title: 33% radius evaluation to assess bone mineral density in prostate cancer patients.
abstract: OBJECTIVE
  Dual-energy X-ray absorptiometry (DXA) is the standard method to assess bone mineral density (BMD). The International Society for Clinical Densitometry recommends the measurement of BMD at lumbar spine, total hip and femoral neck, but in certain circumstances the 33% radius may be the recommended area to measure BMD. The aim of this study has been to analyze whether 33% radius should be considered the recommended area to assess BMD in prostate cancer patients.
  
  
  METHODS
  This is a retrospective study where BMD was assessed by DXA at 33% radius, lumbar spine, total hip, and femoral neck (cDXA) in 141 prostate cancer patients. Twenty-eight patients were hormone naïve while 113 were subjected to androgen suppression (AS) during the mean period of 29 months. Osteoporosis was diagnosed when T-score was lower than -2.5 and osteopenia when it ranged between -1 and -2.5.
  
  
  RESULTS
  The osteoporosis rate was 29.8% at 33% radius, 23.4% at femoral neck, 19.9% at lumbar spine, and 12.8% at total hip. The overall osteoporosis rate at cDXA was 29.1%. Osteoporosis was detected in 52.2% at 33% radius and 36.2% at cDXA. Normal BMD was found in 17.7% at 33% radius and 34.8% at cDXA. The 33% radius was the only site where a significant increase in the osteoporosis rate was detected in patients subjected to AS compared to those hormone naïve (33 and 13.8%).
  
  
  CONCLUSIONS
  The 33% radius seems more sensible than the central skeleton areas to detect bone mass loss in patients with prostate cancer.
authors.affiliation: Department of Urology, Vall d´Hebron Hospital, Autónoma University Medical School of Barcelona, Po Vall d'Hebron, 119-129, 08035, Barcelona, Spain. jmorote@vhebron.net
authors.forename: Juan
authors.initials: J
authors.lastname: Morote
authors.forename: Jacques
authors.initials: J
authors.lastname: Planas
authors.forename: Maria Carmen
authors.initials: MC
authors.lastname: Mir
authors.forename: Carles X
authors.initials: CX
authors.lastname: Raventós
authors.forename: Gloria
authors.initials: G
authors.lastname: Encabo
authors.forename: Andreas
authors.initials: A
authors.lastname: Doll
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000494:pharmacology / Q000627:therapeutic use; D000728:Androgens / Q000378:metabolism; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D005272:Femur Neck / Q000378:metabolism / Q000503:physiopathology; D006621:Hip Joint / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D008159:Lumbar Vertebrae / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis* / Q000378:metabolism / Q000503:physiopathology*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D011884:Radius / Q000378:metabolism / Q000503:physiopathology*; D012189:Retrospective Studies
chemical_list: D000726:Androgen Antagonists; D000728:Androgens