(11)C-Choline PET/CT in patients with hormone-resistant prostate cancer showing biochemical relapse after radical prostatectomy - Abstract

PURPOSE: To determine the diagnostic efficacy of 11C-choline PET/CT in patients with prostate cancer (PC) after radical prostatectomy who presented with increasing PSA levels during follow-up in spite of being on hormone treatment (HT), and therefore showing HT resistance.

METHODS: We evaluated a large series of 157 consecutive PC patients previously treated by radical prostatectomy who presented with biochemical recurrence with increasing PSA levels in spite of ongoing HT (HT-resistant patients). At the time of 11C-choline PET/CT, the mean value of trigger PSA level was 8.3 (range  0.2 - 60.6 ng/mL), the mean PSA doubling time (PSAdt) was 5.3  (range  0.4 - 35 months), and the mean PSA velocity (PSAvel) was 22.1 ng/mL/year (range 0.12 - 82 ng/mL/year). 11C-Choline PET/CT was performed following a standard procedure at our centre to investigate increasing PSA levels, either as the first imaging procedure or in patients with negative conventional imaging. At the time of 11C-choline PET/CT all patients were receiving HT (61 were receiving monotherapy and 96 multidrug therapy). PET-positive findings were validated by: (a) transrectal US-guided biopsy in patients with recurrence in the prostatic bed, (b) surgical pelvic lymphadenectomy, (c) other imaging modalities, including repeated 11C-choline PET/CT, performed during a minimum follow-up of 12-months.

RESULTS: 11C-Choline PET/CT showed positive findings in 104 of the 157 patients (66 %). 11C-choline PET/CT detected: a single lesion in 40 patients (7 in the prostate bed, 10 in lymph nodes, 22 in bone, 1 at another site); two lesions in 18 patients (7 in lymph nodes, 7 in bone, 4 in both lymph nodes and bone); three or four lesions in 7 patients (4 in lymph nodes, 2 in bone, 1 at another site); and more than four lesions in the remaining 39 patients (2 in the prostate bed, 12 in lymph nodes, 12 in bone, 11 in both lymph nodes and bone, 2 at other sites). In 11C-choline PET-negative patients, the mean values of trigger PSA, PSAdt and PSAvel were 3.8 ng/mL (range 0.2 - 11.9 ng/mL) 7.0 months (range 1.21 - 35 months) and 5.8 ng/mL/year (range 0.12 - 30.1) respectively, while in 11C-Choline-PET-positive patients they were 10.5 ng/mL (range 0.2 - 60.6), 4.4 months (range 0.4 - 19.7) and 15.9 ng/mL/year (range 0.5 - 82.0) respectively. The differences between PET-negative and PET-positive patients were statistically significant for all these parameters: trigger PSA, p < 0.01; PSAdt, p < 0.01; PSAvel, p = 0.03.

CONCLUSION: In our patient population, 11C-choline PET/CT was able to detect relapsed disease in a large proportion of HT-resistant PC patients during HT. These data, obtained in a large series, suggest that HT withdrawal before performing a 11C-choline PET/CT scan may not be necessary for the detection of recurrent disease if PSA levels are increasing and PSA kinetics are rapid.

Written by:
Ceci F, Castellucci P, Mamede M, Schiavina R, Rubello D, Fuccio C, Ambrosini V, Boschi S, Martorana G, Fanti S.   Are you the author?
Nuclear Medicine Unit, Department of Haematology Oncology and Laboratory Medicine, Azienda Ospedaliero-Universitaria di Bologna, Policlinico Sant'Orsola-Malpighi, University of Bologna, Bologna, Italy.

Reference: Eur J Nucl Med Mol Imaging. 2012 Nov 14. Epub ahead of print.
doi: 10.1007/s00259-012-2272-z

PubMed Abstract
PMID: 23151910

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