title: Skeletal Tumor Burden on Baseline 18F-Fluoride PET/CT Predicts Bone Marrow Failure After 223Ra Therapy.
abstract: OBJECTIVE
  Determine if skeletal tumor burden on 18F-fluoride PET/CT (fluoride PET/CT) predicts the risk of bone marrow failure (BMF) after 223Ra dichloride therapy (223Ra).
  
  
  METHODS
  Forty-one metastatic prostate cancer patients (43-89 years old; mean, 71 ± 9 years.) underwent fluoride PET/CT prior to 223Ra. Bone marrow failure was the primary end point and was defined as (1) development of hematologic toxicity (World Health Organization grade 3 or 4) associated with no recovery after 6 weeks or (2) death due to BMF after the last 223Ra dose. Bone marrow failure was correlated to fluoride PET/CT skeletal tumor burden (TLF10 [total lesion on fluoride PET/CT with SUVmax of 10 or greater]), use of chemotherapy, serum hemoglobin concentration, serum ALP, and serum prostate-specific antigen.
  
  
  RESULTS
  The number of 223Ra cycles ranged from 2 to 6 (mean, 5). Of the 41 patients, 16 developed BMF (G3 = 12; G4 = 4). A significantly increased risk of developing BMF was observed in patients with TLF10 of 12,000 or greater (hazard ratio [HR], 11.09; P < 0.0001), hemoglobin of less than 10 g/dL (HR, 7.35; P = 0.0002), and AP > 146 UI/L (HR, 4.52; P = 0.0100). Neither concomitant (HR, 0.91; P = 0.88) nor subsequent use of chemotherapy (HR, 0.14; P = 0.84) increased the risk of BMF, nor was prostate-specific antigen greater than 10 μg/L (HR, 0.90; P = 0.86). Moreover, in a multivariable analysis, TLF10 was the only independent predictor of BMF (HR, 6.66; P = 0.0237).
  
  
  CONCLUSIONS
  223Ra was beneficial and reduced the risk of death even in patients with a high skeletal tumor burden. Fluoride PET/CT is able to determine which patients will benefit from 223Ra and which will develop BMF.
authors.affiliation: From the *Department of Nuclear Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX; †Department of Nuclear Medicine, Campinas State University, Campinas, Brazil; and Departments of ‡Genitourinary Medical Oncology, §Biostatistics, and ‖Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX.
authors.forename: Elba C
authors.initials: EC
authors.lastname: Etchebehere
authors.forename: John C
authors.initials: JC
authors.lastname: Araujo
authors.forename: Denái R
authors.initials: DR
authors.lastname: Milton
authors.forename: William D
authors.initials: WD
authors.lastname: Erwin
authors.forename: Richard E
authors.initials: RE
authors.lastname: Wendt
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Swanston
authors.forename: Patricia
authors.initials: P
authors.lastname: Fox
authors.forename: Homer A
authors.initials: HA
authors.lastname: Macapinlac
authors.forename: Eric M
authors.initials: EM
authors.lastname: Rohren
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000000981:diagnostic imaging / Q000528:radiation effects*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy / Q000556:secondary; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000532:radiotherapy; D011868:Radioisotopes / Q000009:adverse effects / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000009:adverse effects / Q000627:therapeutic use; D011878:Radiotherapy / Q000009:adverse effects*; D011883:Radium / Q000009:adverse effects / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed; D047368:Tumor Burden
chemical_list: D011868:Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; C581106:radium Ra 223 dichloride; D011883:Radium