The Complementary Roles of 18F-Fluorocholine and 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in an Evaluation of A Patient With Parathyroid Carcinoma: A Case Report - Molecular Imaging and Radionuclide Therapy

Prostate cancer (PC) typically leads to osteoblastic metastases, primarily affecting the axial skeleton and subsequently the femur and humerus. We present a case in which the patient underwent bone scintigraphy (BS) following the diagnosis of PC-initially before the application of therapy due to suspicion of bone metastases and then a follow-up BS after therapy to evaluate treatment efficacy. A 69-year-old male patient underwent initial BS in October 2017. The scintigraphy results revealed multiple areas of asymmetrically increased radiopharmaceutical accumulation in the bones of the head, right clavicle, sternum, several ribs, the thoracic spine, all bones of the pelvis bilaterally, and the right femur. The BS conclusion indicated that the described lesions in the skeletal system were consistent with metastases originating from the previously diagnosed PC. In October 2021, the patient underwent a followup BS, after the applied therapy. Compared to the previous scintigraphic findings from 2017, the pathological process had shown complete regression within the skeletal system. No signs of bone metastases were detected. The presented case underscores the pivotal role of BS in detecting skeletal metastases and evaluating patients with confirmed metastases. The initial BS, in conjunction with other diagnostic methods, facilitated the selection of appropriate therapeutic modalities. Conversely, follow-up BS enabled the evaluation of treatment efficacy, and with a low prostate-specific antigen (PSA) level in the blood, the decision was made to discontinue therapy.

The aim of this novel study was to explore the possibility of the development of a machine learning (ML) model that can predict early response to radioactive iodine (RAI) therapy in patients with hyperthyroidism on the basis of demographic, clinical, laboratory, and imaging features. A total of 914 patients who received RAI for the treatment of hyperthyroidism between January 2000 and December 2023 were included in the study. The early positive response, defined as an accomplishment of hypothyroidism (thyroid-stimulating hormone (TSH) > 4 mIU/L) in the 6-month period following RAI therapy, was accomplished in 336 patients (36.76%) (hypothyroidism group), whereas hypothyroidism was not accomplished in 578 patients (63.24%) (control group). The training data consisted of 90% of the sample (822 patients), whereas the test set contained 92 patients. Multiple ML models, including k-nearest neighbors, random forest, various gradient boosting algorithms, and neural networks, were trained via AutoGluon. The neural network model performed the best, with a balanced accuracy of 68.81%, sensitivity of 61.76%, specificity of 75.86%, PPV of 60.0%, NPV of 77.19%, and F1 score of 60.87%, with the area under the curve (AUC) of 0.706 (95% confidence interval [CI]: 0.593-0.809; receiver operating characteristic [ROC] curve analysis). In the development of the top-performing model, baseline TSH, age, 24-h radioactive iodine uptake, dose, and duration of previous treatment with antithyroid drugs (ATDs) were the most important features. We developed models for the prediction of the response to RAI in patients with hyperthyroidism. However, these models require further development before they can be applied in clinical practice. By introducing more variables and increasing the sample size, the model performance can increase further.

Loeffler's endocarditis (LE) is a rare form of inflammatory cardiomyopathy. The condition arises from diffuse eosinophilic infiltration of the endomyocardium, followed by eosinophil degranulation and progressive tissue fibrosis. The aim of this case report is to present a rare form of restrictive cardiomyopathy, LE, in a young female patient, and to highlight the importance of fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) as a valuable diagnostic tool for accurate diagnosis, assessment of cardiac involvement, and determination of disease extent. We present the case of a female patient who underwent FDG PET/CT imaging due to suspected LE, following the detection of eosinophilia and a series of prior diagnostic procedures. FDG PET/CT contributed to the timely diagnosis and precise localization of inflammatory lesions in the cardiac walls. Based on the presented case, we conclude that FDG PET/CT imaging can serve as a helpful tool in the diagnosis and evaluation of LE due to its unique capability to visualize metabolic activity in tissues — a feature often beyond the reach of conventional diagnostic methods. This modality enables accurate identification of inflammatory lesions in the endocardium and myocardium, which are characteristic of LE.