Correlation between F18-FDG PET/CT Imaging and BRAF V600E Genetic Mutation for the Early Assessment of Treatment Response in Papillary Thyroid Cancers

In thyroid neoplastic pathology, the BRAF V600E mutation is shown to be involved in the oncogenesis of papillary thyroid cancer and its subtypes. The purpose of this study is to evaluate the correlation between the mutation of the BRAF V600E oncogene and the pathological standardized uptake values (SUV) at the F18-fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (PET/CT) evaluation, for a group of 20 patients with radically treated (total thyroidectomy and radioiodine therapy) papillary thyroid cancer, with subclinical persistent disease, at 6 months after the initial treatment. We analyzed the correlations between the values of SUV and the presence of the BRAF mutation as well with other prognostic factors such as stage, age, specific tumor markers (thyroglobulin and anti-thyroglobulin), extrathyroid extension, the presence of metastatic lymph nodes or distant metastasis. The value of SUV in the case of BRAF+ (positive) patients was higher than in the negative ones, but without statistical significance, thus, the values of the SUV cannot be a predictable factor for the presence of the genetic mutation. There was a statistically significant correlation in BRAF+ subgroup between the SUV values and the positive resection limit following surgery, showing a higher SUV value in the PET/CT evaluation. No correlation was observed between the aforementioned prognostic factors involved in papillary thyroid cancer and the BRAF V600E mutation

Evaluation of Malignancy Risk in 18F-FDG PET/CT Thyroid Incidentalomas

Thyroid incidentalomas detected by 18 fluoro-2-deoxy-d-glucose (FDG)-positron emission tomography/computed tomography (PET/CT) are a real challenge for nuclear medicine physicians and clinicians. This study aimed to evaluate the risk of malignancy for patients with focal thyroid incidentalomas (TIs) diagnosed through FDG PET/CT. Data from 6900 patients, with a known primary tumor, who had an FDG PET/CT investigation performed were analyzed for the presence of incidental thyroid uptake. The focal TIs were reported, and the patients were referred for further investigation to the endocrinology department. There were 126 patients (1.82%) who presented with focal thyroid uptake, and for 87 of them, investigations were completed with ultrasonography (US), and for 29 with a fine needle aspiration biopsy (FNAB) procedure. Malignancy was detected in 7.93% (10/126) of cases. An arbitrary cutoff value of four was established for the standard uptake value lean body mass (SUVlbm Max) to differentiate the malignant nodules from the benign ones, and this value was significantly associated with malignancy (p = 0.0168). TIs are not so frequent, but they have a potential malignancy risk, and a proper evaluation is required. Even though SUVlbm Max is a predictive factor for malignancy, the FNAB remains the main diagnostic method for the therapeutic management of these patients

Post-Treatment Thyroid Diseases in Children with Brain Tumors: A Single-Center Experience at “Prof. Dr. Ion Chiricuță” Institute of Oncology, Cluj-Napoca

Aim of study: The purpose of the study was to evaluate the association of thyroid dysfunction occurring in pediatric patients treated for brain tumors. Patients and methods: A total of 255 patients with brain tumors were treated between 2001 and 2018 at the “Prof. Dr. Ion Chiricuță” Institute of Oncology, Cluj-Napoca. Due to a minimum follow-up of 4 years, we studied 184 out of the 255 patients. The cohort included 69 girls (37.5%) and 109 boys (62.5%), with a median age of 8.4 years. The evaluated tumors included medulloblastomas (47 patients), astrocytomas (44 patients), ependymomas (22 patients), gliomas (20 patients), germ cell tumors (12 patients), primitive neuroectodermal tumors (4 patients), as well as other types of tumors (15 patients); in 20 of the cases, biopsy could not be performed. Results: There was a 60% overall survival rate; among the 120 surviving patients, 11 (9.1%) were diagnosed with iatrogenic thyroid disease. We observed an important number of iatrogenic thyroid disease cases in this group of patients, thus revealing the importance of long-term thyroid function evaluation in all children who finalized their treatment for brain tumors. Through this study, we aimed to provide an accurate image of the methodology of monitoring for thyroid dysfunction in childhood brain tumor survivors. Conclusion: Given the fact that the probability of developing thyroid dysfunction in the pediatric population treated for brain tumors is not rare, we recommend that childhood brain tumor survivors be monitored for iatrogenic thyroid disease, in order to provide early diagnosis and treatment