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

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

BACKGROUND

According to the National Comprehensive Cancer Network Guidelines, 18F-fluciclovine PET/CT is considered appropriate after negative standard of care (SOC) imaging.

OBJECTIVE

To prospectively compare 18F-fluciclovine to SOC imaging, investigate whether it should be done when SOC imaging is (+), and evaluate its detection rate in patients receiving androgen deprivation therapy.

METHODS

We recruited 57 prostate cancer patients with biochemical recurrence with 18F-fluciclovine PET/CT and SOC imaging within 30 days. Prostate-specific antigen (PSA) level, Gleason score (GS), history of radical prostatectomy (RP), radiation therapy (RT) or hormone therapy (HT) were reviewed.

RESULTS

The 57 patients had a median PSA of 2.6 and average GS of 7.4; 27 (47.4%) had RP, 28 (49.1%) had RT, 1 (1.75%) had HT and 1 (1.75%) observation only. 18F-fluciclovine identified disease recurrence in 45/57 patients (78.9%), including oligometastasis in 18/45 (40%). SOC imaging identified recurrent disease in 12/57 patients (21.1%) while 18F-fluciclvoine identified additional sites of disease in 11/12 (91.7%). The (+) 18F-fluciclovine studies had a median PSA 2.6 ng/ml compared to 6.0 ng/ml in the (+) SOC studies.

CONCLUSION

18F-fluciclovine was superior to SOC imaging for lesion detection, identification of oligometastasis and identification of additional sites of disease.

PET/CT variants and pitfalls in prostate cancer: What you might see on PET and should never forget

2-deoxy-2-[¹⁸F]fluorodeoxyglucose (FDG) positron emission tomography (PET) gained an impressive role in the diagnostic management of many oncological diseases, even though its use in imaging prostate cancer (PC) is limited to selected cases, mostly advanced stage of PC and selection for prostate specific antigen membrane (PSMA) radioligand therapy (RLT). In the past years, several PET tracers have been developed for both staging and restaging PC. The three most employed PET molecules in daily practice are [¹¹C] or [¹⁸F]F-Choline, [¹⁸F]F-Fluciclovine (Anti-1- amino-3-[18F]Fluorocyclobutane-1-Carboxylic Acid, also known as (Anti-[¹⁸F]FACBC), [⁶⁸Ga]Ga-PSMA and recently FDA approved the first Fluorinated PSMA-based named [¹⁸F]F-DCFPyl. Each one has its own physiological and peculiarity which are worth exploring. Moreover, an increasing number of case reports and studies have reported tracers' variants, pitfalls, or even non-prostatic diseases (benign and malignant) incidentally detected. In prostate oncology, PET can be performed with several indications in different stages of disease, as highlighted in the EAU Guidelines on PC. A correct scan interpretation depends on the knowledge of both the physiological distribution of the tracers and the uptake of possible variants and pitfalls. The aim of this critical review is to provide a comprehensive knowledge of physiological distribution of these three tracers, as well as an updated overview of variants and pitfalls.

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

ABSTRACT

18F-Fluciclovine is an amino acid-based radiopharmaceutical used primarily for PET imaging of patients with biochemical recurrence of prostate cancer. We report a case of a 66-year-old man with recently diagnosed metastatic castrate-resistant prostate cancer and a left supraclavicular lymph node with incidental radiotracer uptake on 18F-fluciclovine PET/CT. Left neck core needle biopsy confirmed high-grade, poorly differentiated carcinoma with neuroendocrine features positive for synaptophysin and chromogranin, and negative for prostate markers.

Synchronous Malignancies Identified by 18F-fluciclovine Positron Emission Tomography for Prostate Cancer: Case Series and Mini-Review

Positron emission tomography using the fluorine-18 (¹⁸F) fluciclovine radiotracer has been approved for use in recurrent prostate cancer and is a useful tool for clinical decision making. However, ¹⁸F-fluciclovine is not specific for prostate cancer tumor cells, and false-positive results have been reported. In the present study, we have reported our experience with synchronous malignancies identified using ¹⁸F-fluciclovine and reviewed other reported cases, with a special emphasis on highlighting the clinical decisions that led to the correct diagnosis.