Clinical Nuclear Medicine最新文献

Metastases from meningioma are very rare and occur predominantly in WHO grade II and III tumors, with the lungs being the most common site. The increasing use of 68Ga-DOTA-peptides PET/CT has improved the detection of primary and secondary tumor sites. This imaging modality, evaluating the tumor expression of somatostatin receptors (SSTR), not only refines the diagnostic accuracy but also can guide a subsequent peptide receptor radionuclide therapy (PRRT). We report a case of meningioma brain tumor becoming refractory after initial neurosurgery and stereotactic radiotherapy. Meningioma has progressed to lung metastases displaying high expression of SSTR, and hence suitable for PRRT.

Background: Although a phase 3 trial did not demonstrate a survival benefit for gemcitabine, cisplatin, and nab-paclitaxel (Gem/Cis/Nab-P) in advanced biliary tract cancer (BTC), favorable outcomes were observed in specific patient subgroups, notably those with locally advanced disease or gallbladder carcinoma (GBC). This study aimed to assess the prognostic value of FDG PET/CT-derived parameters in advanced BTC patients treated with the Gem/Cis/Nab-P regimen, thereby identifying potential PET/CT imaging biomarkers that may aid in predicting survival benefit.

Patients and methods: We conducted a retrospective analysis of 125 advanced BTC patients who underwent pretreatment FDG PET/CT followed by Gem/Cis/Nab-P therapy. From the PET/CT images, maximum standardized uptake value, metabolic tumor volume, and total lesion glycolysis (TLG) of primary tumors were quantified. The influence of these parameters on prognostic outcomes was determined.

Results: Multivariate survival analysis identified TLG as an independent significant prognostic factor for both progression-free survival (PFS) and overall survival (OS) ( P <0.05). In subgroup analyses stratified by disease stage and TLG, patients with locally advanced disease and low TLG achieved the most favorable survival outcomes (median PFS, 18.4 months; median OS, not reached). Among tumor subtypes, TLG effectively differentiated PFS and OS in GBC patients, with the low TLG group exhibiting a median PFS of 11.7 months.

Conclusions: TLG on pretreatment FDG PET/CT served as an independent prognostic biomarker for PFS and OS in advanced BTC. Locally advanced disease and low TLG, as well as GBC with low TLG, might be predictive of enhanced survival benefit from Gem/Cis/Nab-P therapy.

We present a 73-year-old man with de novo metastatic prostate cancer who had received chemotherapy and androgen deprivation therapy (ADT). An increase in his serum prostate-specific antigen (PSA) level during ADT prompted a referral for restaging. A 99m Tc-HYNIC-PSMA-11 scintigraphy was conducted, which revealed uptake in the peritoneal cavity that was initially interpreted as normal intestinal excretion on the whole body scan but was later clarified through SPECT/CT imaging. This case underscores the potential of functional imaging, even conventional methods, to surpass anatomical imaging techniques such as CT scans, which have limited soft tissue resolution, in assessing peritoneal involvement.

We presented the imaging findings of 18 F-FDG and 68 Ga-HER2 affibody PET/CT in a 52-year-old woman with HER2-positive accessory breast cancer in the right axilla. 18 F-FDG and HER2 PET/CT showed avid uptake of multiple axillary lesions. HER2 PET/CT identified extensive bone metastases with intense uptake, while the ⁹⁹ᵐTc-MDP whole bone scan was negative, and only a few bone lesions with mild tracer uptake were detected by 18 F-FDG PET/CT. Following 6 cycles of the TCbHP regimen, the axillary lesions markedly reduced. This case demonstrates that HER2 PET/CT enables more sensitive detection of HER2-positive lesions, thereby allowing for precise staging and guiding HER2-targeted therapy.

A comparative evaluation using both 18 F-FDG-PET/CT and 68 Ga-FAPI-04 PET/CT in primary staging of a treatment-naïve anterior mediastinal seminoma is illustrated in this report. A 30-year-old man presented with elevated human chorionic gonadotropin levels and biopsy-proven seminoma of the anterior mediastinum. The investigation was performed for primary staging, considering that both tracers may show uptake in the germ cell tumors in the anterior mediastinum, and the potential role of 68 Ga-FAPI-04 PET/CT in treatment-naïve mediastinal seminoma would be examined. The germ cell tumors comprise 1%-4% of mediastinal tumors, and seminomas are less frequent than non-seminomatous tumors.

Pheochromocytomas are rare catecholamine-secreting tumors arising from the adrenal medulla, often presenting with episodic hypertension, palpitations, and diaphoresis. Meanwhile, undifferentiated carcinoma of the uterine corpus is an aggressive and poorly differentiated endometrial malignancy with a high propensity for metastasis and poor prognosis. The incidental detection of such an aggressive malignancy in a patient undergoing evaluation for pheochromocytoma is exceedingly rare and poses significant diagnostic and therapeutic challenges. Here, we present a case of a 63-year-old woman who was being evaluated for right pheochromocytoma and underwent 131 I-MIBG scan for the same, which led to incidental detection of synchronous uterine carcinoma.

Von Hippel-Lindau (VHL) disease is a rare, autosomal dominant, multisystem cancer syndrome. A variety of benign and malignant tumors can develop in VHL, including cranial and spinal hemangioblastomas, retinoblastoma, endolymphatic sac tumor, pheochromocytoma, renal cell carcinoma, pancreatic neuroendocrine tumors, and renal, pancreatic, and genital cysts. Here we present a 57-year-old woman who was diagnosed with VHL and, in the same 68 Ga-DOTATATE PET/CT, exhibits all these components of the syndrome: pheochromocytoma, pancreatic neuroendocrine tumor, pancreatic cysts, renal cysts, liver hemangioma, and hemangioblastoma in the medulla oblongata.

PSMA-targeted radioligand therapies with 177 Lu-PSMA-617 have shown promising response rates with favorable toxicity in patients with metastasized castration-resistant prostate cancer. We report a case of a 72-year-old man with metastatic castration-resistant prostate cancer having comorbidities of DM, HTN, and end-stage renal disease (ESRD) on regular hemodialysis. The patient received 2 doses of 7.4GBq of 177 Lu-PSMA-617, 6 weeks apart. There was complete resolution of prior 68 Ga-PSMA avid lesions, a significant decrease in serum PSA level, and symptomatic response after therapy. We suggest that patients with ESRD on dialysis can be safely treated with 177 Lu-PSMA radionuclide therapy.

Follicular dendritic cell sarcoma (FDCS) of the duodenum is extremely rare. We describe the contrast-enhanced CT and FDG PET/CT findings in a case of duodenal FDCS. Contrast-enhanced CT revealed a large, irregular mass originating from the horizontal portion of the duodenum. The mass demonstrated heterogeneous enhancement, with internal areas of low-attenuation necrosis and coarse calcifications. The mass showed significantly increased FDG uptake. The patient underwent surgical resection, and histopathologic examination revealed a spindle cell tumor positive for CD21 and CD35, confirming the diagnosis of FDCS.

A 58-year-old woman presented with disabling bone pain and muscle weakness. Laboratory tests were unremarkable, except for decreased serum phosphate and elevated urine phosphate levels. A 99m Tc-MDP scan revealed multiple sites of bone fractures. Both 18 F-FDG PET/CT and 99m Tc-FAPI-46 scans identified a lesion in the left heel, which was later resected and diagnosed as phosphaturic mesenchymal tumor on pathologic evaluation. This case represents a pioneering experience in utilizing FAPI for detecting the origin of tumor-induced osteomalacia. It underscores the potential utility of various radiopharmaceuticals in the diagnostic workup of these patients.