فهرست مطالب yalda salehi

Dopamine transporter (DAT) receptors are reduced in the striatum in dementia of Lewy body (DLB) but normal in Alzheimer’s disease (AD). We assessed the diagnostic accuracy of TRODAT-1 imaging to differentiate patients with DLB from AD. Patients with DLB or AD underwent SPECT TRODAT imaging by [99mTc]Tc-TRODAT-1. Visual interpretation and quantification analyses were done. The activity of the right and left caudate nucleus (CN), putamen (P), striatum (S) as a whole, background (BG), and occipital area (OC) were calculated in addition to the ratio of right and left CN/OC, P/OC, and S/BG. Absolute right and left value difference of the striatum (∆S), putamen (∆P), and caudate (∆CN) to OC or BG were also calculated. The diagnostic accuracy of the visual and quantitative method were compared between patients with AD and LBD. The area under the ROC curve (AUC) was analyzed. Twenty-five patients (15 DLB and 10 AD) were included. Scans were visually interpreted as DLB, AD, and non-diagnostic in 11, 13, and one patients, respectively. Sensitivity, specificity, and accuracy of the scan were 57.1% (28.9-82.3), 70% (34.8-93.3), and 62.5% (40.6-81.2), respectively. CN/OC, P/OC, and S/BG in the left, right, and bilaterally were statistically same between two groups. The AUC of ∆CN/OC was 70.7%.  The optimal cut-off value for ∆CN/BG to diagnose DLB was 6.6% with a sensitivity, specificity, and accuracy, of 86.7%, 50%, and 72.0%, respectively. The [99mTc]Tc-TRODAT-1 imaging has limited diagnostic accuracy for discrimination of DLB and AD patients.

Thyroid cancer is the most common endocrine malignancy in the world; however, these patients usually experience a high survival rate if they receive appropriate and timely treatment. Meanwhile, patients classified as having differentiated thyroid cancer with high thyroglobulin and negative iodine scan [Differentiated thyroid cancer with thyroglobulin elevation and negative iodine scintigraphy (TENIS)] are always considered a diagnostic-therapeutic challenge.

We conducted a comprehensive literature search of published papers in the PubMed/MEDLINE database regarding nuclear imaging in differentiated thyroid cancer with thyroglobulin elevation and negative iodine scintigraphy. We included all human studies in this field.

In this review, we examined four major groups of imaging studies aimed at identifying GLUT, SSTR, PSMA and FAP receptors in patients with TENIS. The diagnostic rate of 2-[18F]FDG PET/CT in these patients has been reported as 63-81% based on various studies. Also, [68Ga]Ga-DOTATATE PET/CT, [68Ga]Ga-PSMA PET/CT and [68Ga]Ga-FAPI PET/CT scans have shown good results in these patients.

[68Ga]Ga-FAPI PET/CT imaging has the highest diagnostic rate among these patients. Given the theranostic capability of FAPI and the numerous complications and limited inclusion criteria for treatment with tyrosine kinase inhibitors, it has been the next step in the treatment of patients with TENIS. Therefore, more extensive studies in this field are warranted.

2-[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (2-[18F]FDG-PET/CT) is implemented in papillary thyroid cancer (PTC) patients with elevated Thyroglobulin (Tg) and negative Iodine-131 whole-body scan (131I-WBS). Here, we evaluated the impact of TSH stimulation after levothyroxine withdrawal on the detection rate of 2-[18F]FDG-PET/CT. A prospective study was performed on 60 PTC patients, presented with negative 131I-WBS and elevated or unjustifiably high Tg. 2-[18F]FDG-PET/CT was performed in 30 patients while they were on levothyroxine therapy (unstimulated-TSH [uns-TSH]) and after Levothyroxine withdrawal in the other 30 patients (stimulated-TSH [s-TSH]). Results of the two groups were compared using nonparametric tests. Receiver operating characteristic curve was used to find Tg cutoff values for predicting positive scan results. Overall, 2-[18F]FDG-PET/CT was positive in 63.3% of the patients, 80% (24/30) in s-TSH and 46.7% (14/30) in uns-TSH group. The detection rate was higher in s-TSH group (p=0.007). It was still significant in multiple regression analysis (p=0.041). In uns-TSH group, 2-[18F]FDG-PET/CT was more often positive in patients with higher uns-Tg level (p=0.002). An uns-Tg level of ≥19.00 ng/mL predicted positive results with the sensitivity of 0.786 and specificity of 0.750 (area under curve=0.819). Although statistically insignificant (p=0.055), s-Tg was higher in patients with positive 2-[18F]FDG-PET/CT studies in the s-TSH group. No relation was demonstrated between TSH and anti-Tg-antibody levels and 2-[18F]FDG-PET/CT positivity. TSH-stimulation after levothyroxine withdrawal might enhance the detection rate of 2-[18F]FDG-PET/CT in PTC patients. Additionally, 2-[18F]FDG-PET/CT is more often positive in patients with higher Tg levels.

