Clinical Nuclear Medicine最新文献

Purposes: This study aims to investigate the diagnostic performance of combining 68 Ga-pentixafor PET with MRI to differentiate primary central nervous system lymphoma (PCNSL) from glioblastoma (GBM), particularly focusing on atypical lymphoma identification.

Patients and methods: Seventy-one PCNSL and 53 GBM patients who underwent both 68 Ga-pentixafor PET/CT and MRI were retrospectively included. We evaluated the quantitative imaging parameters and MRI features of positive lesions, identifying atypical PCNSL by hemorrhage, necrosis, or heterogeneous enhancement. Logistic regression identified key variables, and the ROC-AUC evaluated their diagnostic value. Immunohistochemistry for CXCR4 was performed.

Results: PCNSLs, including 23 atypical cases, showed higher SUV max and TBR, and lower MTV, ADC min , and relative ADC min (rADC min ) than GBMs (all P 's < 0.05). The CXCR4 staining in PCNSL was also more pronounced in GBM ( P = 0.048). Multivariate logistic regression indicated that a combination of TBR, MTV, and ADC min (quantitative model 1) had a superior AUC of 0.913 in distinguishing PCNSL from GBM, outperforming single parameters (all P 's < 0.05). For differentiating atypical PCNSL from GBM, single quantitatively parameters showed moderate performance (AUC, 0.655-0.767). Further combining TBR with ADC min (quantitative model 2) significantly improve the AUC to 0.883. Multiparameter models, incorporating significant quantitative and qualitative MRI features, achieved AUCs of 0.953 (PCNSL vs GBM) and 0.902 (atypical PCNSL vs GBM), significantly outperforming single parameters (all P 's < 0.05).

Conclusions: 68 Ga-pentixafor PET in combination with MRI provides valuable diagnostic information in differentiating PCNSL from GBM, especially for atypical PCNSL.

Purpose of the report: The usefulness of brain 18 F-FDG PET/CT in primary central nervous system lymphoma (PCNSL) remains underexplored. This study investigated whether early metabolic responses in interim brain FDG PET/CT serve as a prognostic indicator of PCNSL treatment outcomes.

Patients and methods: This prospective study included 53 patients with PCNSL who underwent a high-dose methotrexate-based treatment. Brain FDG PET was performed at diagnosis (baseline PET) and after induction chemotherapy (interim PET), assessing interim PET parameters such as the highest maximum standardized uptake value (hSUV max ), sum of SUV max (sumSUV max ), highest tumor-to-normal ratio (hTNR max ), sum of TNR max (sumTNR max ), highest metabolic tumor volume (MTV) (hMTV), and sum of MTV (sumMTV) across all PET-positive lesions.

Results: High interim hTNR max (hazards ratio: 9.76, 95% confidence interval: 1.90-50.11, P = 0.01) was an independently significant predictor of poor progression-free survival in multivariate analysis. Patients with low interim hTNR max (≤1.0) had a significantly longer median progression-free survival than those with high interim hTNR max (>1.0) (25.0 vs 3.6 months, P < 0.001). Incorporating interim MRI-based clinical response assessments and hTNR max allowed the classification of partial response subgroups with markedly different prognoses ( P < 0.001). High interim hTNR max (hazards ratio: 2.76, 95% confidence interval: 1.39-5.48, P = 0.004) was an independently significant predictor of poor overall survival in multivariate analysis.

Conclusions: The hTNR max measurement from interim brain FDG PET scans emerges as an important prognostic marker in PCNSL. These findings underscore the potential of interim FDG PET evaluations to refine response assessments and inform tailored therapeutic strategies.

Abstract: We report the first case of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) evaluated with hypoxic imaging using 18 F-FAZA PET/CT. A healthy woman in her 20s presented to our hospital with seizures, headaches, and vomiting. MRI and CT scans suggested a wide range of differential diagnoses, from neoplastic lesions, such as malignant lymphoma, to inflammatory diseases, such as vasculitis, making her case challenging to diagnose. MOGAD was confirmed by positive myelin oligodendrocyte glycoprotein antibodies, and her condition improved with steroid therapy. The 18 F-FAZA PET/CT findings in this case may aid in understanding the pathogenesis of MOGAD.

Abstract: It is very rare to see fungal arthritis and pyomyositis in immunocompetent patients. Here, we report a case of Scedosporium infection in an immunocompetent patient with interesting 18 F-FDG PET/CT and 68 Ga-NOTA UBI PET/CT findings.

Purpose: Angiogenesis is essential in the development and progression of tumors. This study aimed to investigate the clinical application of 68 Ga-labeled heterodimeric peptide ( 68 Ga-HX01) targeting integrin αvβ3 and CD13 in tumor neovascularization.

Patients and methods: Six healthy volunteers were recruited to study the biodistribution, pharmacokinetics, and radiation of 68 Ga-HX01. Twelve patients with various malignancies were enrolled to seek the preliminary clinical value of 68 Ga-HX01. In healthy volunteers, SUVs of each major organ on 68 Ga-HX01 PET were measured. The clinical data, lesion numbers, and uptake were recorded in patients. The integrin αvβ3 and CD13 expression of the resected tumors was checked via immunohistochemistry staining.

