Prediction of PSA Progression in Castration-Resistant Prostate Cancer Based on Treatment-Associated Change in Tumor Burden Quantified by 18F-Fluorocholine PET/CT

J Nucl Med. 2016 Jul;57(7):1058-64. doi: 10.2967/jnumed.115.169177. Epub 2016 Feb 16.

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).

Methods: 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.

Results: 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.

Conclusion: 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.

Trial registration: ClinicalTrials.gov NCT00928174 NCT00928252.

Keywords: PET/CT; castrate resistant prostate cancer; fluorocholine; treatment response; tumor volume.

MeSH terms

  • Aged
  • Androgen Antagonists / therapeutic use
  • Antineoplastic Agents / therapeutic use
  • Cancer Vaccines / therapeutic use
  • Choline / analogs & derivatives*
  • Combined Modality Therapy
  • Disease Progression
  • Humans
  • Kaplan-Meier Estimate
  • Male
  • Positron Emission Tomography Computed Tomography / methods*
  • Prospective Studies
  • Prostate-Specific Antigen / analysis*
  • Prostatic Neoplasms, Castration-Resistant / diagnostic imaging*
  • Prostatic Neoplasms, Castration-Resistant / therapy*
  • Radiopharmaceuticals*
  • Radium / therapeutic use
  • Tissue Extracts / therapeutic use
  • Tumor Burden
  • Whole Body Imaging

Substances

  • Androgen Antagonists
  • Antineoplastic Agents
  • Cancer Vaccines
  • Radiopharmaceuticals
  • Tissue Extracts
  • fluorocholine
  • sipuleucel-T
  • Prostate-Specific Antigen
  • Choline
  • Radium

Associated data

  • ClinicalTrials.gov/NCT00928174
  • ClinicalTrials.gov/NCT00928252