Nuklearmedizin-nuclear Medicine最新文献

Objective: We compared the diagnostic accuracies of ⁶⁸Ga FAPI-04 PET/CT and ¹⁸F-FDG PET/CT for detecting liver metastases (LMs) in patients with different cancer types.

Materials and methods: This retrospective study included 63 patients with liver lesions who underwent ¹⁸F-FDG PET/CT and ⁶⁸Ga-FAPI-04 PET/CT between May 2020 and May 2022. Patients with histopathologically confirmed primary diagnoses, data that could be accessed retrospectively, liver lesions confirmed by biopsy over at least 3-6 months of follow-up (via ultrasonography, CT, magnetic resonance imaging, PET/CT, or laboratory tests) were included. Patients with secondary malignancies or primary liver malignancies, and/or who could not be followed-up, were excluded.

Results: Of the 63 total patients, 34 (54%) were female, and the mean age was 61 (30-92) years. There were 582 LMs in 51 patients and 35 benign liver lesions in 20 (12 patients had only benign and 8 both benign and malignant lesions). Of the 582 LMs, 472 (81.1%) evidenced ¹⁸F-FDG uptake and 572 (98.2%) ⁶⁸Ga-FAPI uptake. The diagnostic accuracies of ⁶⁸Ga-FAPI PET/CT and ¹⁸F-FDG PET/CT were 98% and 82%, respectively (p < 0.001; McNemar test). When the LMs were compared, the maximum standardized uptake (SUVmax) value was significantly higher on ¹⁸F-FDG PET/CT than ⁶⁸Ga-FAPI PET/CT (median: 6.0 vs. 5.4; p = 0.016). However, the LM-to-background ratio (TBR) was significantly higher on ⁶⁸Ga-FAPI PET/CT than ¹⁸F-FDG PET/CT (median: 4.1 vs. 2.1; p < 0.001).

Conclusion: ⁶⁸Ga-FAPI PET/CT detected more LMs than did ¹⁸F-FDG PET/CT, and TBR was significantly higher on ⁶⁸Ga-FAPI PET/CT than ¹⁸F-FDG PET/CT.

A 65-year-old man presented with abdominal bloating, pain, and nausea for 5 days. Abdominal CT revealed a heterogeneous mass with a large area of calcification, and rupture of the mass was seen around the capsulafibrosa. According to pathological examination after percutaneous puncture biopsy, the histopahological and immunohistochemical findings were suggestive of metastatic or primary hepatic osteosarcoma. Whole body bone scintigraphy demonstrated elevated 99mTc-MDP activity in hepatic mass, but no skeletal lesions. The diagnosis of primary hepatic osteosarcoma was finally confirmed. PET/CT showed hepatic mass with heterogeneous high-uptake, and multiple metastases in portacaval lymph nodes, lungs and the third thoracic vertebra were considered.

Purpose: Prostate-specific membrane antigen (PSMA) is present in the proximal tubule cells of the kidneys. This results in high renal tracer uptake in PSMA-PET, which may contain useful information on renal function. As part of the evaluation for [¹⁷⁷Lu]-PSMA therapies, patients undergo PSMA-PET and additional [^99mTc]-mercapto-acetyltriglycine (MAG3) scintigraphy to assess renal function. Aim of this study was to evaluate estimation of renal function with [¹⁸F]-PSMA-1007-PET/CT (PSMA-PET) by comparison to timely MAG3-scintigraphies.

Materials and methods: We retrospectively investigated 73 prostate cancer patients with 93 timely available PSMA-PET/CT, MAG3-scintigraphies and serum creatinine. For determination of split renal function in PSMA-PET/CT, we evaluated the relative unilateral total renal PSMA uptake, i.e. SUV_mean multiplied by the renal volume (SRF_PSMA-TOTAL) and relative unilateral maximal standardized uptake value (SRF_SUV). These were compared to MAG3 split renal function (SRF_MAG3) using Pearson correlation and receiver operating characteristics analysis. For determination of global renal function, correlation of bilateral total renal PSMA uptake with MAG3 tubular excretion rate and serum creatinine was assessed.

Results: SRF_MAG3 was strongly correlated with SRF_PSMA-TOTAL (r= 0.872, p<0.001) and with SRF_SUV (r=0.815, p<0.001). Relevant abnormalities of SRF_MAG3 (unilateral renal function < 25 %) could be detected with sensitivities and specificities of 90% and 92% for SRF_PSMA-TOTAL, and 80% and 95% for SRF_SUV. Measures of absolute renal function were only weakly correlated with bilateral total renal PSMA uptake.

Conclusion: Renal [¹⁸F]-PSMA-1007 uptake allowed to quantify renal split function with good accuracy based on SRF_PSMA-TOTAL or SRF_SUV.

Background:  Despite anti-inflammatory treatment, patients with giant cell arteritis (GCA) experience relapse. We aimed to determine respective relapse predictors focusing on [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG)-PET-based parameters.

Material and methods:  21 therapy-naïve GCA patients received [¹⁸F]FDG-PET/CT. Patients were divided in two groups: those who relapsed during course of disease and those who did not. Median follow up was 15 months. [¹⁸F]FDG-PET/CT was analyzed for visual (PET vascular activity score [VAS]) and quantitative parameters, including Target-to-background-Ratio with liver (TBR_liver) and jugular vein (TBR_jv) serving as reference tissues. In addition, clinical parameters were tested.

