An update on radiation absorbed dose to patients from diagnostic nuclear medicine procedures in Tehran: A study on four academic centers.

PURPOSE: Use of radiopharmaceuticals for diagnostic nuclear medicine procedures is one of the main sources of radiation exposure. We performed this study with respect to the rapid growth in nuclear medicine in Iran and lack of updated statistics. MATERIALS AND METHODS: The data were obtained for all active Nuclear Medicine Centers affiliated to Shahid Beheshti University of Medical Sciences during 2009 and 2010. RESULTS: The most frequently performed procedures were bone (30.16%), cardiac (28.96%), renal (17.97%), and thyroid (7.93%) scans. There was a significant decrease in the number of thyroid scintigraphies with (131)I and (99m)Tc-sulfur colloid liver/spleen scans and tremendous increase in the frequencies of cardiac and bone scintigraphies compared to one decade ago. CONCLUSION: Compared to previous studies, there were striking changes in trends of diagnostic nuclear medicine procedures in Tehran. This field is still evolving in the country, and this trend will further change with the introduction of positron emission tomography scanners in future.

Pathological evaluation of differentiated thyroid cancer in patients with positive serum thyroglobulin and negative iodine scan.

OBJECTIVE: There is no investigation that emphasizes the pathology of DTC (differentiated thyroid cancer) patients with positive Tg and negative iodine scan. The present study was performed to assess the pathology of these patients. MATERIALS AND METHODS: In this retrospective study, the records of 500 patients with differentiated thyroid cancer between June 2005 and November 2011 were assessed, and those patients who had elevated serum thyroglobulin (Tg) with a negative whole body I-131 scan (Tg+/WBS-) were included in the study. Patients were followed for clinical and pathological findings of thyroid cancer, including type, variant, local invasion and cervical lymph node metastasis, and serum Tg, TgAb, and TSH levels. RESULTS: A total of 38 patients, including 31 (81.6%) females and 7 (18.4) males with a mean age of 44.2 ± 15.6 years (range, 14 to 77 yrs) took part in the study. All 38 patients had the papillary type of differentiated thyroid cancer (PCDTC), and none had the follicular type of differentiated thyroid cancer (FCDTC). For the variant type of PTC in 16 patients, it was found that 7 were classic type (43.8%), 7 were follicular type (43.8%), and 2 were tall cell (12.4%) for papillary thyroid cancer. In 22 patients no distinct variant had been reported. CONCLUSIONS: This report demonstrated that all of the 38 patients were PTC (100%), which is different from other previous studies. It may be concluded that the overall pathologic subtypes changes of DTC could mainly be due to the iodine fortification program in various geographic regions. The relationship between DTC pathologic subtypes and frequency of Tg+/WBS- condition was difficult to assess in this work. Therefore, further studies are required to evaluate this issue.

Management of gastrointestinal complaints in differentiated thyroid cancer patients treated with (131)I: comparison of the efficacy of pantoprazole, metoclopramide, and ondansetron - a randomized clinical trial.

OBJECTIVE: To compare safety and efficacy of pantoprazol , metoclopramide, ondansetron, as compared to placebo, in controlling gastrointestinal (GI) complaints of thyroid cancer patients treated with I-131these patients. DESIGN: Four-armed, parallel group, single blind, randomized controlled clinical trial, setting: A university hospital, registration: database for clinical trials IRCT2013061713705N1. PATIENTS: 85 patients with differentiated thyroid cancer who received 131I. MAIN OUTCOME MEASURES: Postradioiodine nausea and vomiting within three days of therapy (primary endpoint); occurrence of adverse reaction. RESULTS: The patients' characteristics were similar within the study groups. Among the study variables, age, sex, administered dosage, history of previous GI complaints, and history of hyperemesis gravidarum in female patients were not statistically different among the groups (p > 0.05). The results revealed that only ondansetron shows a therapeutic benefit over the placebo in controlling nausea (p < 0.05); however, it does not prevent vomiting (p > 0.05). The other two drugs, pantoprazole and metoclopramide, did not control nausea (p > 0.05) or vomiting (p > 0.05). CONCLUSIONS: This study may demonstrate that the therapeutic dose of ondansetron could be an effective prophylactic agent in controlling GI complaints in differential thyroid carcinoma (DTC) patients following RAI therapy; however, these preliminary findings should be validated in larger studies.

Differentiated thyroid carcinoma: comparison of histopathologic characteristics, clinical course, and outcome between young children and adolescents.

Differentiated thyroid carcinoma is rare in patients younger than 21 years, especially in children, but it is associated with a greater risk of metastases and recurrence. The aim of our study was to compare the characteristics, clinical course, and outcome of the disease between young children (≤16 years) and adolescents (17-21 years). We reviewed the medical records of 62 young children and adolescents (47 females, 15 males, ≤21 years) with DTC who were diagnosed between 1990 and 2010 and admitted for radioiodine therapy, and compared the histopathologic features, amount and session(s) of radioiodine administration, and outcome in both groups. Young children presented with larger tumor size, more aggressive pathological features, higher incidence of locoregional and distant metastasis, and needed more admissions, and higher amounts of radioiodine for treatment. While there were more disease-free patients at the end of follow-up in the adolescents, the number of patients with stable or progressive disease was higher in younger group. Based on the results of our study, we support the more aggressive approach to DTC treatment in young children, including total thyroidectomy along with more extensive cervical lymph node dissection, L-T4 therapy in suppressive doses, and multiple sessions of postsurgical radioiodine therapy as necessitated.

The role of 99mTc-MIBI scintigraphy in the management of patients with pulmonary tuberculosis.

BACKGROUND: This study aimed to determine whether 99mTc-methoxyisobutylisonitrile (MIBI) scanning could improve diagnostic accuracy of pulmonary tuberculosis (PTB) and help clinical decision making for an accurate management. MATERIAL AND METHODS: 99mTc-MIBI scintigraphy was performed in 62 cases of PTB 34 cases had active pulmonary tuberculosis (APTB) and were at the beginning of antituberculosis medication (group 1) as well as 28 cases had inactive pulmonary tuberculosis (IPTB) and were post antituberculosis medication (group 2). The qualitative and semiquantitative findings of both scanning methods were assessed. For semiquantitative evaluation, regions of interest (ROIs) were drawn over the lesion (L), non-lesion (NL) and neck soft tissue (NST). The mean count values of ROIs were obtained and L/NL and L/NST were calculated. RESULTS: Thirty-four patients with APTB (15 males and 19 females; mean age of 47.85 +/- 1.91 yrs) and 28 cases with IPTB (9 male and 19 females; mean age of 53.96 +/- 2.33 yrs) were included in this study. The sensitivity, specificity, accuracy, positive and negative predictive (PPV and NPV) values of 99mTc-MIBI were 88.2%, 75%, 82.2%, 81.1% and 84% respectively. The mean value of L/NL in the APTB for 99mTc-MIBI was 1.45 +/- 0.18 and L/NST was 1.57 +/- 0.26 which was significant statistically (p < 0.00). CONCLUSIONS: The study demonstrated that 99mTc-MIBI scanning can be complementary to other diagnostic techniques especially in patients with indeterminate APTB and those in whom recurrent disease is suspected. In addition, because of its availability, rather low costs, easy performance, and objective semiquantitative information supplied, 99mTc-MIBI scanning might be establish in routine imaging center to assess the pulmonary tuberculosis. However, further exploration is needed to validate its clinical role.