title: Extraction of223Radium by haemodialysis after treatment of metastatic castration-resistant prostate cancer.
abstract: OBJECTIVE
  223Radium-dichloride (223Ra) administration is an upcoming therapeutic option in patients with castration-resistant metastatic prostate cancer (mCRPC), whose renal and faecal excretion of223Ra has been primarily estimated from data of a phase-I clinical trial in patients with normal renal function. In the rare case of concomitant renal insufficiency requiring haemodialysis (HD), an estimation of the contamination of dialysate would be beneficial.
  
  
  METHODS
  The excretion of223Ra and its concentration in the dialysate in a patient with mCRPC and end-stage renal disease was examined for six consecutive treatment cycles. Dialysate samples were measured using a commercial system with NaI-scintillation detector.
  
  
  RESULTS
  HD showed a residual activity level in the remaining dialysate. The excreted activity was a median of 46.1 kBq (range = 42.0- 83.4 kBq) and 11.2 kBq (range = 8.4- 19.9 kBq) for the first (24 h post injection p.i.) and second HD (96 h p.i.), respectively. The activity concentration decreased significantly from a median of 4.18 kBq/l (range = 2.98-5.14 kBq/l) to 0.85 kBq/l (range = 0.69- 1.31 kBq/l, p < 0.0001). For all consecutive time points, the activity concentration further decreased significantly (p < 0.0001). The activity concentration of dialysate from HD performed 125.4 h p.i. [95 % confidence interval = 120.5-130.4 h p.i.] reached the threshold for unrestricted waste disposal.
  
  
  CONCLUSIONS
  The observed extraction of223Ra by HD exceeded the data determined from the phase-I study. The activity concentration in the dialysate observed for the first HD's p.i. was above the threshold for unrestricted disposal of radioactive waste in Germany. Therefore, the specific requirement for waste handling has to be followed to fulfil the radiation protection regulations.
authors.affiliation: Oliver Stephan Großer, PhD, Klinik für Radiologie und Nuklearmedizin, Universitätsklinikum Magdeburg, Leipziger Straße 44, 39120 Magdeburg, Germany, Tel: +49 391 67 13000, Fax: +49 391 67 13990, E-Mail: oliver.grosser@med.ovgu.de.
authors.forename: Oliver Stephan
authors.initials: OS
authors.lastname: Großer
authors.forename: Heiko
authors.initials: H
authors.lastname: Wissel
authors.forename: Thekla
authors.initials: T
authors.lastname: Wallbaum
authors.forename: Philipp
authors.initials: P
authors.lastname: Genseke
authors.forename: Dennis
authors.initials: D
authors.lastname: Kupitz
authors.forename: Jens
authors.initials: J
authors.lastname: Ricke
authors.forename: Juri
authors.initials: J
authors.lastname: Ruf
authors.forename: Holger
authors.initials: H
authors.lastname: Amthauer
mesh_terms: D001781:Blood Component Removal / Q000379:methods; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary*; D015314:Dialysis Solutions / Q000032:analysis / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D064129:Prostatic Neoplasms, Castration-Resistant / Q000473:pathology* / Q000532:radiotherapy*; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods; D011868:Radioisotopes / Q000097:blood / Q000302:isolation & purification / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000097:blood / Q000302:isolation & purification / Q000627:therapeutic use; D011883:Radium / Q000097:blood / Q000302:isolation & purification* / Q000627:therapeutic use*; D006435:Renal Dialysis / Q000379:methods*; D016896:Treatment Outcome
chemical_list: D015314:Dialysis Solutions; D011868:Radioisotopes; D019275:Radiopharmaceuticals; C581106:radium Ra 223 dichloride; D011883:Radium
keywords: castration-resistant metastatic prostate cancer; dialysis; radium-223