Results:  8/21 (38.1 %) had relapse. Clinical parameters could not significantly discriminate between relapse vs no-relapse, including age (p = 0.9) or blood-based inflammatory markers (white blood cell counts [WBC] and c-reactive protein [CRP], p = 0.72, each). PETVAS score could also not differentiate between respective subgroups (p = 0.59). In a quantitative assessment, TBR_jv demonstrated a trend towards significance (p = 0.28). TBR_liver, however, separated between patients with and without relapse (p = 0.03).

Conclusion:  [¹⁸F]FDG PET quantification of vessels may be useful to identify GCA patients prone to relapse during follow-up.

Vertebral osteomyelitis is the third most common form of osteomyelitis in patients over 50 years of age.Whereas prompt (pathogen-directed) therapy is crucially associated with better outcomes, the heterogeneous clinical presentation of disease with unspecific symptoms often delays adequate treatment initiation. Diagnosis requires a careful investigation of medical history, clinical findings and diagnostic imaging, including magnetic resonance imaging and nuclear medicine techniques.Due to its high sensitivity, [¹⁸F]FDG PET/CT is becoming increasingly important in diagnosis and management of spondylodiscitis, especially in the postoperative setting with presence of spinal hardware or other implantable devices in which MRI is limited.

Objective: Local treatments used in metastatic liver tumours efficiently control the disease and survival. Transarterial radioembolisation (TARE) is a safely used locoregional treatment method. We aim to investigate the impact of TARE on different kinds of metastatic liver tumours and the effect of pre-treatment clinical findings.

Material and methods: The patients with metastatic liver tumours referred to our department for radioembolisation were retrospectively evaluated. All patients were given a Y-90 glass microsphere after being selected by the appropriate clinical and imaging criteria, lung shunt fraction levels, vascular investigation, and macro aggregated albumin (MAA) scintigraphy performed in the angiography unit.

Results: Thirty-four (17 women, 17 men) patients were suitable for the treatment. Patients were treated with 115.88±47.84 Gy Y-90 glass Microspheres. The mean survival rate was 14.59±12.59 months after treatment. Higher survival rates were detected in patients who had higher pre-treatment serum albumin levels. The optimum cut-off value of albumin to predict response to treatment was 4 g/dl with 88.89% sensitivity, 62.50% specificity, 72.73% PPV and 83.33% NPV. Furthermore, one unit increase in age increased mortality 1.152 times in our patient group.

Conclusion: Radioembolisation is a safe and efficient method for controlling metastatic liver disease. Albumin levels significantly affect predicting response; higher albumin levels are related to higher survival rates. Furthermore, older age positively correlated with mortality rates in our patient group.

The aim of the study was to evaluate the effect of reduced injected [18F]FDG activity levels on the quantitative and diagnostic accuracy of PET images of patients with non-lesional epilepsy (NLE).Nine healthy volunteers and nine patients with NLE underwent 60-min dynamic list-mode (LM) scans on a fully-integrated PET/MRI system. Injected FDG activity levels were reduced virtually by randomly removing counts from the last 10-min of the LM data, so as to simulate the following activity levels: 50 %, 35 %, 20 %, and 10 % of the original activity. Four image reconstructions were evaluated: standard OSEM, OSEM with resolution recovery (PSF), the A-MAP, and the Asymmetrical Bowsher (AsymBowsher) algorithms. For the A-MAP algorithms, two weights were selected (low and high). Image contrast and noise levels were evaluated for all subjects while the lesion-to-background ratio (L/B) was only evaluated for patients. Patient images were scored by a Nuclear Medicine physician on a 5-point scale to assess clinical impression associated with the various reconstruction algorithms.The image contrast and L/B ratio characterizing all four reconstruction algorithms were similar, except for reconstructions based on only 10 % of total counts. Based on clinical impression, images with diagnostic quality can be achieved with as low as 35 % of the standard injected activity. The selection of algorithms utilizing an anatomical prior did not provide a significant advantage for clinical readings, despite a small improvement in L/B (< 5 %) using the A-MAP and AsymBowsher reconstruction algorithms.In patients with NLE who are undergoing [18F]FDG-PET/MR imaging, the injected [18F]FDG activity can be reduced to 35 % of the original dose levels without compromising.

Background: Imaging devices such as PET/CT are becoming increasingly important in view of the growing range of innovative nuclear medicine diagnostic procedures. Since the procurement and commissioning as well as the ongoing operation of imaging devices leads to comparatively high costs, it is of great interest for clinics and practices to know the number of scans from which the (planned) device operation leads to a profit. In the following, we will introduce the breakeven point analysis and present a calculation tool that users in nuclear medicine clinics and practices can use in everyday operations using PET/CT as an example.

Methods: In the breakeven point analysis, the intersection point is determined from which the organisation- or device-specific revenues exceed the total costs incurred for personnel, material resources, etc. For this purpose, the fixed and variable (planned) cost components for the procurement and operation of the device must be prepared on the cost side and the respective device-related (planned) revenue structure on the revenue side.

Results: The authors present the break-even analysis method with the data processing required for this using the example of the planned procurement or ongoing operation of a PET/CT. In addition, a calculation tool was developed, that interested users can use to prepare a device-specific break-even analysis. For this purpose, various cost and revenue data are discussed, which have to be compiled and processed within the clinic and entered into prepared spreadsheets.

Conclusion: The breakeven point analysis can be used to determine the profit/loss (point) for the (planned) operation of imaging devices such as PET/CT. Users from imaging clinics/practices and administration can adapt the calculation tool presented to their specific facility and thus use it as a basic document for both the planned procurement and the ongoing operational control of imaging devices in everyday clinical practice.