Background: Thyroid nodules are of the most common Thyroid diseases found in about half of adults.  Diagnosis of nodules is clinically important because of the risk of cancer. Thyroid gland radionuclide scanning with 99mTcO4 helps the physician to choose better approach to the disease, knowing the activity of the nodule. Neck physical examination before scintigraphy and using a piece of lead marker specifies the location of the nodule in the scintigram to give a more distinct interpretation of the report of the scan.Methods: 117 patients with Thyroid nodules referred to Seyyed Alshohada Hospital Nuclear Medicine Center (Isfahan, Iran) during 2012-2013 were studied. The patients underwent scanning with 99mTcO4 once; the next time, physical examination of the neck was done and then, scanning was applied; and for the last time, we put a lead marker on the palpated nodule in physical examination, then did the radionuclide scanning. The reports of three scanning tests were compared together.Findings: Regarding chi-square test, physical examination of neck and using a lead marker on the palpated Thyroid nodule affected the reporting of the scintigram and caused reduction of the falsepositive results in both cold and warm nodules (P<0.05). Also regarding to Wald test, using both mentioned methods resulted in less mistakes in interpretations of the reports of the Thyroid scanning.Conclusion: This study showed that, as a simple cost effective method, physical examination of Thyroid gland and using lead marker through scintigraphy may be useful in diagnosis of Thyroid nodules.

Background: 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. Materials and Methods: 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. Results: 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. Conclusion: [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.

Background Congenital hypoThyroidism (CH) may cause alterations in the child's global development. The current study aimed to screen the global development of children with and without congenital hypoThyroidism, focusing on communication, and cognitive abilities and to investigate the influence of illness severity, clinical history, and treatment factors in the evaluated results. Materials and Methods A case control study was conducted on 20 children with early-treated congenital hypoThyroidism (CH), and controls without CH (n=100), both groups were matched for age and sex. Patients were subjected to a protocol of assessment applied in Pediatric and Phoniatrics Unit Sohag, Egypt. Assessments included detailed history and medical data, language development testing, intelligence quotient (IQ). According to TSH and T4 levels, case group was divided into controlled group and uncontrolled group. 99m pertechnetate scintigraphy of Thyroid (Tc-99m TS) was recommended for all CH children. Results Children’ s ages ranged between 3-7 years with a mean age of (4. 6 ± 1. 9year). There were statistically significant differences between study and control group in presence of middle ear effusion, delayed language development, IQ scores (p<0. 001). Interestingly, there was a negative correlation between IQ test and total language age with TSH level (r =-0. 06, p= 0. 004; r =-0. 4, p=0. 06), respectively. Tc-99m pertechnetate scintigraphy of Thyroid confirmed transient CH diagnosis in three cases. Conclusion Despite early treatment in the studied CH children, language and cognitive skills impairments were detected. The magnitude of these impairments related significantly to TSH values and regularity of hormone replacement therapy. TS confirmed transient CH diagnosis in three cases, replacement therapy stopped in those children.

Introduction: To analyze the clinical features, diagnosis, management and clinical outcomes in the patients with ectopic Thyroid in a tertiary care hospital. Materials and Methods: This was a retrospective study which included eight cases of ectopic Thyroid presented in the outpatient clinic. Their medical records were reviewed for clinical presentation, imaging modalities used, biochemical tests and outcomes of the management was analyzed. Results: Total eight patients were included in the study, of which five were females and three were males, within the age range of 6-44 years. Painless neck swelling was the predominant complaint, which was observed in the seven (87. 50%) patients. Total 6 (75%) patients had normal Thyroid function test and 2 (25%) patients had features of hypoThyroidism. Three patients underwent surgery and three patients needed hormonal replacement. Follow-up was advised for three patients. Post-treatment follow-up of all the patients was conducted for 24 months and no significant progression/recurrence/malignant transformation of the disease was seen in any of the patients. Conclusion: Being a rare disorder, timely diagnosis and management is important to avoid complications and for better clinical outcomes.

