Purpose. To determine the clinical significance of unexpected, abnormal FDG uptake in the prostate in patients undergoing FDG-PET/CT for staging of other primary malignancies without a prior history of prostate carcinoma. Methods. Retrospective search of FDG-PET/CT studies to identify patients with unexpected, abnormal FDG uptake in the prostate gland, who underwent subsequent biopsy, was performed. 26 patients were identified. Images were reviewed to determine the pattern of uptake within the prostate (focal or diffuse) and maximum standardized uptake value (SUVmax). PSA and Gleason scores were recorded. Results. 15/26 (58%) patients were found to have prostate carcinoma. Gleason scores ranged from 6 to 9.9. There was no statistical difference in the pattern of uptake (focal versus diffuse) or the SUVmax. Serum PSA levels with cancer (range, 2–26.8？ng; mean, 10.2？ng) and those without cancer (range, 2–10.5？ng; mean, 2.2？ng) were statistically significant ( , Wilcoxon rank sum test). Conclusions. Patients with abnormal uptake in the prostate have a 58% likelihood of occult prostate cancer. In the setting of elevated serum PSA levels, abnormal prostate uptake should therefore be viewed with suspicion and a urology consult should be obtained; however, it is irrelevant in patients with underlying aggressive malignancies. 1. Introduction Prostate cancer causes more deaths than any other cancer in men aged 55 to 74 years in many industrialized countries [1], and it is diagnosed incidentally in up to 28% of patients. The median age at diagnosis of prostate cancer is 67 years [2]. Prostate cancer is often regarded as an indolent malignancy and a disease that evolves over many years with aging; the premise for detecting and treating prostate cancer is a subject of debate. Currently serial elevation of serum prostate-specific antigen (PSA) levels and an abnormal digital rectal exam raise the suspicion for prostate cancer. Fluorodeoxyglucose (F-18 FDG) positron emission tomography (PET/CT) is an imaging modality that is, increasingly, being used for assessing cancer stage, response to therapy, and surveillance after treatment in various malignancies. Incidental uptake of FDG is occasionally noted within the prostate [3]; whether this finding is associated with prostate cancer or not is not adequately established. The purpose of this study was to determine the association between “incidentally” noted FDG uptake in the prostate gland and occult prostate carcinoma. 2. Patients and Methods Institutional review board approval was obtained for this retrospective study.
References
[1]
World Health Organization, “World Health Statistics Annual 1995-1996,” Tech. Rep., WHO, Geneva, Switzerland.
[2]
S. F. Altekruse, C. L. Kosary, M. Krapcho et al., SEER Cancer Statistics Review, 1975–2007, edited by B. K. Edwards, National Cancer Institute, Bethesda, Md, USA, 2010.
[3]
E. J. Han, J. H. O, W. H. Choi, I. R. Yoo, and S. K. Chung, “Significance of incidental focal uptake in prostate on 18-fluoro-2-deoxyglucose positron emission tomography CT images,” The British Journal of Radiology, vol. 83, no. 995, pp. 915–920, 2010.
[4]
G. Wang, E. W. F. Lau, R. Shakher et al., “How do oncologists deal with incidental abnormalities on whole-body fluorine-18 fluorodeoxyglucose PET/CT?” Cancer, vol. 109, no. 1, pp. 117–124, 2007.
[5]
S. Nishizawa, S. Kojima, S. Teramukai et al., “Prospective evaluation of whole-body cancer screening with multiple modalities including [18F]fluorodeoxyglucose positron emission tomography in a healthy population: a preliminary report,” Journal of Clinical Oncology, vol. 27, no. 11, pp. 1767–1773, 2009.
[6]
M. Ide and Y. Suzuki, “Is whole-body FDG-PET valuable for health screening? For,” European Journal of Nuclear Medicine and Molecular Imaging, vol. 32, no. 3, pp. 339–341, 2005.
[7]
S. Kojima, B. Zhou, S. Teramukai et al., “Cancer screening of healthy volunteers using whole-body 18F-FDG-PET scans: the Nishidai clinic study,” European Journal of Cancer, vol. 43, no. 12, pp. 1842–1848, 2007.
[8]
Y. Y. Shen, C. T. Su, G. J. S. Chen, Y. K. Chen, A. C. F. Liao, and F. S. Tsai, “The value of 18F-fluorodeoxyglucose positron emission tomography with the additional help of tumor markers in cancer screening,” Neoplasma, vol. 50, no. 3, pp. 217–221, 2003.
