title: Factors affecting (223)Ra therapy: clinical experience after 532 cycles from a single institution.
abstract: OBJECTIVE
  The aim of this study was to identify baseline features that predict outcome in (223)Ra therapy.
  
  
  METHODS
  We retrospectively reviewed 110 patients with metastatic castration-resistant prostate cancer treated with (223)Ra. End points were overall survival (OS), progression-free survival (PFS), bone event-free survival (BeFS), and bone marrow failure (BMF). The following parameters were evaluated prior to the first (223)Ra cycle: serum levels of hemoglobin (Hb), prostate-specific antigen (PSA), alkaline phosphatase (ALP), Eastern Cooperative Oncology Group (ECOG) status, pain score, use of chemotherapy, and external beam radiation therapy (EBRT). During/after (223)Ra we evaluated: the total number of radium cycles (RaTot), the PSA doubling time (PSADT), and the use of chemotherapy, EBRT, abiraterone, and enzalutamide.
  
  
  RESULTS
  A significant reduction of ALP (p < 0.001) and pain score (p = 0.041) occurred throughout the (223) Ra cycles. The risk of progression was associated with declining ECOG status [hazard ratio (HR) = 3.79; p < 0.001] and decrease in PSADT (HR = 8.22; p < 0.001). RaTot, ALP, initial ECOG status, initial pain score, and use of abiraterone were associated with OS (p ≤ 0.008), PFS (p ≤ 0.003), and BeFS (p ≤ 0.020). RaTot, ALP, initial ECOG status, and initial pain score were significantly associated with BMF (p ≤ 0.001) as well as Hb (p < 0.001) and EBRT (p = 0.009). On multivariable analysis, only RaTot and abiraterone remained significantly associated with OS (p < 0.001; p = 0.033, respectively), PFS (p < 0.001; p = 0.041, respectively), and BeFS (p < 0.001; p = 0.019, respectively). Additionally, RaTot (p = 0.027) and EBRT (p = 0.013) remained significantly associated with BMF.
  
  
  CONCLUSIONS
  Concomitant use of abiraterone and (223)Ra seems to have a beneficial effect, while the EBRT may increase the risk of BMF.
authors.affiliation: Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, 1400 Pressler, FCT 16.6005, Unit 1483, Houston, TX, 77030, USA. elba.etchebehere@gmail.com.|Department of Nuclear Medicine, Campinas State University (Unicamp), Rua Vital Brasil, 251, Cx.Postal. 6142, Cidade Universitária Zeferino Vaz, 13083-888, Campinas, Brazil. elba.etchebehere@gmail.com.
authors.forename: Elba C
authors.initials: EC
authors.lastname: Etchebehere
authors.affiliation: Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: Denái R
authors.initials: DR
authors.lastname: Milton
authors.affiliation: Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Araujo
authors.affiliation: Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, 1400 Pressler, FCT 16.6005, Unit 1483, Houston, TX, 77030, USA.
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Swanston
authors.affiliation: Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, 1400 Pressler, FCT 16.6005, Unit 1483, Houston, TX, 77030, USA.
authors.forename: Homer A
authors.initials: HA
authors.lastname: Macapinlac
authors.affiliation: Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, 1400 Pressler, FCT 16.6005, Unit 1483, Houston, TX, 77030, USA.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Rohren
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D006801:Humans; D008297:Male; D008875:Middle Aged; D064129:Prostatic Neoplasms, Castration-Resistant / Q000473:pathology / Q000532:radiotherapy*; D011883:Radium / Q000009:adverse effects / Q000627:therapeutic use*; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D011883:Radium
keywords: 223Ra; Abiraterone; Bone marrow failure; External beam radiation therapy; PSA; Prostate cancer