title: Is ¹⁵³Samarium-ethylene-diamine-tetramethyl-phosphonate (EDTMP) bone uptake influenced by bisphosphonates in patients with castration-resistant prostate cancer?
abstract: OBJECTIVE
  To evaluate the impact of biphosphonate administration on subsequent (153)Samarium-ethylene-diamine-tetramethyl-phosphonate (EDTMP) uptake in bone metastases of patients with castration-resistant prostate cancer.
  
  
  METHODS
  The bone uptake of (153)Sm-EDTMP was assessed in 40 consecutive patients with castration-resistant prostate cancer and multiple painful bone metastases and no prior bisphosphonate therapy. (153)Sm-EDTMP was repeated after 3 months in the presence of bisphosphonates (zoledronic acid every 4 weeks, first administration 1 week after (153)Sm-EDTMP administration). The retained activity in bone was evaluated 20 h after application using whole-body scintigraphy (acquisition 15 cm/min).
  
  
  RESULTS
  Mean patient age was 69 ± 4.8 years (range 57-77 years). Mean PSA level at study entry was 18.2 ± 21.0 ng/ml. (153)Sm-EDTMP uptake ranged from 36.3 to 75.3% (mean 55.1 ± 10.9%) before bisphosphonate administration and 35.6 to 73.3% (mean 55.2 ± 10.4%) after bisphosphonate administration. No significant intra-individual difference with or without bisphosphonate treatment was observed (P = 0.647).
  
  
  CONCLUSIONS
  Bisphosphonate treatment does not affect (153)Sm-EDTMP bone uptake in patients with castration-resistant metastatic prostate cancer. Thus, bisphosphonate treatment can be continued safely during samarium therapy.
authors.affiliation: Department of Urology, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria. matthias.waldert@meduniwien.ac.at
authors.forename: Matthias
authors.initials: M
authors.lastname: Waldert
authors.forename: Tobias
authors.initials: T
authors.lastname: Klatte
authors.forename: Mesut
authors.initials: M
authors.lastname: Remzi
authors.forename: Helmut
authors.initials: H
authors.lastname: Sinzinger
authors.forename: Christian
authors.initials: C
authors.lastname: Kratzik
mesh_terms: D000368:Aged; D018712:Analgesics, Non-Narcotic / Q000493:pharmacokinetics*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000150:complications / Q000556:secondary; D004164:Diphosphonates / Q000627:therapeutic use*; D004347:Drug Interactions; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000188:drug therapy* / Q000209:etiology; D009919:Orchiectomy; D009942:Organometallic Compounds / Q000493:pharmacokinetics*; D009943:Organophosphorus Compounds / Q000493:pharmacokinetics*; D011471:Prostatic Neoplasms / Q000188:drug therapy / Q000473:pathology*; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D012189:Retrospective Studies; D000077211:Zoledronic Acid
chemical_list: D018712:Analgesics, Non-Narcotic; D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D019275:Radiopharmaceuticals; D000077211:Zoledronic Acid; C061972:samarium Sm-153 lexidronam