Prostate-Specific Antigen and Prostate-Specific Antigen Velocity as Threshold Indicators in 11C-Acetate PET/CTAC Scanning for Prostate Cancer Recurrence

• Published in: Clinical nuclear medicine 2014-09, Vol.39 (9), p.777-783
• Main Authors: Dusing, Reginald W, Peng, Warner, Lai, Sue-Min, Grado, Gordon L, Holzbeierlein, Jeffrey M, Thrasher, J Brantley, Hill, Jacqueline, Van Veldhuizen, Peter J
• Format: Article
• Language: English
• Subjects: Aged; Humans; Image Processing, Computer-Assisted; Male; Middle Aged; Multimodal Imaging; Neoplasm Recurrence, Local - blood; Neoplasm Recurrence, Local - diagnostic imaging; Original; Positron-Emission Tomography; Prostate-Specific Antigen - standards; Prostatic Neoplasms - blood; Prostatic Neoplasms - diagnostic imaging; Reference Values; Tomography, X-Ray Computed
• ISSN: 0363-9762; 1536-0229
• DOI: 10.1097/RLU.0000000000000516

PURPOSEThe aim of this study was to identify which patient characteristics are associated with the highest likelihood of positive findings on C-acetate PET/computed tomography attenuation correction (CTAC) (PET/CTAC) scan when imaging for recurrent prostate cancer. METHODSFrom 2007 to 2011, 250 C-acetate PET/CTAC scans were performed at a single institution on patients with prostate cancer recurrence after surgery, brachytherapy, or external beam radiation. Of these patients, 120 met our inclusion criteria. Logistic regression analysis was used to examine the relationship between predictability of positive findings and patients’ characteristics, such as prostate-specific antigen (PSA) level at the time of scan, PSA kinetics, Gleason score, staging, and type of treatment before scan. RESULTSIn total, 68.3% of the 120 C-acetate PET/CTAC scans were positive. The percentage of positive scans and PSA at the time of scanning and PSA velocity (PSAV) had positive correlations. The putative sensitivity and specificity were 86.6% and 65.8%, respectively, when a PSA level greater than 1.24 ng/mL was used as the threshold for scanning. The putative sensitivity and specificity were 74% and 75%, respectively, when a PSAV level greater than 1.32 ng/mL/y was used as the threshold. No significant associations were found between scan positivity and age, PSA doubling time, Gleason score, staging, or type of treatment before scanning. CONCLUSIONSThis retrospective study suggests that threshold models of PSA greater than 1.24 ng/mL or PSAV greater than 1.32 ng/mL per year are independent predictors of positive findings in C-acetate PET/CTAC imaging of recurrent prostate cancer.