NUCLEAR MEDICINE REVIEW最新文献

Introduction: Nuclear medicine (NM) methods play an important role in the evaluation of renal function in a wide range of clinical indications. The aim of our study was to evaluate the correlation between measured GFR (mGFR) obtained by the three-plasma sample slope-intercept NM method (TPSM) - reference method vs. estimated GFR (eGFR) using Fleming's single plasma sample method (SPSM) at 120 min, 180 min, and 240 min and correlation of reference method with eGFR with camera-based Gates' protocol.

Material and methods: A total of 82 subjects (33 male/49 female) with a mean age of 54.87 ± 15.65 years were included and mGFR value was obtained by the three-plasma sample slope-intercept NM method and eGFR was obtained with Fleming's single sample method. eGFR was also quantified with the camera-based Gates' protocol after i.v. application of [99mTc]Tc-DTPA.

Results: Our study revealed a very strong positive significant correlation between all three SPSMs with the TPSM as the reference method. Between the Gates' method and the TPSM in the group of patients with mGFR ≥ 61-84 mL/min/1.73 m2 and mGFR ≥ 84 mL/min/1.73 m2, a moderate positive statistically significant correlation was obtained.

Conclusions: The SPSM method shows a very strong correlation with the reference and low bias in all three groups of patients and can be routinely used for GFR estimation.

Background: As a result of constantly improving surgical methods, an increasing number of patients have medical devices implanted in the cardiovascular system (including vascular grafts and endografts). Such patients are characterised by their high risk of infectious complications due to the possibility of biofilm formation on implanted material. This work aims to analyse the utility of 2-[18F]FDG PET/CT in diagnosing vascular graft and endograft infections.

Material and methods: The study was undertaken on a group of 58 patients, of whom 34 were in the study group, and 24 were in the control group. The 2-[18F]FDG PET/CT study was conducted in the Nuclear Medicine Department at the University Hospital of Lublin. The inclusion criteria for the study group were the presence of a vascular graft or endograft that encompasses the aorta, and strong clinical suspicion of its infection. The inclusion criteria for the control group were the presence of a vascular graft or endograft in the large arteries and the absence of signs of its infection on 2-[18F]FDG PET/CT, as well as the absence of clinically apparent signs and symptoms during six months of observation after 2-[18F]FDG PET/CT. All patients found in the database that met the criteria were included.

Results: Vascular endografts were more common in the control group than in the study group. However, in the case of infection of the vascular endograft, signs of infection in 2-[18F]FDG PET/CT were more severe. Images in the study group were divided into three groups that represent image patterns based on CT and PET characteristics. The first pattern (P1) was recognised in six patients. The second (P2) and third (P3) were visible in 11 and 17 patients, respectively.

Conclusions: Comparative analysis of the study and control groups demonstrates the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft/endograft infection.

We present a case of a 79-year-old asymptomatic patient with prostate adenocarcinoma, Gleason score 9 (4 + 5), with the initial prostate-specific antigen (PSA) level of 17 ng/mL, treated with radiotherapy and hormonotherapy, who was diagnosed with the rapid growth of PSA levels up to 78.8 ng/mL. Due to suspected bone metastases, first, bone scintigraphy was performed. However, it showed only one intense "hot" lesion in the Th7 projection. This image was not consistent with a high level of PSA, for which reason a computed tomography (CT) scan was performed. It revealed lytic metastasis in Th7 and one more suspicious change in L2, which still was inconsistent with the patient's clinical picture. The patient was referred for [68Ga]Ga-PSMA-11 PET/CT. It showed an uncountable number of foci of increased marker accumulation in bones, mostly without visible change in CT examination. This case showed that the clinical results and suspicions of the advancement of a patient's disease are still the most important data in care and therapy planning.

Background: This study aims to evaluate the performance of a deep learning enhancement method in PET images reconstructed with a shorter acquisition time, and different reconstruction algorithms. The impact of the enhancement on clinical decisions was also assessed.

Material and methods: Thirty-seven subjects underwent clinical whole-body [18F]FDG PET/CT exams with an acquisition time of 1.5 min per bed position. PET images were reconstructed with the OSEM algorithm using 66% counts (imitating 1 min/bed acquisition time) and 100% counts (1.5 min/bed). Images reconstructed from 66% counts were subsequently enhanced using the SubtlePET™ (SP) deep-learning-based software, (Subtle Medical, USA) - with two different software versions (SP1 and SP2). Additionally, images obtained with 66% counts were reconstructed with QClear™ (GE, USA) algorithm and enhanced with SP2. Volumes of interest (VOI) of the lesions and reference VOIs in the liver, brain, bladder, and mediastinum were drawn on OSEM images and copied on SP images. Quantitative SUVmax values per VOI of OSEM or QClear™ and AI-enhanced 'shortened' acquisitions were compared.

