Incidental Accumulation of Fluciclovine in Neuroendocrine Tumour in a Patient with Oncological Duplicity

Abstract

18F-fluciclovine is a PET radiopharmaceutical used for the detection of recurrent prostate cancer in adult men after primary curative treatment with suspicion of recurrence based on elevated prostate-specific antigen level. Several incidental uptakes of 18F-fluciclovine in other tumour types have been described in the literature so far -in breast cancer, hepatocellular carcinoma, and malignant melanoma. Our case report presents a patient with oncological duplicity (prostate gland carcinoma and newly diagnosed neuroendocrine tumour) and with accumulation of fluciclovine in pathologically proved neuroendocrine tumour, later imagined also by octreotide SPECT/CT. To our knowledge, this is the first case of fluciclovine accumulated in a neuroendocrine tumour described in the literature.In conclusion, incidental FCV uptake in cancer types other than prostate cancer has already been described, with our case report adding to this list. FCV PET is a tool to detect recurrent prostate cancer with rising PSA levels. In our case, the patient had low PSA levels and FCV uptake in metastases which were later proven to be NET. AcknowledgementWe would like to thank Dr. Pavel Veselý, PhD, clinical oncologist, for his help with the clinical data of the patient. Statement of EthicsWritten informed consent was obtained from the patient for the publication of this case report and accompanying images.

Poorly Differentiated Neuroendocrine Tumor With 18F-Fluciclovine Uptake in a Patient With Metastatic Castrate-Resistant Prostate Cancer

“…Neuroendocrine differentiation has been reported in patients with PCa on ADT, with associated poor prognosis 11–14 . Our findings are similar to a recently published study that reported incidental significant uptake of 18 F-fluciclovine in grade 1 NET of the lungs in a patient with primary PCa and low PSA levels postradiotherapy 15 . Bosserman et al also reported mild 18 F-fluciclovine uptake in well-differentiated rectal NET in a patient with rising PSA level postradical prostatectomy 16 .…”

“…[11][12][13][14] Our findings are similar to a recently published study that reported incidental significant uptake of 18 F-fluciclovine in grade 1 NET of the lungs in a patient with primary PCa and low PSA levels postradiotherapy. 15 Bosserman et al also reported mild 18 F-fluciclovine uptake in well-differentiated rectal NET in a patient with rising PSA level postradical prostatectomy. 16 18 F-Fluciclovine is a PET radiotracer primarily used in the evaluation of recurrent PCa.…”

Evaluating appropriateness of 18F-fluciclovine PET/CT relative to standard of care imaging guidelines and the impact of ADT on positivity: a prospective study in 62 Veterans Administration patients at a single institution

“…ASCT2 was less expressed in mCRPC. To date there are case reports of 18F-fluciclovine PET positivity in neuroendocrine tumors, both dedifferentiated prostate cancer and secondary malignancies [35][36][37]. Small cell/neuroendocrine prostate cancer, however, can lose 18F-fluciclovine positivity likely due to becoming more poorly differentiated [38].…”