Results: With a mean injected dose of 167.98 ± 26.32 MBq, 68 Ga-HX01 was well tolerated and safe without side effects in 6 healthy volunteers. The radiation absorbed effective dose of 68 Ga-HX01 was 1.94 × 10 -2 mSv/MBq, and the urinary bladder wall held the highest absorbed effective dose (0.15 ± 5.87 × 10 -2 mSv/MBq). In 12 patients with various malignancies, 68 Ga-HX01 PET could clearly visualize the lesions from the surrounding tissues. The SUV max values in tumors were significantly higher than those in the surrounding tissues ( P < 0.05). A positive correlation trend between tumor SUV max and semiquantitative integrin αvβ3 and CD13 expression was determined ( P < 0.05).

Conclusions: For clinical use, 68 Ga-HX01 is safe with low radiation absorbed effective dose. It also indicates the efficiency of dual integrin αvβ3 and CD13-targeting PET radiotracer in tumor diagnosis, which may assist in patient prognosis and selecting eligible patients for antiangiogenic therapy.

Abstract: We report the case of a 71-year-old woman with recurrence of type B3 thymoma in which the diagnostic accuracy has benefited considerably from the additional use of [ 68 Ga]FAPI PET/CT when compared with the standard [ 18 F]FDG PET. [ 68 Ga]FAPI PET/CT confirmed the known lesions with higher lesion-to-background ratio and additionally identified a previously undetected lesion near the FDG-avid apex of the heart. This case demonstrates a potential superiority of [ 68 Ga]FAPI PET/CT in patients suffering from thymoma as detection of local recurrence close to metabolically active organs (ie, liver, heart) is improved. An improved planning of subsequent treatments (ie, lesion delineation for radiotherapy) appears possible.

Purpose: This study aimed to assess the biodistribution and radiation dosimetry of 68 Ga-DATA 5m LM4 in patients with gastroenteropancreatic neuroendocrine tumors.

Patients and methods: Eight patients (5 females and 3 males) with various gastroenteropancreatic neuroendocrine tumors were included in the study. Each patient underwent 3 whole-body PET scans at 10, 60, and 120 minutes after receiving an IV injection of approximately 162.5 MBq of 68 Ga-DATA 5m LM4. Organs considered for dosimetric analysis included the liver, heart, spleen, kidneys, adrenal glands, and lumbar vertebrae (L2 to L4). Dosimetric calculations were performed using the OLINDA/EXM 2.2 software.

Results: Physiological uptake of 68 Ga-DATA 5m LM4 was observed in the pituitary gland, spleen, liver, adrenal glands, and the urinary tract (kidneys and urinary bladder) for all patients. The kidneys received the highest absorbed doses at (4.77E-02 ± 1.49E-02 mSv/MBq). The mean effective dose was 2.61E-03 ± 5.99E-04 mSv/MBq.

Conclusions: 68 Ga-DATA 5m LM4 injection is safe and is primarily excreted through urine, delivering the highest radiation dose to the kidneys.

Abstract: Phyllodes tumors (PTs) are rare fibroepithelial tumors accounting for less than 1% of all breast neoplasms. They are malignant in 20% of cases. Only a few cases of malignant PT metastatic to bone have been reported. We report a case of metastatic malignant PT of the breast involving the greater wing of the sphenoid bone and discuss the radiological findings of 99m Tc-methylene diphosphonate skeletal scintigraphy, SPECT/CT, and 18 F-FDG PET/CT. To our knowledge, this is the first time such a case has been reported in literature.

Abstract: In most cases, prostate cancer spreads locally to the seminal vesicles, via lymphatics to pelvic and abdominal lymph nodes, and hematogenously to the bones. Direct invasion along nerve roots is exceptionally rare but can occur. Here, we present a case with 18 F-DCFPyL PET/CT images showing neoplastic involvement of the lumbosacral plexus in a patient with recurrent prostate cancer.

Background: Even though the introduction of 177 Lu-PSMA-617 RLT represents a major milestone in the treatment of mCRPC, there are still patients who do not respond adequately to this therapy and for whom there are only limited options left. Augmenting 177 Lu-PSMA-617 RLT with the alpha-emitter 225 Ac-PSMA-617 may present an escalating treatment option to increase efficacy. In this study, we aim to evaluate outcome and safety of 225 Ac-PSMA-617 augmentation to 177 Lu-PSMA-617 RLT in patients who present insufficient response to monotherapy with 177 Lu-PSMA-617 RLT.

Patients and methods: The study included n = 51 mCRPC patients enrolled in a prospective registry receiving 177 Lu-PSMA-617 monotherapy and showing insufficient response, followed by initiation of 225 Ac-PSMA-617 augmentation, with adjusted activities depending on individual patient characteristics. Biochemical response, progression-free survival, and overall survival were assessed. Adverse events were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE v.5.0).

Results: After initiation of 225 Ac-PSMA-617 augmentation to 177 Lu-PSMA-617 RLT, 24/51 patients (47.1%) exhibited partial remission, 16/51 (31.4%) stable disease, and 11/51 (21.6%) progressive disease. The median progression-free survival and overall survival rates were 6.3 months and 9.1 months, respectively. The majority of CTCAE gradings remained stable after initiating augmentation. Severe adverse events were rare, and no treatment termination due to side effects was recorded.

Conclusions: 225 Ac-PSMA-617 augmented 177 Lu-PSMA-617 radioligand therapy seems to be an effective escalating treatment option in patients after failure of conventional 177 Lu-PSMA-617 RLT and represents a promising approach balancing antitumor effect and tolerable side effects.