Background and aim: Nowadays, Thyroid exposure is a major concern in skull radiological imaging. The aim of this study was to evaluate Thyroid exposure in brain CT-scan and skull X-ray, using different levels of Kvp (Kilovoltd peak) and mA, with and without Thyroid shield.Methods: In this descriptive- analytic study, 350 outpatients were selected randomly. Two TLD-100 chips (Thermo Luminescence Dosimeter) were placed on the Thyroid of each patient. Three levels of mA were applied in brain CT-scan (210 patients) and two levels of Kvp were used in routine skull X-rays (140 patients). The experiments were performed with and without Thyroid shield. The TLDs were read and the statistical analysis was performed using student-t test.Results: During brain CT-scan, decreasing current intensity from 150 to 125 mA, significantly decreased the Thyroid exposure from 101±9.38 to 82.2±8.04 mili rem (P<0.01). Using a Thyroid shield extremely reduced the Thyroid exposure to 29±5.83 mili rem (P<0.01). In routine skull x-rays, increasing voltage from 60 to70 Kvp, significantly decreased the Thyroid exposure from 72.6±7.74 to 67±8.41 mili rem (P<0.05). Moreover, using the Thyroid shield remarkably reduced the Thyroid exposure to 19.6±1.82 mili rem (P<0.05). Conclusions: Using lower levels of mA in brain CT-scans and higher levels of Kvp in skull X-rays, decrease Thyroid exposure. Furthermore, using Thyroid shield during X-ray examinations of the skull remarkably reduces Thyroid exposure.

Background and objective: Nowadays, irradiation Thyroid is very important as an acute organ in CT scans of the brain. Due to the increasing usage of CT scans for diagnosing diseases, the purpose of this Research is to evaluate the received dose from the eye and Thyroid in brain CT scans. Methods: In this research, while performing CT scan of the brain for irradiation of Thyroid and eye were examined in phantom and patients by using Thermo luminescence Dosimetry dosimeter in Shahid Modares Hospital. The dosimeters were placed on the surface of the organs in the X-ray field. Results: In this study, the absorbed dose of sensitive eye and Thyroid was read by the reader in terms of Nanocollen and then converted to mSv by using a calibration curve. In the 3 patient's brain CT scans, the average of received dose from the left eye was 29. 13 mSv, the average of received dose from the right eye was 27. 51 mSv and the average of received dose from Thyroid was 46. 08 mSv. In 3 phantom brain CT scans, the average received dose from the right eye is 26. 35 mSv, the average received dose from the left phantom eye is 25. 71 mSv and the average received dose from the phantom Thyroid is 35. 22 mSv. Conclusion: According to the results, the received dose in patients and phantom are numerically close to each other. It is suggested that phantoms be used instead of the patient in dosimetry research.

Background: Induction of radioadaptive responses in cells pretreated with a low dose radiation before exposure to a high dose is well documented by many investigators. The aim of this study is to determine the frequency of chromosomal aberration in peripheral blood lymphocytes of patients treated by radioiodine (131I) for hyperThyroidism, with or without previous Thyroid scan with 99mTc.Materials and Methods: Venous blood samples were obtained from 35 patients one month after radioiodine therapy and cytogenetically evaluated using analysis of metaphase in two groups. The first group (n = 15, 13 females and 2 males, mean age= 44.7 ±11.5 years and mean weight 74.4±7.9 Kg) received 5 mCi 99mTc for Thyroid scanning 38.6±19.9 days before radioiodine therapy with 10.4 ± 3.4 mCi 131I. The second group (n = 20, 14 females and 6 males, mean age = 41.0 ± 10.8 years and mean weight = 68.1±9.2 Kg) didn/’t have history of Thyroid scanning. We also studied a control group (n = 29, 11 Females and 8 males, mean age = 33.7±7.4 and mean weight = 70.0±8.8 Kg) who didn/’t have any history of diagnostic or therapeutic and also occupational exposure.Results: The mean frequency of total chromosomal aberrations in the first and second groups and controls were 1.46 ±1.55, 1.65 ± 1.62 and 0.93 ± 0.92 respectively. Results also showed that the mean frequency of total chromosome aberration in two groups were higher than controls and significantly higher in patients who had not received 99mTc compared those who had undertaken Thyroid scan before radioiodine therapy (p=0.03).Conclusion: These findings may indicate the fact that the radiation dose received from 99mTc could induce resistance to subsequent higher radiation dose of 131I in peripheral blood lymphocytes and it might be due to cytogenetic radioadaptive response.

