Molecular Imaging and Radionuclide Therapy最新文献

The majority of metastatic pleural lesions are caused by malignancies such as bronchogenic carcinoma (40%), breast cancer (20%), lymphoma (10%), and ovarian or gastric carcinomas (5%). However, pleural metastases from thymoma are extremely rare. In this report, we present the ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) imaging findings of a patient with thymoma and extensive pleural metastases. Although biopsy remains the gold standard for diagnosis, it is important to consider high grade thymoma in the differential diagnosis, as extensive pleural involvement observed on ¹⁸F-FDG PET/CT imaging can mimic both primary and metastatic pleural malignancies. Recognizing this possibility can assist in more accurate interpretation of imaging findings.

Objectives: This study aims to evaluate the effectiveness and role of telomere length measurements in leukocytes, plasma free cell DNA (cfDNA), and biopsy cells, along with technetium-99m (Tc-99m) methoxyisobutylisonitrile (MIBI) scintigraphy, as non-invasive methods for diagnosing malignant thyroid lesions.

Methods: Data from 128 patients, who underwent ultrasound, Tc-99m MIBI scintigraphy, and fine-needle biopsy with a preliminary diagnosis of malignant thyroid nodules, were analyzed. In 98 patients, telomere lengths in leukocytes (from blood), cfDNA (from plasma), and biopsy cells were measured using the quantitative polymerase chain reaction method, and the relative telomere/single copy gene (T/S) ratio was calculated. Based on cytological examination results, patients were categorized into three groups: malignant, benign, and suspicious. Group differences were analyzed using the Kruskal-Wallis and Chi-square tests, and correlations between variables were examined with Spearman correlation analysis.

Results: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of Tc-99m MIBI scintigraphy for diagnosing malignant thyroid nodules were 64.70%, 79.16%, 29.72%, 83.51%, and 67.96%, respectively. While these results align with the literature, the positive predictive value was notably lower. No significant differences were observed in telomere lengths (T/S ratios) in leukocytes, plasma, or tissue between the groups.

Conclusion: Tc-99m MIBI scintigraphy demonstrates reasonable diagnostic accuracy for identifying malignancy in thyroid nodules. Contrary to limited reports, telomere length measurements may not be a reliable method for predicting thyroid malignancy. Larger studies are needed to further explore these findings.

Disseminated candidiasis presents a significant diagnostic and therapeutic challenge in immunocompromised patients, particularly those with hematological malignancies like leukemia. ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) is a crucial imaging modality in oncology and infection, outperforming conventional imaging in diagnosing and managing fungal infections, especially in cases of fever of unknown origin. We present a compelling case of a young leukemia patient with persistent fever, demonstrating FDG-avid lesions in various organs, including the liver, spleen, and left kidney, indicative of disseminated candidiasis.This highlights the critical role of ¹⁸F-FDG-PET/CT in situations where invasive procedures like liver biopsy are challenging or contraindicated. Such instances underscore the paramount importance of utilizing advanced imaging techniques for accurate diagnosis and treatment, especially in the complex clinical setting of immunocompromised individuals, with hematological malignancies. This case emphasizes the significant contribution of ¹⁸F-FDG-PET/CT as a non-invasive diagnostic tool, enhancing patient care and enabling more effective management strategies amidst challenging medical circumstances.

Pancreatic exocrine carcinoma (PEC) is a lethal malignancy with high mortality rates because of its aggressive nature and frequent late-stage diagnosis. When histopathological diagnosis becomes unfeasible because of patient deterioration, clinicians must rely on clinical, biochemical, and radiological findings. This case report describes a 78-year-old woman with aggressive PEC visualized through ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography. The imaging revealed an intensely hypermetabolic head mass, hepatic superscan, and hypermetabolic abdominal lymphadenopathy. Despite strong clinical indicators suggesting stage IV PEC, rapid disease progression and patient demise precluded histopathological confirmation, emphasizing the poor prognosis associated with hepatic superscan in this context.

Objectives: To investigate the effects of glut polymorphisms on ¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) uptake rates.

Methods: The ¹⁸F-FDG positron emission tomography/computed tomography images and mass lesion metabolism standard uptake value maximum (SUV_max) results of the patients were evaluated. Glucose transporter protein-1 (GLUT-1)-XbaI G>T (rs2754218) and HaeIII T>C (rs1385129) polymorphisms and their effects on ¹⁸F-FDG uptake rates were investigated using DNA obtained from peripheral blood.

Results: When the Xbal G>T genotype distribution of the patients was examined, the Xbal G/G genotype was found to be 87%, the Xbal G/T genotype 12%. The XbaI T/T phenotype was detected in only one patient (1%). In the HaeIII T>C genotype distribution, the HaeIII C/C genotype was found as 54%, the HaeIII T/C genotype as 31%, and the HaeIII T/T genotype as 15%. When the Xbal and HaeIII genotypes were examined together, the number of polymorphic genotypes was significantly higher in the lung and bronchial tumor groups compared to other cancer types.

