VAMP1-Related Congenital Myasthenic Syndrome: A Case Report and Literature Review.

Congenital myasthenic syndrome-25 (CMS-25) is an autosomal recessive neuromuscular disorder caused by a homozygous mutation in VAMP1 gene. To date, only eight types of allelic variants in VAMP1 gene have been reported in 12 cases of CMS-25. Here, we report on an 8-year-old boy with motor developmental delay, axial hypotonia, myopathic face, muscle weakness, strabismus, ptosis, pectus carinatum, kyphoscoliosis, joint contractures, joint laxity, seizures, and recurrent nephrolithiasis. He also had feeding difficulties and recurrent aspiration pneumonia. Brain magnetic resonance imaging at 20 months of age showed left focal cerebellar hypoplasia. Genetic analysis revealed a homozygous missense variant of c.202C > T (p.Arg68Ter) in the VAMP1 gene. Treatment with oral pyridostigmine was started, which resulted in mild improvement in muscle strength. Salbutamol syrup was added a few months later, but no significant improvement was observed. This case report presents novel findings such as focal cerebellar hypoplasia and nephrolithiasis in VAMP1-related CMS-25. Consequently, this case report extends the clinical spectrum. Further studies are needed to expand the genotype-phenotype correlations in VAMP1-related CMS-25.

Comparison of body iodine pool assessment methods before radioiodine therapy.

INTRODUCTION AND OBJECTIVES: Radioactive iodine therapy (RAIT) is recommended to reduce the risk of recurrence and metastasis in patients with intermediate-high risk differentiated thyroid cancer (DTC). In preparation for RAIT, stimulation of thyroid-stimulating hormone and reduction of body iodine pool are important for treatment success. For this purpose, patients are asked to reduce their iodine intake before RAIT, and the body iodine pool can be evaluated by measuring iodine excretion in urine before treatment. The aim of our study is to compare the methods used to measure the body iodine pool in the evaluation of the restricted iodine diet (RID) effectiveness applied in the RAIT preparation. PATIENTS AND METHODS: Eighty DTC patients discontinued levothyroxine three weeks before RAIT and followed up with a RID two weeks before treatment. After two weeks of RID, all patients collected their 24-h urine the day before the RAIT date. Patients completed 24-h urine samples on the morning of the RAIT date and also provided a spot urine sample. The estimated 24-h creatinine excretion of the patients was calculated. Estimated 24-h urinary iodine excretion (UIE) was calculated using the spot urine iodine/creatinine (I/C) ratio of the patients. 24-h UIE, iodine concentration in spot urine, I/C ratios in spot urine and estimated 24-h UIE of the patients were analyzed by comparing with each other. RESULTS: In 99% of the patients, RID efficiency was sufficient according to 24-h UIE before RAIT. The mean 24-h UIE was 48.81 micrograms/day (mcg/day) in 24-h urine samples taken from the patients to evaluate the body iodine pool. The patients' iodine concentrations in spot urine, I/C ratios in spot urine, and estimated 24-h UIE were all statistically significantly lower than actual 24-h UIE, which was the reference method (p: 0.026 vs <0.001 vs 0.041). Moderate positive correlation between 24-h UIE and iodine concentration in spot urine (r: 0.440), I/C ratio in spot urine (r: 0.493), and estimated 24-h UIE (r: 0.560) found. The strongest correlation was obtained with the estimated 24-h UIE. CONCLUSION: The estimated 24-h UIE obtained by using the I/C ratio in spot urine can be used practically and safely as an alternative to UIE in 24-h urine, which is the gold standard method for evaluating body iodine pool.

The variation of quantitative parameters and Deauville scores with different reconstruction algorithms in FDG PET/CT imaging of lymphoma patients.

INTRODUCTION AND OBJECTIVES: 18F-FDG PET with the Deauville score (DS) is a unique semiquantitative method for lymphoma. However, type of standard uptake values (max, mean, and peak) reconstruction algorithms could affect DS. We compared the Bayesian Penalized Likelihood reconstruction algorithm (BPL) with Ordered Subsets Expectation Maximization (OSEM) on quantitative parameters and DS in lymphoma. We investigated the effect of the size of the lymph node on quantitative variation. PATIENTS AND METHODS: Raw PET data of 255 lymphoma patients were reconstructed separately with Q.Clear (GE Healthcare), a BPL, and SharpIR (GE Healthcare), an OSEM algorithm. In both images, each patient's liver, mediastinal blood pool, and SUVs (SUVmax, SUVmean, and SUVpeak) of a total of 487 lesions selected from the patients were performed. DSmax, DSmean, and DSpeak were compared. RESULTS: In our study, DS increased significantly with BPL (p < 0.001), and the DS increased to 4-5 in thirty patients evaluated as 1-2-3 with OSEM. It was found that the quantitative values of the lymph nodes increased statistically with BPL (p < 0.001), and the liver from the reference regions were significantly decreased (p < 0.001). In addition, difference in lymph node was independently associated with size of lesion and was significantly more pronounced in small lesions (p < 0.001). The effects of BPL algorithm were more pronounced in SUVmax than in SUVmean and SUVpeak. DS-mean and DS-peak scores were less changed by BPL than DS-max. CONCLUSION: Different reconstruction algorithms in FDG PET/CT affect the quantitative evaluation. That variation may affect the change in DS in lymphoma patients, thus affecting patient management.

Incidental Spleen Cyst Mimicking Thyroid Carcinoma Metastasis: False-positive Uptake on Radioiodine Whole Body Scan.