Results: Two hundred and fifty-two VOIs were identified (37 for each reference region, and 104 for the lesions) for OSEM, SP1, SP2, and QClear™ images AI-enhanced with SP2. SUVmax values on SP1 images were lower than standard OSEM, but on SP2 differences were smaller (average difference for SP1 11.6%, for SP2 -4.5%). For images reconstructed with QClear™, SUVmax values were higher (average +8.9%, median 6.1%, SD 18.9%). For small lesions with SUVmax values range 2.0 to 4.0 decrease of measured SUVmax was much less significant with SP2 (for liver average -6.5%, median -5.6% for lesions average -5.6%, median - 6.0, SD 5.2%) and showed the best correlation with original OSEM. While no artifacts and good general diagnostic confidence were found in AI-enhanced images, SP1, the images were not equal to the original OSEM - some lesions were hard to spot. SP2 produced images with almost the same quality as the original 1.5 min/bed OSEM reconstruction.

Conclusions: The studied deep learning enhancement method can be used to accelerate PET acquisitions without compromising quantitative SUVmax values. AI-based algorithms can enhance the image quality of accelerated PET acquisitions, enabling the dose reduction to the patients and improving the cost-effectiveness of PET/CT imaging.

Background: Neuroendocrine neoplasms (NENs) are heterogeneous groups of tumours derived from neuroendocrine cells of the ectoderm or endoderm. They are considered rare, with an estimated incidence and prevalence of 6/100,000 and 35/100,000 respectively, and a noticeable upward trend. Radioligand therapy (RLT) using beta-radiation-emitters combined with somatostatin analogues is an effective and relatively safe treatment method. It is usually used as a second-line therapy in case of progressive disease.

Material and methods: In retrospective analysis covering eight years of observation (2015-2023) of patients treated in a single highest-reference NEN centre, a subgroup of 13 who received RLT re-treatment (¹⁷⁷Lu or ¹⁷⁷Lu/⁹⁰Y-mixture) was identified. Epidemiological aspects, renal, hepatic, haematological parameters and chromogranin A serum concentration were analysed.

Results: The median PFS after the first cycle of RLT was 53.8 months (IQR = 19.3). Directly after the second cycle of RLT disease stabilization and progression was observed in 11/13 (84.6%) and 2/13 (15.4%) patients respectively. After the second cycle of RLT median observation time for the study group was 16.2 months. Eight out of 13 patients were reachable for long-term observation and stabilization was confirmed in 62.5 % (5/8), progression in 12.5% (1/8) and death in 25% (2/8) patients. Median survival time in patients with confirmed death was 7 months. During observation, an increase in creatinine concentration with a decrease in glomerular filtration rate (GFR) was noticed, however, the values were at a statistical trend level (p = 0.056; p = 0.071). The increase of liver parameters was statistically, but not clinically significant. The decrease in albumin concentration and fasting glucose concentration were not significant. An increase in chromogranin A concentration correlated, although not statistically, with the progression of the disease. A statistically significant decrease in the number of all bone marrow cell lines was observed. The first RLT cycle caused a higher decrease in blood parameters than the second. There were no differences in PFS or laboratory parameters depending on the radioligand ([¹⁷⁷Lu]Lu-DOTA-TATE vs. [¹⁷⁷Lu]Lu-DOTA-TATE/[⁹⁰Y]Y-DOTA-TATE).

Conclusions: In follow-up after RLT re-treatment stabilization was observed in 62.5%, progression in 12.5% and death in 25% of patients. Decrease of glomerular filtration, and bone marrow parameters resulted from the cumulative adverse effect of RLT, the natural ageing process, and the progression of the disease. Side effects were mainly caused by the first treatment cycle. There was no significant influence on the measured parameters, depending on the radioisotope used. Re-treatment of RLT seems to be a reliable and relatively safe method, thus should be considered in patients who underwent one cycle of RLT and responded to the t

Acrometastases are rare. Less than 0.01% of patients have metastasis in the foot bone. Polyostotic metastasis in the foot is extremely rare. We report a 50-year-old woman who complained of progressive pain and swelling in the right foot after radical right mastectomy for 4 years. [18F]FDG PET/CT demonstrated multiple mixed bone destruction in the right foot with intense [18F]FDG PET/CT uptake. CT-guided calcaneus biopsy confirmed the diagnosis of metastatic breast carcinoma.

The oncophilic nature of [99mTc]Tc-MIBI makes this radiopharmaceutical useful in cancer diagnostics, with particular emphasis on breast cancer. Increased uptake of [99mTc]Tc-MIBI in tests performed for non-oncological indications always raises the suspicion of its neoplasmatic character and requires further clinical diagnostics, which is especially justified in patients with a previous history of cancer. However, the presented case illustrates that focally increased uptake of [99mTc]Tc-MIBI is not always associated with the presence of cancer cells and may result from post-therapeutic changes.