Conclusion: The presence of polymorphism in at least one of the two gene regions, in the lung-bronchial tumor group and the high SUV_max value in this patient group, may indicate a change in the involvement rates.

Gallium-68 (⁶⁸Ga)-prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) is a relatively new imaging modality that has already proved its role in the initial staging of prostate cancer and in biochemical recurrence following definitive primary therapy. Furthermore, emerging data several ongoing studies demonstrate its potential role in the primary diagnosis of this malignancy. We present a 67-year-old male patient with increasing clinical suspicion of prostate cancer despite a previous negative prostate gland biopsy. He was referred to our nuclear medicine department for a ⁶⁸Ga-PSMA PET/CT with the aim of improving tumor localization and assisting in the guidance of repeat prostate biopsy. One month before presentation of elevated prostate-specific antigen levels, he underwent multiparametric magnetic resonance imaging (mpMRI), which revealed a prostate imaging reporting and data system 4 lesion in the right lobe of the prostate gland. The MRI lesion completely matched a PRIMARY score 5 lesion registered by PET/CT. Furthermore, we detected another suspicious finding in the left lobe (PRIMARY score 4). The patient underwent PSMA PET/CT-guided MRI/ultrasonography fusion transperineal biopsy of both lesions. The latter were histologically confirmed as prostate carcinoma with a Gleason score of 3+4 =7.

We present the ⁶⁸Ga-prostate-specific membrane antigen (PSMA) and ⁶⁸Ga-fibroblast activation protein inhibitor (FAPI)-04 positron emission tomography/computed tomography (PET/CT) findings comparatively of a 76-year-old man with a history of progressive dyspnea and evidence of interstitial lung disease (ILD) abnormalities on high-resolution CT. Moderate PSMA uptake was observed in areas with ILD abnormalities on ⁶⁸Ga-PSMA PET/CT. ⁶⁸Ga-FAPI-04 PET/CT showed relatively higher FAPI-04 uptake in these regions. These findings offer the potential to assess disease activity at the cellular and molecular levels. This approach may provide valuable insight into the pathophysiology of ILD beyond the structural changes captured by traditional imaging methods.

A rare tumor, intestinal-type adenocarcinoma (ITAC), accounts for 8-25% of all sinonasal malignancies. The tumor's histological resemblance to gastrointestinal tract adenocarcinoma is implied by its name. ITAC develops in the ethmoid sinus and upper nasal cavity. Herein, we present sinonasal ITAC with increased prostate-specific membrane antigen expression and fluorodeoxyglucose uptake.

Objectives: ¹⁸Fluorine-fluorodeoxyglucose (¹⁸F-FDG) uptake in the spinal cord is not unusual and may mimic metastatic disease. The physiological characterization and variability of spinal cord ¹⁸F-FDG metabolism provide valuable information, especially in patients with suspected malignancies. We aimed to investigate the physiological ¹⁸F-FDG uptake pattern within the spinal cord and its associations in a normal population.

Methods: We retrospectively analyzed ¹⁸F-FDG positron emission tomography/computed tomography images of 140 adult patients who were confirmed to be disease-free over a one-year follow-up period. The maximal and mean standard uptake values (SUV_max, SUV_mean) were measured at each mid-vertebral level from C1 to L5, and normalized to liver and blood pool uptake. Correlations between ¹⁸F-FDG uptake and patient demographics, clinical parameters, and environmental temperature were evaluated.

Results: ¹⁸F-FDG uptake demonstrated a decreasing trend from the cervical to lumbar vertebrae, with a notable increase at the lower thoracic levels (T11-T12). There was a significant negative correlation between ¹⁸F-FDG uptake and age (p<0.001), fasting glucose level (p=0.016), and diabetic status (p=0.003). No significant association was found between spinal cord ¹⁸F-FDG uptake and gender, weight, height, body mass index, ¹⁸F-FDG dose, or environmental temperature.

Conclusion: Normal distribution of ¹⁸F-FDG in the spinal cord of disease-free individuals decreases from cervical to lumbar levels, although it notably increases at the lower thoracic and mid-lower cervical levels. Uptake significantly decreases with age, with a higher fasting blood glucose level, and in diabetic patients.

⁶⁸Ga--prostate-specific membrane antigen (PSMA)-11 positron emission tomography/computed tomography (PET/CT) is currently routinely used for the evaluation of prostate cancer. However, due to its whole-body imaging capability, it can incidentally identify pathologies beyond prostate cancer. Herein, we describe a case of a 67-year-old man who was recently diagnosed with prostate carcinoma (PCa). The patient had a high PSMA-avid thyroid carcinoma detected incidentally during the initial staging of PCa with ⁶⁸Ga-PSMA-11 PET-CT.