Objective(s): We investigated a frequency of lower extremity uptake on the radioactive iodine (RAI) whole body scan (WBS) after RAI treatment in patients with differentiated Thyroid cancer, in order to retrospectively examine whether or not the frequency was pathological.Methods: This retrospective study included 170 patients with Thyroid cancer, undergoing RAI treatment. Overall, 99(58%) and 71(42%) patients received single and multiple RAI treatments, respectively. Post-therapeutic WBS was acquired after 3 days of RAI administration. For patients with multiple RAI treatments, the WBS of their last RAI treatment was evaluated. Lower extremity uptake on post-therapeutic WBS was classified into 3 categories: bilateral femoral uptake (type A), bilateral femoral and tibia uptake (type B), and uptake in bilateral upper and lower extremities (type C). Then, the patients with RAI uptake in the lower extremities on WBS were analyzed with clinical parameters.Results: Overall, 99 patients (58%) had the extremity uptake on their post therapeutic RAI WBS. As the results indicated, 42, 53, and 4 patients had type A, type B, and type C uptakes, respectively. Lower extremity uptake was significantly associated with younger age, not only in subjects with multiple RAI treatments but also in all the patients (P<0.05). Accumulation in patients with multiple RAI treatments was more frequent than patients with single RAI treatment (P<0.05). Lower extremity uptake was not associated with counts of the white blood cell count, hemoglobin level, platelet count, estimated glomerular filtration rate, effective half-time of RAI, serum TSH level, and anti-Tg concentration.Conclusion: About half of the patients had lower extremity uptake on the post therapeutic RAI WBS, especially younger patients and those with multiple courses of RAI treatment. Bilateral lower extremity’s RAI uptake on the post therapeutic WBS should be considered as physiological RAI distribution in bone marrow.

In this in vivo study, 120 adult patients were selected by BMI factor (30 patrents in each method) for measuring Thyroid dose. CT scan methods included conventional CT and spiral CT with three different pitch factors (1.2, 1.5, 1.7). By use of TL dosimetry, Thyroid dose due to scattered radiation in thorax CT scan was measured and the mean of values in each method compared by t-test with reliability of 95% (α=0.05). Dose values also normalized by BMI length of scan (L), patient weight (W). BMI and length of scan together and compared by t-test with reliability of 95% (α =0.05). Results indicates spiral CT with pitch factor greater than one, reduces Thyroid dose in comparison of conventional CT and also increase of pitch factor decreases Thyroid dose.

Background and Objective: Differentiated Thyroid Cancer (DTC) is the most common endocrine malignancy with the fastest growing rate worldwide. The aim of this study is to investigate the prevalence of distant metastases in whole-body scans after iodine therapy in DTC patients with low and intermediate-risk and to evaluate its diagnostic role. Methods: In this retrospective cohort study, patients with DTC who underwent total Thyroidectomy and were referred for Radioiodine Remnant Ablation (RRA) to the nuclear medicine department of Shahid Beheshti Hospital were included in the study. According to ATA guidelines, patients were divided into two groups with low risk level (LR) and intermediate risk level (IR) and were evaluated for distant metastasis by whole-body scan after iodine treatment with a Single-Head Gamma Camera. Findings: Out of 1039 patients included in the study, 149 (14.3%) were men and 890 (85.7%) were women. Thyroid remnant was present in whole-body scan after iodine treatment in 1030 patients (99.1%). Of these patients, 713 (68.6%) were in the LR group and 326 (31.4%) were in the IR group. The presence of cervical lymph node metastasis was detected in 69 people (LR:28, IR:41), mediastinal involvement in 11 people (LR:3, IR:8), lung metastases in 11 people, and bone metastasis in 3 people out of 101 patients. All of them were in the group of patients with intermediate risk. Multiorgan involvement was seen in 7 of 101 patients (LR:2, IR:5). The mean serum level of thyroglobulin (Tg) in cases of distant metastasis was 2.61±8.57 in the low risk group and 17.45±65.21 in the intermediate risk group, and these values showed statistically significant differences (p<0.001). Conclusion: The results of the present study showed that the prevalence of distant metastases in whole-body scan after iodine therapy was seen in approximately 10% of patients. Serum thyroglobulin level can also be used as a clinical marker for early diagnosis of distant metastasis.