-up after MRI. In a subsample of 228 patients, the MRI characteristics of bone lesions were recorded by two radiologists independently. Associations between MRI and clinical/pathologic findings, including National Comprehensive Cancer Network (NCCN) risk categories, were calculated.
  
  
  
  57/3765 patients (1.5%, 95% CI 1.2-2.0%) had bone metastases. No patient with NCCN low-risk PCa (Gleason < 7, PSA < 10 ng/mL, cT1-2a) had bone metastases. In the subsample, ≥1 bone lesion was present on MRI in 74% (95% CI 0.67-0.79) and 72% (95% CI 0.66-0.78) of patients (R1 and R2). Larger lesion diameter (OR 1.33/1.19; p < 0.001 for both readers) and the absence of intralesional fat (OR 0.07/0.11; p = 0.004/0.002 for R1/R2) were significantly associated with bone metastases.
  
  
  
  Bone lesions are common in prostate MRI, but only rarely represent metastases. MRI should be interpreted in the context of clinical features that influence the likelihood of metastatic disease.
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA. vargasah@mskcc.org.|, 1275 York Av, Room C278, New York, NY, 10021, USA. vargasah@mskcc.org.
authors.forename: Hebert Alberto
authors.initials: HA
authors.lastname: Vargas
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Schor-Bardach
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Niamh
authors.initials: N
authors.lastname: Long
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Anna N
authors.initials: AN
authors.lastname: Kirzner
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Jane D
authors.initials: JD
authors.lastname: Cunningham
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Debra A
authors.initials: DA
authors.lastname: Goldman
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Chaya S
authors.initials: CS
authors.lastname: Moskowitz
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Ramon E
authors.initials: RE
authors.lastname: Sosa
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Evis
authors.initials: E
authors.lastname: Sala
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Panicek
authors.affiliation: Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, NY, 10065, USA.
authors.forename: Hedvig
authors.initials: H
authors.lastname: Hricak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000556:secondary*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D015995:Prevalence; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D012189:Retrospective Studies
keywords: Bone metastases; Detection; Imaging; MRI; Prostate cancer; Staging