In differentiated thyroid cancer, radioiodine therapy and whole body scans (WBS) are integral part of disease management. We present the case of a 33-year-old woman with multifocal thyroid carcinoma who was treated with radioiodine. Post-treatment WBS scintigraphy showed focal increased I-131 uptake in the spleen, although stimulated thyroglobulin level was not suggestive of distant metastasis. Dynamic magnetic resonance imaging performed later revealed that the finding was an incidental splenic cyst. Radioiodine uptake is not specific to the thyroid tissue. Benign pathologies showing increased radioiodine uptake should be considered in cases with splenic radioiodine accumulation in WBSs.

Is a strict restricted-iodine diet necessary for preparation of radioactive iodine therapy?

OBJECTIVE: A restricted-iodine diet (RID) increases the effectiveness of radioiodine therapy (RAIT) by decreasing the body's iodine pool, especially in iodine-rich regions. However, there is no consensus on the RID that should be applied in iodine-deficient areas. This study aims to assess the effect of strict and flexible RID before RAIT. METHODS: For the study, 144 patients were randomized into the strict or flexible RID group. All patients stopped levothyroxine before RAIT and followed a RID. After 2 weeks of RID, 24-h urine samples were taken. The urinary iodine excretion was compared. In 52 of 144 patients, the spot urine samples were taken before and after RID. The reduction in urinary iodine excretion was compared according to the iodine/creatinine ratio. RESULTS: Our study included 47 males and 97 females with a mean age of 45 years. After RID in the 24-h urine samples, the mean iodine level was 47.9 µg/day, and both protocols were sufficient to reduce the body iodine pool. There was no significant difference between the strict and the flexible group, 43.06 and 52.89 µg/day (P:0.147). The reduction in urinary iodine excretion was not statistically different in both groups according to spot urine samples (68.20 vs. 60.53%; P:0.377). CONCLUSION: The flexible RID protocol that less disrupts the patient's quality of life can be preferred for RAIT preparation in iodine-deficient countries.

The efficiency of hybrid perfusion SPECT/CT imaging in the diagnostic strategy of pulmonary thromboembolism.

OBJECTIVE: Ventilation/perfusion single photon emission computed tomography (V/Q SPECT) is recommended as a reference radionuclide method in pulmonary thromboembolism (PTE) diagnosis. However, there is some logistic, economic, and infectious concern about the study's ventilation part. This study aimed to evaluate the effectiveness of hybrid perfusion SPECT with a low dose CT method in the diagnostic strategy of PTE. MATERIAL AND METHODS: Two physicians reviewed 305 patients' data for this retrospective study. All patients had Q SPECT/CT data as initial imaging, and Ventilation SPECT was added to the selected patients' algorithm. The diagnostic performance and inter-observer agreement were determined for both Q SPECT and Q SPECT/CT methods. The final diagnosis was made by clinical decision with all tests and follow-up for at least 6-month. RESULTS: The majority (92%) of our study group were correctly diagnosed with the Q SPECT/CT method with excellent inter-observer agreements (κ=0.914). The sensitivity, specificity, and accuracy of methods were as follows; 92.2%, 76.3%, and 80.3% for Q SPECT; 96.1%, 94.5%, and 98.8% for Q SPECT/CT (P<0.001). The ventilation scan was applied to 29% (n=88) of the study group. It is prominent in 21/88 patients whose Q SPECT/CT result was non-diagnostic or discordant with clinical probability. CONCLUSION: Q SPECT/CT recommended as the initial radionuclide imaging in PTE diagnosis, with high diagnostic accuracy and inter-observer agreement. Ventilation scans can be optimized according to Q SPECT/CT results avoiding unnecessary irradiation and other potential adverse effects, including infectious risk in the current pandemic context.

Comparison of 99mTc-MIBI planar scintigraphy, SPET/CT and ultrasonography in detection of parathyroid adenoma in patients with primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is a common endocrine disease that is caused by a single adenoma in most of the cases. Surgical management is the mainstay and definitive treatment for parathyroid adenoma (PA). Minimally invasive surgical techniques are as effective as bilateral neck exploration with a lower risk of complications and better cosmetic results in patients with solitary PA. Accurate preoperative localization with imaging modalities is paramount for determining patients candidate for minimally invasive surgery. In this study we aimed to evaluate the diagnostic performance of technetium-99m-methoxyisobutylisonitrile ( 99mTc-MIBI) planar scintigraphy (PS), single photon emission tomography/computed tomography (SPET/CT) and ultrasonography (US) in patients with PHPT. MATERIAL AND METHODS: Fifty-eight patients with biochemical evidence of PHPT who underwent pre-operative imaging with parathyroid scintigraphy and US for detection and localization of PA and proceeded to surgery were included in the study. All patients underwent dual phase 99mTc-sesta MIBI parathyroid scintigraphy (early and delayed planar images and delayed SPET/CT). Data analysis was performed to evaluate the sensitivity, specificity, diagnostic accuracy and PPV of planar images, SPET/CT and US alone and combined US and SPET/CT. Histopathology was used as gold standard. RESULTS: Sensitivity, specificity, PPV and diagnostic accuracy for detection of PA, 80,4%, 42,8%, 91,1% and 75,8% for PS; 80,4%, 57,7%, 91,1% and 77,5% for delayed SPET/CT; 88,2%, 85,7%, 97,8% and 87,9% for US and 94,1%, 71,4%, 96% and 91,3% for SPET/CT+US. Combined US and SPET/CT has been shown to increase sensitivity and diagnostic accuracy. The overall sensitivity of PS and SPET/CT didn't vary however additional information which is helpful for planning minimally invasive surgery gained from tomographic images. CONCLUSION: The combined use of US and SPET/CT has incremental value in accurately localizing PA over either technique alone. In the preoperative assessment of patients with PHPT combination of imaging methods allows selection of patients who would be suitable for minimally invasive surgery.