Purpose: We evaluated the performance of C11-Acetate positron emission tomography/computed tomography (PET/CT) in recurrent prostate cancer patients with early and late imaging.
Patients and Methods: Forty-one patients with recurrent prostate adenocarcinoma as evidenced by a rising prostate-specific antigen (PSA) after prior definitive treatment where imaged with C11-Acetate PET/CT. Patients with prior initial prostatectomy and prior radiation were similar in number. Early post-tracer injection PET/CT imaging was performed (3 to 7 minutes, mean 4.25), with subsequent later pelvic/lower abdominal imaging (21 to 31 minutes, mean 26.6). Target lesions where identified visually and with quantitative measurements of maximal standardized uptake valve (SUV) and lesion-to-background (L/B) ratios obtained for each lesion. Analysis was performed to determine statistical significance.
Results: Twenty-eight patients had evaluable lesions in the pelvis, which could be compared across the imaging time points. Sixty lesions were detected with 12 in the prostate, 33 in lymph nodes, 7 in the peri-prostate soft tissues or seminal vesicles (SV), and 8 in the bone. Lesions involving the lymph nodes, peri-prostate soft tissues, and bone were all more visually conspicuous on the early imaging as compared to the later imaging, and demonstrated statistically significant higher maximal SUVs and L/B ratios (P < 0.001). Lesions in the intact prostate and seminal vesicles on the early images also demonstrated significantly higher maximal SUVs (P < 0.001), but the L/B ratios were similar or slightly higher on the later images with the difference not found to be statistically significant.
Conclusion: C11-Acetate positron emission tomography/computed tomography with early imaging post injection provides improved lesion detection both in terms of maximal SUV and lesion-to-background ratios for lesions involving nodes, peri-prostate soft tissues, and bone. Lesions in the prostate and seminal vesicles showed equal visual conspicuity and lesion-to-background ratios across early and later imaging. Early imaging appears optimal in the evaluation of recurrent prostate adenocarcinoma. In a larger application (300 patients) of early imaging in this patient population, C11-Acetate PET/CT demonstrates a consistently high detection rate.
Fabio D. Almeida,1,4 Chi-Kwan Yen,1,4 Steven E. Finkelstein,2,4 Larry L. Bans,2,4 Mark C. Scholz,3 Richard Y. Lam,3 Gordon L. Grado,5,6 Elisa Blackwell,1,4 Carlos Patino1,4
1Arizona Molecular Imaging Center, Phoenix, Arizona, United States; 221st Century Oncology, Scottsdale, Arizona, United States; 3Prostate Oncology Specialists, Marina Del Ray, California, United States; 4Arizona Cancer Research Alliance (ACRA); 5Southwest Oncology Centers, Scottsdale, Arizona, United States; 6Department of Radiation Oncology, University of Minnesota, Minneapolis, Minnesota, United States
Submitted October 2, 2013 - Accepted for Publication November 10, 2013
KEYWORDS: C11-Acetate positron, PET/CT
CITATION: UroToday Int J. 2013 December;6(6):art 66. http://dx.doi.org/10.3834/uij.1944-5784.2013.12.01