[9]
M. Piert, H. Park, A. Khan et al., “Detection of aggressive primary prostate cancer with 11C-choline PET/CT using multimodality fusion techniques,” Journal of Nuclear Medicine, vol. 50, no. 10, pp. 1585–1593, 2009.
[10]
A. J. Breeuwsma, M. Rybalov, A. M. Leliveld, J. Pruim, and I. J. de Jong, “Correlation of [11C]choline PET-CT with time to treatment and disease-specific survival in men with recurrent prostate cancer after radical prostatectomy,” The Quarterly Journal of Nuclear Medicine and Molecular Imaging, vol. 56, no. 5, pp. 440–446, 2012.
[11]
R. Minamimoto, H. Uemura, F. Sano et al., “The potential of FDG-PET/CT for detecting prostate cancer in patients with an elevated serum PSA level,” Annals of Nuclear Medicine, vol. 25, no. 1, pp. 21–27, 2011.
[12]
N. Takahashi, T. Inoue, J. Lee, T. Yamaguchi, and K. Shizukuishi, “The roles of PET and PET/CT in the diagnosis and management of prostate cancer,” Oncology, vol. 72, no. 3-4, pp. 226–233, 2008.
[13]
R. Tiguert, E. L. Gheiler, M. V. Tefilli et al., “Lymph node size does not correlate with the presence of prostate cancer metastasis,” Urology, vol. 53, no. 2, pp. 367–371, 1999.
[14]
G. L. Andriole, E. D. Crawford, R. L. Grubb II, S. S. Buys, D. Chia, and T. R. Church, “Mortality results from a randomized prostate-cancer screening trial,” The New England Journal of Medicine, vol. 360, no. 13, pp. 1310–1319, 2009.
[15]
F. H. Schr？der, J. Hugosson, M. J. Roobol, T. L. Tammela, S. Ciatto, and V. Nelen, “Screening and prostate-cancer mortality in a randomized European study,” The New England Journal of Medicine, vol. 360, no. 13, pp. 1320–1328, 2009.
[16]
W. J. Catalona, J. P. Richie, J. B. DeKernion et al., “Comparison of prostate specific antigen concentration versus prostate specific antigen density in the early detection of prostate cancer: receiver operating characteristic curves,” Journal of Urology, vol. 152, no. 6, part 1, pp. 2031–2036, 1994.
[17]
I. M. Thompson, D. K. Pauler, P. J. Goodman, C. M. Tangen, M. S. Lucia, and H. L. Parnes, “Prevalence of prostate cancer among men with a prostate-specific antigen level ≤4.0？ng per milliliter,” The New England Journal of Medicine, vol. 350, no. 22, pp. 2239–2246, 2004.
[18]
S. N. Lecumberri, F. J. L. Couso, C. R. Navarro, M. G. Dorronsoro, B. L. Li？ero, and A. I. Aznar, “A study of the progression of the incidental prostate cancer depending on the kind of treatment performed,” Actas Urologicas Espanolas, vol. 31, no. 8, pp. 810–818, 2007.
[19]
S. Ahmad, F. O'Kelly, R. P. Manecksha et al., “Survival after incidental prostate cancer diagnosis at transurethral resection of prostate: 10-year outcomes,” Irish Journal of Medical Science, vol. 181, no. 1, pp. 27–31, 2012.
[20]
O. Andrèn, H. Garmo, L. Mucci, S. O. Andersson, J. E. Johansson, and K. Fall, “Incidence and mortality of incidental prostate cancer: a Swedish register-based study,” The British Journal of Cancer, vol. 100, no. 1, pp. 170–173, 2009.
[21]
D. Robinson, G. Aus, J. Bak et al., “Long-term follow-up of conservatively managed incidental carcinoma of the prostate: a multivariate analysis of prognostic factors,” Scandinavian Journal of Urology and Nephrology, vol. 41, no. 2, pp. 103–109, 2007.
[22]
A. Sruogis, A. Ulys, G. Smailyte, Z. Kardelis, and A. Kulboka, “Incidentally found prostate cancer and influence on overall survival after radical cystoprostatectomy,” Prostate Cancer, vol. 2012, Article ID 690210, 5 pages, 2012.
