Diagnostic performance of 18F-fluciclovine PET/CT for regional lymph node metastases in patients with primary prostate cancer: a multicenter phase II clinical trial.

This multicenter, phase II clinical trial evaluated the diagnostic performance of 18F-fluciclovine, a novel amino acid for positron-emission tomography (PET), for detection of small lymph node metastases with short-axis diameters of 5-10 mm in patients with prostate cancer.

Patients with prostate cancer were eligible after screening of laboratory tests and pelvic contrast-enhanced computed tomography (CT). Pelvic region 18F-fluciclovine PET/CT was then acquired within 28 days and dissection of regional lymph nodes was performed within 60 days of pelvic contrast-enhanced CT. Diagnostic performance of 18F-fluciclovine-PET/CT was evaluated by comparison with standard histopathology of lymph nodes.

In a total of 28 patients, 40 regional lymph nodes with short-axis diameters of 5-10 mm were eligible for efficacy evaluation; seven of these showed metastases confirmed by histopathology. The sensitivity of 18F-fluciclovine PET/CT was 57.1% (4/7). All four true positive lymph nodes detected by 18F-fluciclovine PET/CT had a metastatic lesion with a long-axis diameter of ≥7 mm and a high proportion of cancer volume (60-100%) according to pathology evaluation. The specificity, diagnostic accuracy, positive predictive value, and negative predictive value of 18F-fluciclovine PET/CT in lymph node-based analysis were 84.8% (28/33), 80.0% (32/40), 44.4% (4/9), and 90.3% (28/31), respectively. No clinically significant adverse events occurred.

18F-fluciclovine PET/CT detected small lymph node metastases; however it also showed positive findings in benign lymph nodes. Refinement of the image assessment criteria may improve the diagnostic performance of 18F-fluciclovine PET/CT for small lymph node metastases in patients with prostate cancer.

Japanese journal of clinical oncology. 2019 May 16 [Epub ahead of print]

Hiroyoshi Suzuki, Seishi Jinnouchi, Yasushi Kaji, Takeshi Kishida, Hidefumi Kinoshita, Seiji Yamaguchi, Toyofusa Tobe, Takehiko Okamura, Mutsushi Kawakita, Junya Furukawa, Akiharu Otaka, Yoshiyuki Kakehi

Department of Urology, Toho University Sakura Medical Center, Sakura, Japan., Atsuchi Memorial Clinic PET Center, Kagoshima, Japan., Department of Radiology, Dokkyo Medical University, Shimotuga-gun, Japan., Department of Urology, Kanagawa Cancer Center, Yokohama, Japan., Department of Urology and Andrology, Kansai Medical University, Hirakata, Japan., Department of Urology, Osaka General Medical Center, Osaka, Japan., Department of Urology, Saiseikai Utsunomiya Hospital, Utsunomiya, Japan., Department of Urology, Anjo Kosei Hospital, Anjo, Japan., Department of Urology, Kobe City Medical Center General Hospital, Kobe, Japan., Division of Urology, Department of Surgery Related, Kobe University Graduate School of Medicine, Kobe, Japan., Clinical Development Department, Nihon Medi-Physics Co., Ltd, Koto-ku, Japan., Department of Urology, Kagawa University Faculty of Medicine, Kita-gun, Kagawa, Japan.