ABSTRACT
BACKGROUND: Uveal melanoma metastasizes to the liver. We aimed to explore the metabolic activity of liver metastases (LM) as a biomarker for survival. METHODS: We analyzed newly diagnosed patients with metastatic UM (MUM) with LM detected by liver-directed imaging and had undergone a PET/CT at diagnosis. FINDINGS: 51 patients were identified between 2004 and 2019. Median age was 62 years, 41% male and 22% ECOG ≥1. LDH, ALP, and GGT were elevated in 49%, 37%, and 57% of patients. Median LM SUVmax was 8.5 (3-42.2). Same size lesions presented a wide range of metabolic activity. Median OS was 17.3 m (95% CI:10.6-23.9). Patients with SUVmax ≥8.5 had an OS of 9.4 m (95% CI:6.4-12.3), whereas patients with SUVmax <8.5 had an OS of 38.4 m (95% CI:21.4-55.5; p < 0.0001, HR = 2.9). We observed similar results when studying M1a disease separately. Multivariate analysis showed SUVmax as an independent prognostic factor for the whole population and those with M1a disease. INTERPRETATION: Increased metabolic activity of LM seems to be an independent predictor of survival. MUM is a heterogeneous disease and metabolic activity probably reflects a different intrinsic behavior.
Subject(s)
Liver Neoplasms , Melanoma , Uveal Neoplasms , Humans , Male , Middle Aged , Female , Positron Emission Tomography Computed Tomography , Melanoma/pathology , Uveal Neoplasms/pathology , Prognosis , Fluorodeoxyglucose F18 , Retrospective StudiesABSTRACT
OBJECTIVE: Medullary thyroid carcinoma (MTC) is a rare malignancy. Location of residual, recurrent, or metastatic disease is crucial to treatment management and outcome. We aimed to evaluate the use of F-FDG PET/CT in localizing MTC foci in patients with biochemical relapse. METHODS: This is a retrospective cohort study. Review of 51 FDG PET/CT studies of 45 patients referred to restage MTC due to increased calcitonin (Ctn) and carcinoembryonic antigen (CEA) values at follow-up. FDG PET/CT diagnostic accuracy was determined through a patient-based analysis, using histology as criterion standard when available, or other imaging studies and clinical follow-up otherwise (mean, 4 years). RESULTS: There were 25 positive scans. Sensitivity, specificity, positive and negative predictive values, diagnostic accuracy, and positive likelihood ratio were 66.7%, 83.3%, 88.0%, 57.7%, 72.5%, and 4.0, respectively. Using a Ctn cutoff of 1000 pg/mL, sensitivity increased to 76.9%. There were significant differences of Ctn and CEA values between positive and negative FDG PET/CT (P < 0.05). Regarding true-positive studies, average SUVmax comparing locoregional and metastatic disease was at the limit of significance (P = 0.046). CONCLUSIONS: PET/CT can be useful to restage patients with biochemical relapse of MTC, with a better performance in higher Ctn levels. Its high positive predictive value (88%) may impact in the therapeutic management, although its low negative predictive value (57.7%) makes strict follow-up mandatory in examinations without pathologic findings.
Subject(s)
Carcinoma, Neuroendocrine/diagnostic imaging , Carcinoma, Neuroendocrine/pathology , Fluorodeoxyglucose F18 , Positron Emission Tomography Computed Tomography , Thyroid Neoplasms/diagnostic imaging , Thyroid Neoplasms/pathology , Adult , Aged , Aged, 80 and over , Calcitonin/metabolism , Carcinoembryonic Antigen/metabolism , Carcinoma, Neuroendocrine/metabolism , Female , Humans , Male , Middle Aged , Neoplasm Metastasis , Neoplasm, Residual , Recurrence , Retrospective Studies , Sensitivity and Specificity , Thyroid Neoplasms/metabolism , Young AdultABSTRACT
A 78-year-old female patient with a 5-year history of bradykinesia and tremor at rest of both upper limbs was referred to our Nuclear Medicine Department because of a rapid functional decline over 3 months with cognitive impairment, generalized myoclonus, and dependence for most basic daily activities. Brain SPECT with 148MBq (4 mCi) of I-123 FP-CIT and 740MBq (20 mCi) of Tc-99m ethylcysteinate dimer (thereafter Tc-99m ECD) was performed.
