Detection of recurrent prostate cancer with 18F-fluorocholine PET/CT in relation to PSA level at the time of imaging

Annals of Nuclear Medicine, Jul 2012

Purpose To evaluate fluorine-18 fluorocholine (FCH) PET/CT for the detection of recurrent prostate cancer in relation to prostate-specific antigen (PSA) level. Methods FCH PET/CT was performed in 50 patients with rising PSA levels at follow-up of primary treatment of prostate cancer (radical prostatectomy in 28, radiation therapy in 13, and brachytherapy in 9). PET detection rates were determined at various PSA thresholds and examined by receiver operating characteristic analysis. Results Findings consistent with recurrent prostate cancer were noted on FCH PET/CT in 31/50 (62 %) patients, with positive findings in 17/18 (94 %), and 11/13 (85 %), 2/7 (29 %), and 1/12 (8 %) patients with PSA >4, >2–4, >0.5–2, and ≤0.5 ng/mL, respectively. These findings were indicative of local/regional recurrence in 23 cases and systemic recurrence in 8 cases, with only a single route of recurrence (i.e., either hematogenous, lymphatic, or intraprostatic) in 84 % of PET scans with positive findings. Abnormal tumor activity was detected in 88 % of patients with a PSA level of 1.1 ng/mL or higher, and in only 6 % of patients with a PSA level below this threshold value. Conclusion FCH PET/CT may serve to identify the route of tumor progression in patients with recurrent prostate cancer; however, the likelihood of tumor detection may be related to the PSA level at the time of imaging.

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Detection of recurrent prostate cancer with 18F-fluorocholine PET/CT in relation to PSA level at the time of imaging

Sandi A. Kwee 0 1 Marc N. Coel 0 1 John Lim 0 1 0 S. A. Kwee Department of Medicine, John A. Burns School of Medicine, University of Hawaii at Manoa , Honolulu, HI, USA 1 S. A. Kwee (&) M. N. Coel J. Lim Hamamatsu/Queen's PET Imaging Center, The Queen's Medical Center , 1301 Punchbowl St., Honolulu, HI 96813, USA Purpose To evaluate fluorine-18 fluorocholine (FCH) PET/CT for the detection of recurrent prostate cancer in relation to prostate-specific antigen (PSA) level. Methods FCH PET/CT was performed in 50 patients with rising PSA levels at follow-up of primary treatment of prostate cancer (radical prostatectomy in 28, radiation therapy in 13, and brachytherapy in 9). PET detection rates were determined at various PSA thresholds and examined by receiver operating characteristic analysis. Results Findings consistent with recurrent prostate cancer were noted on FCH PET/CT in 31/50 (62 %) patients, with positive findings in 17/18 (94 %), and 11/13 (85 %), 2/7 (29 %), and 1/12 (8 %) patients with PSA [4, [2-4, [0.5-2, and B0.5 ng/mL, respectively. These findings were indicative of local/regional recurrence in 23 cases and systemic recurrence in 8 cases, with only a single route of recurrence (i.e., either hematogenous, lymphatic, or intraprostatic) in 84 % of PET scans with positive findings. Abnormal tumor activity was detected in 88 % of patients with a PSA level of 1.1 ng/mL or higher, and in only 6 % of patients with a PSA level below this threshold value. Conclusion FCH PET/CT may serve to identify the route of tumor progression in patients with recurrent prostate cancer; however, the likelihood of tumor detection may be related to the PSA level at the time of imaging. - A rising serum prostate-specific antigen (PSA) level is often the first indicator of recurrent disease in patients with prostate cancer treated with radiation therapy (RT) or radical prostatectomy (RP). At 5 years following such primary treatments, rising PSA levels can be detected in approximately 1520 % of low-risk patients, and approximately 50 % of high-risk (i.e., Gleason score 810, PSA [20 ng/mL, stage T3) patients [1, 2]. Localizing recurrent tumors in these patients has proven to be a significant challenge when using conventional diagnostic imaging, particularly when the PSA level has not yet risen substantially [35]. While recurrence patterns in prostate cancer are known to vary by treatment [6, 7], awareness of these patterns is not sufficient to support the customization of salvage therapy for recurrent prostate cancer. Patientindividualized treatment approaches for recurrent prostate cancer could be enhanced if tumor spread along local, lymphatic, and hematogenous routes are correctly identified shortly after a rise in PSA is detected. PET imaging using tracer analogs of choline has shown significant promise for detecting prostate cancer [813]. The rationale for using choline derivatives as oncologic PET tracers is based on the observation that choline transport and phosphorylation are upregulated in most cancers, including prostate cancer [1417]. While there are some data on the performance of choline-based PET imaging for whole-body staging of prostate cancer, some uncertainty remains as to its diagnostic sensitivity in patients with low levels of PSA following RP, external beam RT, and interstitial brachytherapy. The purpose of this study is to evaluate the detection rate of FCH PET/CT in patients with rising PSA levels following primary treatment of prostate cancer, paying particular attention to the routes of tumor progression that can be identified as well as the potential relationship between PSA level and tumor detection. Fifty sequential patients with a history of clinically localized prostate cancer who were noted to have an elevated PSA level [0.2 ng/mL on at least two serial measurements after completion of RP, RT, or interstitial brachytherapy were recruited to undergo FCH PET/CT imaging in this institutional review board-approved clinical research study. All patients gave written informed consent before their participation. Hormone-nave patients as well as patients who received luteinizing hormone-releasing hormone (LHRH) agonist therapy for at least 3 months prior to the detection of an elevated PSA, including those treated with an LHRH agonist in conjunction with primary treatment, were eligible for this study. However, patients in whom LHRH agonist therapy was started recently, namely within 3 months, or following the detection of an elevated PSA level were excluded from the study. Radiopharmaceutical synthesis and PET imaging FCH synthesis was performed by fluorination of ditosylmethane with fluorine-18 followed by alkylation of the fluorotosylmethane intermediate with dimethylethanolamine using a chemical process control unit (CTI/Siemens CPCU, CTI/Siemens, Knoxville, TN) [18]. All synthesis products passed standard assays for radiochemical purity, radionuclidic identity, chemical purity, and pyrogeni (...truncated)


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Sandi A. Kwee, Marc N. Coel, John Lim. Detection of recurrent prostate cancer with 18F-fluorocholine PET/CT in relation to PSA level at the time of imaging, Annals of Nuclear Medicine, 2012, pp. 501-507, Volume 26, Issue 6, DOI: 10.1007/s12149-012-0601-8