Three-phase 18F-fluorocholine PET/CT in the evaluation of prostate cancer recurrence

Abstract

Summary Aim: Contribution of 3-phase 18F-fluorocholine PET/CT in suspected prostate cancer recurrence at early rise of PSA. Patients, methods: Retrospective analysis was performed in 47 patients after initial treatment with radiotherapy (n = 30) or surgery (n = 17). Following CT, 10 minutes list-mode PET acquisition was done over the prostate bed after injection of 300 MBq of 18F-fluorocholine. Three timeframes of 3 minutes each were reconstructed for analysis. All patients underwent subsequent whole body PET/CT. Delayed pelvic PET/CT was obtained in 36 patients. PET/CT was interpreted visually by two observers and SUVmax determined for suspicious lesions. Biopsies were obtained from 13 patients. Results: Biopsies confirmed the presence of cancer in 11 of 13 patients with positive PET for a total of 15 local recurrences in which average SUVmax increased during 14 minutes post injection and marginally decreased in delayed scanning. Conversely inguinal lymph nodes with mild to moderate metabolic activity on PET showed a clearly different pattern with decreasing SUVmax on dynamic images. Three-phase PET/CT contributed to the diagnostic assessment of 10 of 47 patients with biological evidence of recurrence of cancer. It notably allowed the discrimination of confounding blood pool or urinary activity from suspicious hyperactivities. PET/CT was positive in all patients with PSA ≥ 2 ng/ml (n = 34) and in 4/13 patients presenting PSA values <2 ng/ml. Conclusion: 18F-fluorocholine 3-phase PET/CT showed a progressively increasing SUVmax in biopsy confirmed cancer lesions up to 14 minutes post injection while decreasing in inguinal lymph nodes interpreted as benign. Furthermore, it was very useful in differentiating local recurrences from confounding blood pool and urinary activity.

18F-fluorocholine for prostate cancer imaging: a systematic review of the literature

“…Seven studies detailing the radiosynthesis of 18 F-FCH, preclinical and early clinical dosimetry and biodistribution in humans were identified. [20][21][22][23][24][25][26] Clinical studies included six articles for evaluation of local disease, [27][28][29][30][31][32] five articles for evaluation of nodal disease, 30,[33][34][35][36] six articles for bone metastases, including evaluation of treatment response, 30,34,[37][38][39][40] 12 articles for biochemical recurrence 34,[36][37][38][40][41][42][43][44][45][46][47] and two articles evaluating 18 F-FCH in castrate-resistant patients. 39,48 Seven studies evaluated 18 F-FCH for defining intra-prostatic lesions or limited lymph node recurrence for dose-escalated radiotherapy.…”

“…20,21,24,34,35,37,38,42,57 Early time points for imaging (0-15 min post-intravenous injection) and/or delayed imaging time points (30,40,45,60, 90-120 and 65-200 min post-intravenous injection) have been also described in the published literature. 22,23,[27][28][29][30][31][32][33]36,39,40,41,[43][44][45][46][47][48][49][50][51][52][54][55][56] 34 16…”

“…In the setting of biochemical recurrence, generally the performance of 18 F-FCH PET/CT seems to be higher among patients with higher PSA at the time of recurrence, shorter PSA doubling time or higher initial Gleason grade. 34,[36][37][38][41][42][43][44][45][46][47] For instance, Cimitan et al 41 found positive 18 F-FCH scans in 54 patients examined for rising PSA post-radical prostatectomy (n ¼ 58), radical radiotherapy (n ¼ 21) or while on hormones (n ¼ 21). They noted that the 18 F-FCH scans were rarely (3/38) positive among patients with PSA o4 ng ml À1 and initial Gleason grade p7, whereas all patients with a PSA 44 ng ml À1 and Gleason score 47 had positive scans.…”

“…40 Although the overall sensitivity for detecting any recurrence with 18 F-FCH imaging at PSA levels X2-5 ng ml À1 seems to be acceptable (X80%), the sensitivity for detection of prostate bed and small lymph node recurrences at PSA levels o2-5 ng ml À1 is lower (E50%). 34,[41][42][43][44][45] This may reflect the fact that isolated local recurrence is more likely at lower PSA levels and these recurrences may be more difficult to detect owing to challenges in distinguishing between prostate bed uptake and bladder accumulation of tracer, particularly for small volume recurrences. 34,36,[41][42][43][44][45] For example, in a series of 84 PCa patients, Panebianco et al 46 noted superior performance of 3 T combined 1 H-MRI and MR spectroscopy vs 18 F-FCH PET/CT for small volume (mean diameter ¼ 6 mm) and low PSA value (0.2-2 ng ml À1 ) recurrences, but comparable performance for larger volume local recurrence (mean diameter ¼ 13.3 mm).…”

“…Lower sensitivity for detection of recurrence in PCa patients with lower PSA values (o2-5 ng ml À1 ), and small lesions (o10 mm). Steiner et al 44 47 0.4-37.7 w PET/CT Beheshti et al 37 21 56±64* PET/CT 3. In PCa patients under hormone therapy, 18 F-fluorocholine for prostate cancer imaging G Bauman et al have one or two dominant intra-prostatic lesions (DILs) suggest lesions that could serve as a target for focal dose escalation.…”