Background: Although not yet involved in the algorithm of thyroid nodules, 99mTc-methoxy-isobutyl-isonitrile ([99mTc]MIBI) scintigraphy may help in the individual diagnostic workup of a thyroid patient, especially where indeterminate fine needle aspiration biopsy (FNAB) is present. The aim of this study was to evaluate the usefulness of [99mTc]MIBI thyroid scintigraphy in the diagnostic algorithm of thyroid nodules, particularly in ultrasound EU-TIRADS 4 or 5 lesions, that cytologically were either indeterminate or benign.

Material and m: ETHODS: A retrospective randomized study, including 42 thyroid patients, with mean age 47 ± 17 years, was conducted. [99mTc]MIBI scan was compared with ultrasound (US) EU-TIRADS criteria, pertechnetate scan, FNAB and histopathological findings for the differentiation of malignant thyroid nodules from benign lesions.

Results: The US mainly detected hypoechoic inhomogeneous presentation of the thyroid nodules (35/42, 83.33%), 4 cases with isoechoic nodules and 2 cases presented with hyperechoic thyroid nodules. Histopathology revealed malignancy in 15/42 (35.71%), while all other patients 27/42 (64.29%) were benign. Visual analysis score showed that patients scored with 1+ and 2+ were statistically significant to be benign, while 13 vs. 10 pts that were visual score 3+ were malignant vs. benign (p > 0.05). Sensitivity was 100%, while specificity was very low 22.22%, PPV was 41.67%.

Conclusions: Even [99mTc]MIBI scan is not routinely used as a daily practice diagnostic tool of thyroid nodules, we will further apply it on a larger group of patients and try to quantify the uptake of the radiotracer to see whether it will help in the diagnostic algorithm of thyroid nodules.

Incidental uptake in [18F]FDG PET/CT is not uncommon, but uptake in the oral and sinonasal regions was less frequently reported. We present a case of incidental focal [18F]FDG PET/CT uptake within the hard palate, which was later revealed to be an ossifying fibroma. We also reviewed some relevant literature and suggested that further investigation may be necessary for some patients with incidental [18F]FDG PET/CT uptake in the oral and sinonasal regions.

Background: To evaluate the effect of patient-related factors such as age, gender, body mass index (BMI), blood glucose (BG), diabetes, serum creatinine and injected dose on 18F-Fluorodeoxyglucose ([18F]FDG) uptake of tumor and normal organs, as well impact of [18F]FDG uptake of tumor on normal organs, in clinical positron emission tomography-computed tomography (PET/CT).

Material and methods: In this retrospective study, data of 200 patients who underwent clinical [18F]FDG PET/CT with (n = 192) and without (n = 8) intravenous contrast was evaluated. Ten target organs and tumor [18F]FDG uptake were measured with a standardized uptake value maximum (SUVmax). Pearson correlation coefficient was calculated for continuous variables while t-test/Wilcoxon rank sum tests were used to compare continuous outcomes. Multivariate linear regression analysis was done to exclude covariates, followed by posthoc multiple linear regression analysis after adjusting the levels of significance.

Results: Significant but weak positive correlation was seen between tumor [18F]FDG uptake with uptake in the pancreas (r = 0.43, p < 0.001) and heart (r = 0.19, p = 0.049), but not other organs. With age, a significant negative correlation was seen with the brain (r = -0.183, p = 0.009) and a positive correlation was seen with the blood pool (r = 0.205, p = 0.003). With BG, significant negative correlation was seen with the brain (r = -0.449, p < 0.0001) and heart (r = -0.15, p = 0.033), while a positive correlation was seen with fat (r = 0.143, p = 0.043). BMI showed a significant positive correlation with [18F]FDG uptake of all organs except the pancreas and heart, as well as tumor. No significant correlation was seen with serum creatinine and injected [18F]FDG dose. Significantly higher uptake was seen in the brain, spleen, and muscles of females. Between obese and non-obese, a significant difference was seen for all organs except for the pancreas and heart, and tumor. Comparison between non-diabetic and diabetic patients showed significant differences only for bone. Multivariate linear analysis adjusting for cofactors showed only BMI (p = 0.0009) and BG (p = 0.0002) to be independently correlated with [18F]FDG uptake. Post-hoc multiple regression analysis showed a significant positive correlation between [18F]FDG uptake of the brain (β = 0.118, p < 0.001), liver (β = 0.02, p = 0.002), and fat (β = 0.01, p < 0.0006) with BMI, and significant negative correlation of brain uptake with BG (β = 0.03, p < 0.0001).

Conclusions: Tumor [18F]FDG uptake has no significant effect on the uptake in organs, except for the pancreas and heart. Age, gender, BMI, and BG, but not creatinine and injected [18F]FDG dose show correlation with uptake in tumor and organs. BG and BMI are independent significant factors, with a positive correlation of BMI with the brain, hepatic and fat uptake, and a negative cor