title: Prediction of PSA Progression in Castration-Resistant Prostate Cancer Based on Treatment-Associated Change in Tumor Burden Quantified by 18F-Fluorocholine PET/CT.
abstract: Measurements of metabolically active tumor volume (MATV) can be applied to (18)F-fluorocholine PET/CT to quantify whole-body tumor burden. This study evaluated the serial application of these measurements as systemic treatment response markers and predictors of disease progression in patients with castration-resistant prostate cancer (CRPC).
  
  
  
  Forty-two patients completed sequential (18)F-fluorocholine PET/CT scans before and 1-3 mo after starting treatment for CRPC. Whole-body tumor segmentation was applied to determine net MATV from each scan. Changes in net MATV were evaluated as predictors of time to prostate-specific antigen (PSA) progression by Kaplan-Meier and proportional hazards regression analysis.
  
  
  
  Treatments consisted of chemotherapy in 16 patients, antiandrogens in 19 patients, (223)Ra-dichloride in 5 patients, and sipuleucel-T in 2 patients. A significant MATV response (defined as a ≥30% decrease in net MATV) was observed in 20 patients on the basis of in-treatment PET/CT performed an average of 51 d (median, 49 d) into treatment. Significantly longer times to PSA progression were observed in patients who exhibited an MATV response (418 d vs. 116 d, P = 0.0067). MATV response was associated with a hazard ratio of 0.246 (P = 0.0113) for PSA progression, which remained significant when adjusted for treatment type.
  
  
  
  Significant changes in whole-body tumor burden can be measured on (18)F-fluorocholine PET/CT over the course of contemporary treatments for CRPC. In this study, these changes were found to be predictive of PSA progression as a potential surrogate marker of treatment outcome. Because (18)F-fluorocholine PET/CT can also be used for localizing resistant tumors, this modality can potentially complement other measures of response in the precision management of advanced prostate cancer.
authors.affiliation: Oncology Research Program, Queen's Medical Center, Honolulu, Hawaii Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Joohee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Oncology Research Program, Queen's Medical Center, Honolulu, Hawaii.
authors.forename: Miles M
authors.initials: MM
authors.lastname: Sato
authors.affiliation: Hamamatsu/Queen's PET Imaging Center, Queen's Medical Center, Honolulu, Hawaii; and.
authors.forename: Marc N
authors.initials: MN
authors.lastname: Coel
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: Kyung-Han
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Hamamatsu/Queen's PET Imaging Center, Queen's Medical Center, Honolulu, Hawaii; and Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii kwee@hawaii.edu.
authors.forename: Sandi A
authors.initials: SA
authors.lastname: Kwee
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D019496:Cancer Vaccines / Q000627:therapeutic use; D002794:Choline / Q000031:analogs & derivatives*; D003131:Combined Modality Therapy; D018450:Disease Progression; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011446:Prospective Studies; D017430:Prostate-Specific Antigen / Q000032:analysis*; D064129:Prostatic Neoplasms, Castration-Resistant / Q000000981:diagnostic imaging* / Q000628:therapy*; D019275:Radiopharmaceuticals; D011883:Radium / Q000627:therapeutic use; D014020:Tissue Extracts / Q000627:therapeutic use; D047368:Tumor Burden; D051598:Whole Body Imaging
chemical_list: D000726:Androgen Antagonists; D000970:Antineoplastic Agents; D019496:Cancer Vaccines; D019275:Radiopharmaceuticals; D014020:Tissue Extracts; C514960:fluorocholine; C511774:sipuleucel-T; D017430:Prostate-Specific Antigen; D002794:Choline; D011883:Radium
keywords: PET/CT; castrate resistant prostate cancer; fluorocholine; treatment response; tumor volume