PT  - JOURNAL ARTICLE
AU  - Joohee Lee
AU  - Miles M. Sato
AU  - Marc N. Coel
AU  - Kyung-Han Lee
AU  - Sandi A. Kwee
TI  - Prediction of PSA Progression in Castration-Resistant Prostate Cancer Based on Treatment-Associated Change in Tumor Burden Quantified by <sup>18</sup>F-Fluorocholine PET/CT
AID  - 10.2967/jnumed.115.169177
DP  - 2016 Jul 01
TA  - Journal of Nuclear Medicine
PG  - 1058--1064
VI  - 57
IP  - 7
4099  - http://jnm.snmjournals.org/content/57/7/1058.short
4100  - http://jnm.snmjournals.org/content/57/7/1058.full
SO  - J Nucl Med2016 Jul 01; 57
AB  - Measurements of metabolically active tumor volume (MATV) can be applied to 18F-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 18F-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, 223Ra-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 18F-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 18F-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.