Long-term metabolic evolution of brain metastases with suspected radiation necrosis following stereotactic radiosurgery: longitudinal assessment by F-DOPA PET.

Background: The evolution of radiation necrosis (RN) varies depending on the combination of radionecrotic tissue and active tumor cells. In this study, we characterized the long-term metabolic evolution of RN by sequential PET/CT imaging with 3,4-dihydroxy-6-[18F]-fluoro-l-phenylalanine (F-DOPA) in patients with brain metastases following stereotactic radiosurgery (SRS).

Methods: Thirty consecutive patients with 34 suspected radionecrotic brain metastases following SRS repeated F-DOPA PET/CT every 6 months or yearly in addition to standard MRI monitoring.

Metabolic Evolution of Brain Metastasis After Stereotactic Radiosurgery: Mismatch Between F-DOPA and FDG PET.

The differentiation between radiation-induced changes and tumor recurrence is a major pitfall of magnetic resonance imaging, which can be overcome by the use of PET. Although amino-acid PET tracers showed several advantages over F-fluorodeoxyglucose in neurooncology, studies comparing these 2 types of radiopharmaceuticals in previously irradiated brain metastases are lacking. Here, we demonstrated a mismatch between 3,4-dihydroxy-6-[F]-fluoro-L-phenylalanine (F-DOPA) and FDG in the first report of a previously irradiated brain metastasis undergoing a longitudinal evaluation by sequential double tracer PET imaging.

F-DOPA uptake does not correlate with IDH mutation status and 1p/19q co-deletion in glioma.

Objective: The role of amino acid positron emission tomography (PET) in glioma grading and outcome prognostication has not yet been well established. This is particularly true in the context of the new WHO 2016 classification, which introduced a definition of glioma subtypes primarily based on molecular fingerprints. The aim of the present study was to correlate 3,4‑dihydroxy‑6‑[F]‑fluoro-L‑phenylalanine (F-DOPA) uptake parameters with IDH mutation, 1p/19q status, and survival outcomes in patients with glioma.

Hyperhomocysteinemia in acute iatrogenic hypothyroidism: the relevance of thyroid autoimmunity.

Purpose: Hyperhomocysteinemia is a known cardiovascular risk factor and a key player in the inflammatory activation of autoimmune diseases. Hashimoto's thyroiditis (HT) is the leading cause of hypothyroidism which, in itself, has been associated with a significant raise of homocysteine (Hcy) levels and increased cardiovascular risk. Our aim was to assess the impact of HT on Hcy levels in patients with acute hypothyroidism.