Nuclear medicine technicians would receive unavoidable exposures during the preparation and administration of radiopharmaceuticals. Based on the staff dose monitoring, the dose reduction efficiencies of the radiation protection shields and the need to implement additional strategies to reduce the staff doses could be evaluated. In this study, medical staff doses during the preparation and administration of Tc‑99 m, I‑131, and Kr‑81 radiopharmaceuticals were evaluated. The dose reduction efficiencies of the lead apron and thyroid shield were also investigated. GR‑207 thermoluminescent dosimeter (TLD) chips were used for quantifying the medical staff doses. The occupational dose magnitudes were determined in five organs at risk including eye lens, thyroid, fingers, chest, and gonads. TLDs were located under and over the protective shields for evaluating the dose reduction efficiencies of the lead apron and thyroid shield. The occupational doses were normalized to the activities used in the working shifts. During preparation and injection of Tc‑99 m radiopharmaceutical, the average annual doses were higher in the chest (4.49 mGy) and eye lenses (4 mGy). For I‑131 radiopharmaceutical, the average annual doses of the point‑finger (15.8 mGy) and eye lenses (1.23 mGy) were significantly higher than other organs. During the preparation and administration of Kr‑81, the average annual doses of the point‑finger (0.65 mGy) and chest (0.44 mGy) were higher. The significant dose reductions were achieved using the lead apron and thyroid shield. The radiation protection shields and minimum contact with the radioactive sources, including patients, are recommended to reduce the staff doses.

The aim of the present study was to investigate the added value of F-18 fludeoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) compared with conventional imaging modalities for the evaluation of locoregional and distant sites of recurrence in breast cancer patients.

From May 2013 to September 2016, 109 patients with suspected recurrent breast cancer who underwent conventional imaging and F-18 FDG PET/CT with an interval of 6 weeks were consecutively enrolled (mean age: 52.66 years; range: 29-79). Histopathologic results and clinical follow up based on the gold-standard imaging modality or serial imaging were considered as the reference for verification of F-18 FDG PET/CTfindings.

Of 109 patients, 81 were found to have at least one site of recurrence (74.31%). Local recurrence was correctly identified in 32/32 patients following PET/CT, which was higher than that on conventional imaging (20/32, 62.5%). PET/CT detected 27 additional nodal metastases compared with conventional imaging (59 vs. 32, 45.76%), most frequently in the hilar/mediastinal region (n=27), followed by the supraclavicular lymph nodes (n=20, 62.5%), internal mammary lymph nodes (n=6, 18.77%), and axillary basin (n=6, 18.77%). Additional sites of distant metastasis were identified in 41 patients (37.61%) following F-18 FDG PET/CT imaging, 48.78% of which were localized in the skeletal system (n=20), 21.95% in the liver (n=9), 12.19% in the lungs (n=5), 12.19% in the brain (n=5), and 4.87% in the adrenal glands (n=2).

F-18 FDG PET/CT serves as a useful supplement to conventional imaging techniques by identifying additional sites of disease recurrence in patients with breast cancer, which may change the preferred treatment strategy, particularly in regions that are not routinely evaluated by conventional imaging.

This study aimed to compare the recurrence rate of breast cancer between women treated with breast-conserving therapy (BCT) with/without radiotherapy and those treated with total mastectomy using 18F-fluorodeoxyglucose 18 positron emission tomography/computed tomography (F-FDG PET/CT).

The current study retrospectively included 588 patients suffering from breast cancer who had been referred to the PET/CT department of Masih-eDaneshvari Hospital in Tehran between April 2013 and September 2019. Data of all female patients with breast cancer were extracted from the recorded hospital files. Based on the treatment plan, patients were divided into two groups: BCT with/without radiotherapy (n=168) and total mastectomy (n=420). Local, 18 locoregional, and distant metabolically active lesions were determined in F-FDG PET/CTand compared between groups.

BCT and total mastectomy were comparable regarding local (28.5% vs. 25.7%, P=0.200) and locoregional (21.4% vs. 22.8%, P=0.712) recurrence, while distant recurrence was significantly higher with total mastectomy (88.5% vs. 64.2%, P<0.001). Also, lymph node invasion (42.9% vs. 60%m P<0.001) and positive PET/CT(78.5% vs. 88.5%, P=0.002) were significantly higher with total mastectomy. According to multivariate analysis, age, clinical stage, and positive margin are independently correlated with the rate of distant metastasis.

According to our analysis, breast-conserving therapy could be a suitable choice of surgery in selected patients since local and locoregional recurrence rate did not significantly differ between patients who underwent breastconserving surgery compared to those who were treated with total mastectomy. Higher rate of distant metastasis in patients with total mastectomy seems to be influenced by many confounding variables such as age, higher stage of diagnosis and positive margin rather than type of surgery.

