Clinical Nuclear Medicine最新文献

A 77-year-old woman with mild cognitive impairment was referred to 18F-florbetapir positron emission tomography (PET) to assess the indication of a disease-modifying drug against Alzheimer disease. PET images showed no uptake in the brain and only slight uptake in the sinus veins. In an automated injector, almost all the radioactivity was trapped in an air-vent filter, which is usually used for FDG injections and is made of mixed cellulose ester. After injection using other types of filters not made of mixed cellulose ester, 18F-florbetapir PET imaging was successful. The filter made of mixed cellulose ester should never be used for 18F-florbetapir injection.

Primary leptomeningeal melanomatosis is a rare and aggressive variant of primary central nervous system melanoma. Diagnosis is often challenging due to nonspecific radiologic features. We hereby report the 18F-FDG PET/CT and MRI findings in a case of primary leptomeningeal melanomatosis in a 47-year-old woman with a previously unidentified diastematomyelia. Spinal MRI showed diffuse abnormal signal. 18F-FDG PET/CT showed hypermetabolism most notably in the lumbar and caudal portion of the spinal cord, which was helpful to identify an appropriate site for biopsy.

Background: Glioblastoma (GBM) is the most common primary malignant tumor of the brain with high morbidity and mortality without an effective therapeutic option currently. This study aimed to evaluate the feasibility and safety of [ 177 Lu] Lu-prostate-specific membrane antigen (PSMA) therapy in patients with progressive/persistent refractory glioblastoma.

Patients and methods: This is a prospective single-arm pilot clinical trial with inclusion of 10 patients with progressive/persistent GBM on standard of care therapy. After evaluation of eligibility by [ 99m Tc] Tc-PSMA single-photon emission computed tomography (SPECT)/ low-dose CT, the patients received 2-6 cycles of 100-150 mCi with 4-5 weeks interval, and toxicity was assessed with regular hematologic and renal function tests as well as clinical history and examination. The response to therapy was also evaluated with magnetic resonance imaging (MRI).

Results: Among 23 patients who were referred for this trial, 10 patients finally were included and received 3-6 cycles [ 177 Lu] Lu-PSMA therapy. No hematologic or renal toxicity was noted. Clinical improvement or stability was seen in 9/10 patients. The comparison of MRI before and after therapy revealed 3 patients with partial response, 4 patients with stable disease and 3 patients with progressive disease. Six-month and 1-year survival rates were 100% and 80% after first dose of [ 177 Lu] Lu-PSMA therapy.

Conclusions: This study demonstrated that [ 177 Lu] Lu-PSMA therapy could be a safe and potentially effective salvage therapy in the progressive/persistent GBM and should be more evaluated with further dedicated study to assess more precise selection criteria and therapeutic protocol and timing.

Gallbladder neuroendocrine tumors (GB-NETs) are rare, accounting for <0.5% of all NETs, and little is known about somatostatin receptor expression (SSTR) and its response to SSTR-targeted treatment such as Lutetium-177 ( 177 Lu) DOTATATE. 68 Ga DOTATATE PET/CT is a valuable imaging modality for SSTR expression and 177 Lu DOTATATE treatment planning. We present a case of a 74-year-old man with recurrent WHO grade 3 GB-NET. 177 Lu DOTATATE failed to control hepatic metastases despite high DOTATATE uptake, which led to treatment discontinuation. This case highlights the fact that positive SSTR imaging in GB-NETs does not always lead to a favorable response to 177 Lu DOTATATE.

Tracheal inflammatory myofibroblastic tumors are exceedingly uncommon. This report presents the findings from an FDG PET/CT scan in a case involving an intratracheal inflammatory myofibroblastic tumor. Bronchoscopy revealed a neoplastic growth on the left lateral wall of the mid-trachea. The subsequent FDG PET/CT scan demonstrated intense radiotracer uptake within the lesion, with a maximum standardized uptake value (SUVmax) of 8.0. Post-surgical resection, immunohistochemical analysis corroborated the diagnosis of a tracheal inflammatory myofibroblastic tumor.

An increasing interest in radiopharmaceutical therapy (RPT), especially in reference to the theranostic framework incorporating both diagnostic and therapeutic components have been reported. Typically, this "theranostic approach" consists of a "matching pair" of radiopharmaceuticals, comprising a diagnostic partner labelled with positron or gamma-emitting radionuclides and a therapeutic partner labelled with beta or alpha-emitting radionuclides. Due to variability in the biodistribution, uptake, and retention, the therapeutic effectiveness of established and newer radiopharmaceutical therapies may show interpatient and intrapatient variability. As RPT requires the systemic administration of radiopharmaceuticals to patients, their normal organ biodistribution, as well as uptake in tumor tissues, can be mapped using molecular imaging (SPECT and PET) techniques. This allows for the quantification of the fraction of the administered radioactivity (MBq) that reaches the tumor, as well as the normal organs. The administered radioactivity can be modified based upon a patient's body habitus and laboratory parameters to achieve the optimal and desired tumor effect and normal tissue sparing, thereby permitting delivery of an individualized theranostics. This review discusses the RPT and dosimetry practices that are in clinical use, along with other cutting-edge radiopharmaceutical therapies that have shown promising therapeutic efficacies in advanced-stage human malignancies.

A 57-year-old woman with a history of right breast cancer surgery 22 years prior presented with CT findings of gastric and intestinal wall thickening, accompanied by mild-to-moderate FDG uptake on 18F-FDG PET/CT. Pathological results showed lobular breast cancer metastasis. The lesions showed significantly higher uptake on 18FAl-NOTA-FAPI PET/CT, and an additional sternal metastasis was identified.

Benign prostatic hyperplasia can show low-grade PSMA uptake, but rarely shows high-grade PSMA uptake. We describe 18 F-PSMA-1007 PET/CT and PET/MRI findings in a case of large benign prostatic hyperplasia with chronic inflammatory infiltrates and a high level of serum total prostate-specific antigen (32.6 ng/mL). The large benign prostatic hyperplasia of the transition zone showed heterogeneous signal intensity on the T2-weighted image and heterogeneous intense PSMA uptake with SUV max of 19. This case indicates that benign prostatic hyperplasia with chronic inflammation can show high-grade PSMA uptake mimicking or masking prostate cancer of the central gland.

Intracranial Rosai-Dorfman disease presents most commonly with dura-based, extraparenchymal masses mimicking meningioma. Rosai-Dorfman disease of the brain parenchyma is very rare. We describe FDG PET/CT findings in a case of primary multifocal intraparenchymal Rosai-Dorfman disease of the cerebrum and cerebellum. These tumors, located in the cortical, subcortical, or periventricular areas, showed inhomogeneous enhancement with or without surrounding edema on MRI and variable FDG activity (SUV max range, 4.5-18) on FDG PET/CT.

Pancreatic adenosquamous carcinoma (PASC) represents a rare, aggressive exocrine neoplasm. We describe a 33-year-old woman with an aggressive disease trajectory and limited survival. Baseline [18F]FDG PET/CT enabled accurate staging and treatment planning of stage IV malignancy. Following FOLFIRINOX chemotherapy, complete metabolic resolution was achieved on follow-up [18F]FDG PET/CT. Nevertheless, disease relapse ensued within 5 months. During restaging, [18F]FDG PET/CT failed to reveal any hypermetabolic lesions, whereas [68Ga]Ga-FAPI PET/CT successfully identified both local and metastatic recurrences. Notably, this case highlights the superiority of [68Ga]Ga-FAPI PET/CT for detecting recurrent PASC compared with [18F]FDG PET/CT.