PURPOSE - Determine if skeletal tumor burden on F-fluoride PET/CT (fluoride PET/CT) predicts the risk of bone marrow failure (BMF) after Ra dichloride therapy (Ra).
METHODS - Forty-one metastatic prostate cancer patients (43-89 years old; mean, 71 ± 9 years.
) underwent fluoride PET/CT prior to Ra. 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 Ra 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 Ra 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 - Ra 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 Ra and which will develop BMF.
Clinical nuclear medicine. 2016 Jan 30 [Epub ahead of print]
Elba C Etchebehere, John C Araujo, Denái R Milton, William D Erwin, Richard E Wendt, Nancy M Swanston, Patricia Fox, Homer A Macapinlac, Eric M Rohren
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.