From the Guidelines
Fluciclovine (18F) is not indicated for use in patients with medullary thyroid cancer and should be avoided in this population. This radiopharmaceutical is primarily FDA-approved for PET imaging in men with suspected prostate cancer recurrence, as it targets amino acid transporters that are overexpressed in prostate cancer cells 1. Medullary thyroid cancer has different biological characteristics and imaging requirements, making Fluciclovine (18F) inappropriate for this cancer type. Instead, patients with medullary thyroid cancer typically undergo imaging with other radiopharmaceuticals such as 18F-DOPA PET/CT, 68Ga-DOTATATE PET/CT, or conventional imaging like ultrasound, CT, or MRI depending on the clinical scenario. Additionally, serum calcitonin and carcinoembryonic antigen (CEA) levels are important biomarkers for monitoring medullary thyroid cancer 1. The mismatch between the biological target of Fluciclovine and the characteristics of medullary thyroid cancer would likely result in suboptimal imaging results and potentially misleading clinical information.
Some key points to consider:
- Medullary thyroid cancer derives from the neuroendocrine parafollicular cells (C cells) of the thyroid gland 1
- The primary treatment guidelines for medullary thyroid cancer are outlined in the NCCN guidelines, which do not recommend the use of Fluciclovine (18F) for this cancer type 1
- Other radiopharmaceuticals, such as 18F-DOPA PET/CT and 68Ga-DOTATATE PET/CT, are more suitable for imaging medullary thyroid cancer due to their ability to target specific biological characteristics of this cancer type 1
Overall, the use of Fluciclovine (18F) in patients with medullary thyroid cancer is not recommended due to its limited efficacy and potential to provide misleading clinical information.
From the FDA Drug Label
CONTRAINDICATIONS None ( 4) The FDA drug label does not answer the question.
From the Research
Contraindications to Fluciclovine (18F) in Medullary Thyroid Cancer
There are no direct contraindications to Fluciclovine (18F) in patients with medullary thyroid cancer mentioned in the provided studies 2, 3, 4, 5, 6.
Type of Thyroid Cancer
The studies primarily focus on the diagnostic value of various PET tracers in medullary thyroid cancer (MTC) and other types of thyroid cancer.
- Medullary thyroid cancer is a rare type of thyroid cancer that originates from the parafollicular cells (C cells) of the thyroid gland 3, 4, 5.
- The studies discuss the use of different PET tracers such as 18F-FDG, 18F-DOPA, and 18F-Fluorocholine in the diagnosis and staging of MTC 3, 4, 5.
- The diagnostic accuracy of these tracers varies, with 18F-DOPA PET showing higher sensitivity and specificity for detecting MTC lesions compared to 18F-FDG PET and other imaging modalities 3.
Key Findings
- 18F-FDG PET has a sensitivity of 85.7% and specificity of 83.3% for detecting recurrent or metastatic MTC 4.
- 18F-DOPA PET is superior to 18F-FDG PET and other imaging modalities for detecting MTC lesions, especially in patients with high serum calcitonin levels 3.
- 18F-Fluorocholine PET/CT shows promise in the primary staging of MTC, with high sensitivity and positive predictive value for detecting MTC lesions 5.
- An increase in lesional SUV on 18F-FDG PET/CT scans is associated with subsequent tumor growth and may prompt earlier or more aggressive intervention 6.