Indian Journal of Nuclear Medicine最新文献

A 60-year-old man who never smoked presented with a 2-month history of dull, poorly localized right-sided chest pain and a dry cough. He also reported a loss of appetite and unintentional weight loss. On clinical examination, he was hemodynamically stable, with clear breath sounds bilaterally. His hemogram and biochemical parameters were within normal limits, and electrocardiography showed a normal sinus rhythm. A posteroanterior chest radiograph revealed a suspicious mass lesion in the right upper zone. Contrast-enhanced computed tomography (CT) of the chest demonstrated a 70 mm × 40 mm × 61 mm spiculated, heterogeneously enhancing soft-tissue lesion in the apical segment of the right upper lobe. Whole-body ¹⁸F-fluorodeoxyglucose positron/emission tomography (FDG PET) showed avid uptake in the lesion (maximum standardized uptake value, 8.4), suggesting high metabolic activity consistent with malignancy. Radial endobronchial ultrasound (EBUS)-guided transbronchial lung biopsy was performed. Fiberoptic bronchoscopy showed no visible endobronchial growth. Biopsy specimens obtained under radial EBUS guidance yielded inconclusive histopathologic findings. A follow-up CT-guided percutaneous biopsy of the mass demonstrated necrotic material only, without viable tumor cells. The imaging features and metabolic activity were strongly suggestive of malignancy, yet repeated biopsy attempts failed to yield diagnostic tissue. The case underscores the diagnostic difficulty in sampling centrally necrotic tumors and the need for integrating imaging with clinical and histologic correlation.

Metastasis from differentiated thyroid cancer frequently occurs in regional lymph nodes, followed by the lungs and bones. However, mandibular metastases related to thyroid carcinoma are exceedingly rare and may represent the sole manifestation of an undiagnosed underlying malignancy. This study aims to analyze the presentation, management, and survival outcomes in a case series of differentiated thyroid carcinoma patients having mandibular metastasis.

We report a unique case of a patient with histopathologically proven diffuse large B-cell lymphoma (DLBCL) who underwent both ¹⁸F-fluorodeoxyglucose and ⁶⁸Ga-Pentixafor positron emission tomography/computed tomography scans. The imaging findings showed an identical pattern of radiotracer uptake in disease-involved sites, including lymph nodes and extranodal sites. Despite the tracers having unrelated mechanisms, this concordance in imaging underscores the potential for complementary roles in disease staging, response evaluation, and theranostic applications in DLBCL cases exhibiting CXCR4 expression.

Metastatic melanoma is the most life-threatening skin cancer due to its significant tendency to metastasize and its substantial resistance to therapeutic interventions. Melanomas spread aggressively, particularly to lymph nodes, the brain, and lungs, and can also involve the adrenal gland, liver, bones, and small intestine. Metastasis to the endometrium is exceedingly rare, with only a handful of documented cases. Fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is an excellent modality for detecting metastases. A meta-analysis showed that PET/CT has superior diagnostic performance, with 88% sensitivity and 94% specificity, compared to other contemporary imaging techniques. We present a 55-year-old postmenopausal female, diagnosed with primary cutaneous melanoma of the right foot and initially treated with temozolomide. After 2 years, she presented with vaginal bleeding. Restaging with ¹⁸F FDG PET/CT revealed multiple nodal metastases with chest and abdominal wall deposits and confirmed uterine metastases.

Purpose of the study: This study compared striatal dopamine metabolism and cerebral glucose metabolism in Parkinson's disease patients with and without freezing of gait (FOG) using Fluorodeoxyglucose positron emission tomography (FDG-PET) and F-DOPA PET. We also compared the two groups' cognitive, affective, and autonomic functions.

Methods: Patients were divided into two groups: those with and without FOG. All patients underwent neuropsychological evaluation. Subsequently, both groups underwent FDG-PET and FDOPA-PET. The FDOPA PET/computed tomography images evaluated dopaminergic expression in the basal ganglia. Cortex-ID-based processing of FDG images was visually analyzed for any abnormal hypermetabolism or hypometabolism in the various regions of the brain.

Results: A total of 30 patients were recruited, 15 in each group. The mean age of participants was 59.33 ± 9.12 years in the freezing of the gait-negative group and 61.13 ± 9.38 years in the freezing of the gait-positive group. FDOPA PET scan analysis revealed symmetrical loss of basal ganglia uptake in the freezers compared to the nonfreezers, which had more asymmetrically reduced uptake (P = 0.025). In FDG PET, a general trend of greater metabolic reduction in the basal ganglia was observed in freezers. Our study showed bilateral involvement of frontoparietal cortices in both freezers and nonfreezers, with more widespread areas of hypometabolism reported in the freezer group.

Conclusion: Freezers exhibited a more symmetrical loss of dopaminergic uptake on FDOPA PET, whereas nonfreezers showed greater asymmetry. In addition, FDG PET revealed a trend toward greater basal ganglia hypometabolism in freezers, suggesting a more profound striatal dysfunction in patients with freezing of gait.

Hepatoid adenocarcinoma of the lung (HAL) is an exceptionally rare and highly aggressive form of extrahepatic adenocarcinoma. Characterized by alpha-fetoprotein production and exhibiting morphological features akin to hepatocellular carcinoma, it poses significant diagnostic and therapeutic challenges. We present the case of a 39-year-old male with a history of smoking, who sought medical attention for right-sided chest pain, cough, and difficulty breathing. Imaging studies, including a chest X-ray and ¹⁸F-FDG PET/CT scan, revealed a pulmonary mass with intense FDG uptake. Further pathological analysis confirmed the diagnosis of HAL, highlighting the importance of early recognition and accurate diagnosis of this rare malignancy.

The present report describes a patient of metastatic castration-resistant prostate cancer (mCRPC) with dural-based brain metastasis, discordant and variable [⁶⁸Ga] Ga-prostate specific membrane antigen (PSMA)-11 and [¹⁸F] fluorodeoxyglucose ([¹⁸F] FDG) uptake in metastases on dual-tracer positron emission tomography computed tomography (PET/CT), illustrating three important teaching points: (a) Dual-tracer PET/CT demonstrating discordant tumor biology pattern between soft tissue and skeletal metastatic lesions in mCRPC even within the same individual, thereby provides a more comprehensive overview of whole-body tumor status, with implications for personalized patient profiling and treatment selection (b) valuable role of [¹⁸F] FDG-PET/CT in identifying PSMA-negative lesions (neuroendocrine transformation) in mCRPC patients, including the possibility of detecting second primary cancer, (c) high metabolic tumor volume on [¹⁸F] FDG-PET/CT associated with aggressive biology and adverse prognosis.

Although gastric cancer is a prevalent malignant tumor worldwide, gastric cancer with bone marrow metastasis is rare and associated with extremely poor prognosis. The clinical manifestations of bone marrow metastasis are diverse and nonspecific, with diagnosis primarily confirmed through bone marrow biopsy. ¹⁸F fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F FDG PET/CT) serves as a sensitive modality for detecting bone marrow metastasis. We present a case of a female patient with gastric adenocarcinoma complicated by bone marrow metastasis, who presented with systemic pain and fatigue. ¹⁸F FDG PET/CT revealed metabolically active lesions in the vertebral column and multiple skeletal sites, while conventional CT showed no apparent signs of bone destruction.