Myocardial perfusion imaging (MPI) is an important imaging modality in managing patients with cardiovascular disease. MPI has a significant role in diagnosis and management of cardiovascular disease; however it is subjected to different artifacts. Combining pharmacologic stress with submaximal exercise reduces side effects, improves image quality, and enhances the detection of ischemia, compared with suboptimal exercise or vasodilator stress alone.
97 patients (62 males and 35 females) which were randomly allocated into two groups were studied using gated single-photon emission computed tomography (SPECT) imaging. The patients were randomly allocated into two different groups: dipyridamole or dipyridamole combined with submaximal exercise group. Subsequently, they were imaged at 15, 60, 120, and 180 minutes after radiotracer injection.
97 patients with an average age of 57.1 were compared 15, 60, 120 and 180 minutes after radiotracer injection. Comparing dipyridamole and dipyridamole submaximal exercise group a significant difference in target areas (myocardium, inferior and lateral wall) count ratio to both liver and colon count ratio was observed (P A protocol that combines submaximal exercise with dipyridamole stress is highly effective in improvingthe average count ratio of myocardial walls compared to visceral activity.

A 45-year-old woman presented with a headache and visual complaints. Brain MRI revealed a large mass in the right occipital cortex. The tumor was surgically removed and pathological examination showed papillary carcinoma originating from thyroid gland. She had a history of thyroid surgery 27 years ago indicating papillary thyroid cancer with central neck lymph node involvement followed by no additional treatments. CT scan showed a mass in the right kidney and multiple liver cysts. She was referred and treated with curative dose of radioiodine. A post therapeutic iodine scan showed accumulation of the tracer in the right kidney and disseminated uptake in the lungs and neck, with no focal uptake in the liver. To increase iodine accumulation in the lungs with curative intention, the right kidney was surgically resected. Forty-five days after nephrectomy, the patient received her second dose of radioiodine. In the second post therapy scan, the uptake in the lungs and neck was significantly enhanced. The ratio of lungs to whole body uptake was 17.2% and 46.2% in the first and second post therapeutic scan, respectively. Not only unilateral kidney metastasis from PTC is rare incidentally noticed non-metastatic multiple liver cysts in this patient are interesting to report, also the benefit from metastasectomy of asymptomatic visceral metastasis is documented. Such a visceral metastasectomy could result in optimal radiation to other sites, being lung metastases in this case.

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare migratory skeletal disorder with non-infectious inflammatory etiology which usually causes bone pain in children and adolescents. Intermittent periods of exacerbation and remission are usually noted during the course of the disease. It is a multifocal bone disease usually involving the metaphyses of long bones. The clinical and Paraclinical findings are non-specific, and indeed CRMO is a diagnosis of exclusion based on multiple criteria.
We present a 6-year-old boy with multiple periods of fever, systemic inflammation and bone pain since he was 2 years old, hospitalized multiple times, received antibiotics and finally diagnosed as a CRMO case.
CRMO should be diagnosed according to a variety of clinical and paraclinical findings. In children and adolescents with multiple bone lesions and lytic lesion, one of the differential diagnoses that should be considered is CRMO.

Asymptomatic diabetic patients are at increased risk of cardiovascular complications. Myocardial perfusion scan may be effective in risk evaluation in this population. 106 asymptomatic diabetic patients (age: min: 37, max: 82, mean: 57.73±8.88), including 56 females (52.8%) and 50 males (47.2%) were enrolled in the study. Myocardial perfusion scintigraphy was performed by Gated Single Photon Emission Computed Tomography (Gated-SPECT) method. Perfusion and function status was evaluated by qualitative and semi-quantitative parameters. By visual analysis totally 40 out of 106 patients (37.7%) showed abnormal scan. From which, 26(24.5%) showed involvement in one, 13(12.3%) in two, and 1(0.9%) in all three vessel territories. By semi-quantitative method, from 103 patients, 28 (27.2%) were abnormal and 75 (72.8%) were normal. From all the asymptomatic diabetic patients, 11 patients (10.4%) had dilated left ventricles. Transient Ischemic Dilation (TID) was noted in 10 patients (9.4%), and Transient Right ventricle visualization in 7 patients (6.6%). Heart failure (EF<45%) was observed in 14% of asymptomatic diabetic patients. From underlying factors, long duration of diabetes disease correlated to abnormal myocardial perfusion imaging (MPI) findings (Odds Ratio: 2.77; CI: 1.07-7.12). Severe coronary artery disease leading to the pattern of severe ischemia or infarction in MPI, was significantly higher in men than women (P=0.05). Also smoking correlated with higher involvement of LAD coronary artery (P=0.011) and as compared with RCA territory (P=0.079). In asymptomatic diabetic patients myocardial perfusion scintigraphy can be used in early diagnosis of coronary artery disease (CAD) and can be suggested as screening study in these patients.