Prasanta Pradhan

Functional expression of sodium iodide symporter (NIS) in human breast cancer tissue.

Sodium iodide symporter (NIS) is a molecule involved in active accumulation of iodine in thyroid gland for the biosynthesis of thyroid hormone. Its expression has also been demonstrated in extra-thyroidal tissues including lactating mice mammary gland and also in human breast cancers. Iodide transport in thyroid cells through NIS is the basis for using radioiodine for diagnosis and treatment of differentiated thyroid carcinoma. The similar approach may prove beneficial for the diagnosis and treatment of breast cancer if iodine uptake, its retention and NIS expression can be shown unequivocally in malignant tumors. The aim of the present study was to investigate NIS expression, in vivo iodine transport ability and fate of iodine in human breast tumors. Women (age 33–58 years) with infiltrating duct carcinoma confirmed by FNAC and subsequent histopathology were the subject of this study. Expression of NIS RNA and protein was confirmed by RNAase protection assay, western blot and immunohistochemistry respectively in surgically excised breast tumor tissue. Iodine transport ability and its nature was assessed both in vivo and in vitro. We report high NIS expression at both transcriptional and translational level and its ability to transport iodine in human breast tumors. The in vivo iodine transport ability was confirmed by scintigraphy. Unlike thyroid, perchlorate and thiocyanate do not inhibit iodine transport in breast tumors. The presence of iodinated proteins suggests the longer retention time. The unequivocal demonstration of NIS expression, its functionality and retention of iodine by organification further provides supportive evidence for use of radioiodine as an additional treatment modality of human breast carcinoma.

Standardization of Administered Activities in Pediatric Nuclear Medicine: A Report of the First Nuclear Medicine Global Initiative Project, Part 1—Statement of the Issue and a Review of Available Resources

The Nuclear Medicine Global Initiative (NMGI) was formed in 2012 and consists of 13 international organizations with direct involvement in nuclear medicine. The underlying objectives of the NMGI were to promote human health by advancing the field of nuclear medicine and molecular imaging, encourage global collaboration in education, and harmonize procedure guidelines and other policies that ultimately lead to improvements in quality and safety in the field throughout the world. For its first project, the NMGI decided to consider the issues involved in the standardization of administered activities in pediatric nuclear medicine. This article presents part 1 of the final report of this initial project of the NMGI. It provides a review of the value of pediatric nuclear medicine, the current understanding of the carcinogenic risk of radiation as it pertains to the administration of radiopharmaceuticals in children, and the application of dosimetric models in children. A listing of pertinent educational and reference resources available in print and online is also provided. The forthcoming part 2 report will discuss current standards for administered activities in children and adolescents that have been developed by various organizations and an evaluation of the current practice of pediatric nuclear medicine specifically with regard to administered activities as determined by an international survey of nuclear medicine clinics and centers. Lastly, the part 2 report will recommend a path forward toward global standardization of the administration of radiopharmaceuticals in children.

Standardization of Administered Activities in Pediatric Nuclear Medicine: A Report of the First Nuclear Medicine Global Initiative Project, Part 2—Current Standards and the Path Toward Global Standardization

The Nuclear Medicine Global Initiative (NMGI) was formed in 2012 and consists of 13 international organizations with direct involvement in nuclear medicine. The underlying objectives of the NMGI are to promote human health by advancing the field of nuclear medicine and molecular imaging, encourage global collaboration in education, and harmonize procedure guidelines and other policies that ultimately lead to improvements in quality and safety in the field throughout the world. For its first project, the NMGI decided to consider the issues involved in the standardization of administered activities in pediatric nuclear medicine. It was decided to divide the final report of this project into 2 parts. Part 1 was published in this journal in the spring of 2015. This article presents part 2 of the final report. It discusses current standards for administered activities in children and adolescents that have been developed by various professional organizations. It also presents an evaluation of the current practice of pediatric nuclear medicine specifically with regard to administered activities as determined by an international survey of 313 nuclear medicine clinics and centers from 29 countries. Lastly, it provides recommendations for a path toward global standardization of the administration of radiopharmaceuticals in children.

Preoperative contrast-enhanced computerized tomography should not delay radioiodine ablation in differentiated thyroid carcinoma patients.

BACKGROUND There is concern about potential interference of iodinated contrast used in contrast-enhanced computerized tomography (CECT) with radioiodine therapy in differentiated thyroid carcinoma (DTC). The aim of this study was to determine the effect of iodinated contrast on urinary iodine concentration (UIC) in patients having thyroidectomy compared with control groups without CECT and without thyroidectomy. METHODS This prospective control study consisted of 4 groups each comprising 32 patients. Group 1- DTC patients undergoing preoperative CECT, group 2- DTC patients not undergoing CECT, group 3- benign goiter patients undergoing preoperative CECT, and group 4- patients with non-thyroidal diseases undergoing preoperative CECT. Spot UIC before CECT, after surgery (5-7 d), and at follow-up (4-6 wk) were compared among the groups. RESULTS The median basal UIC levels were not significantly different between the four groups (232.2 versus 263.9 versus 268.2 versus 178.2 μg/L, respectively, P = 0.443). In contrast, groups having preoperative CECT had significantly higher UIC levels at discharge (924 versus 329 versus 776 versus 661 μg/L, respectively, P = 0.001). These differences became insignificant at follow-up (225 versus 252 versus 310 versus 275 μg/L, respectively, P = 0.505). Patients having follow-up UIC values above the conventional cut-off of clinically relevant iodine excess (>200 μg/L) also had significantly higher basal values than those having lower follow-up values (283.0 versus 181.7 μg/L; P = 0.037). CONCLUSIONS Irrespective of the fact whether a patient is thyroidectomized or not preoperative CECT using non-lipophilic contrast does not result in long-term iodine retention.

Left ventricular remodeling after late revascularization correlates with baseline viability.

The ideal management of stable patients who present late after acute ST-elevation myocardial infarction (STEMI) is still a matter of conjecture. We hypothesized that the extent of improvement in left ventricular function after successful revascularization in this subset was related to the magnitude of viability in the infarct-related artery territory. However, few studies correlate the improvement of left ventricular function with the magnitude of residual viability in patients who undergo percutaneous coronary intervention in this setting. In 68 patients who presented later than 24 hours after a confirmed first STEMI, we performed resting, nitroglycerin-enhanced, technetium-99m sestamibi single-photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) before percutaneous coronary intervention, and again 6 months afterwards. Patients whose baseline viable myocardium in the infarct-related artery territory was more than 50%, 20% to 50%, and less than 20% were divided into Groups 1, 2, and 3 (mildly, moderately, and severely reduced viability, respectively). At follow-up, there was significant improvement in end-diastolic volume, end-systolic volume, and left ventricular ejection fraction in Groups 1 and 2, but not in Group 3. We conclude that even late revascularization of the infarct-related artery yields significant improvement in left ventricular remodeling. In patients with more than 20% viable myocardium in the infarct-related artery territory, the extent of improvement in left ventricular function depends upon the amount of viable myocardium present. The SPECT-MPI can be used as a guide for choosing patients for revascularization.

Comparative evaluation of Tc-99m cystine and Tc-99m MAG3 in normals and patients with renal functional impairment.

Tc-99m cystine has been proved to be a good renal agent in animals for morphologic as well as the functional status of the kidney. In this study, we compared Tc-99m cystine with Tc-99m mercaptoacetyltriglycine, which is used for evaluation of renal function in normal patients, and those with various degrees of renal functional impairment. The clearance values and static images are compared with Tc-99m mercaptoacetyltriglycine. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Overt Skeletal Metastases in a Patient of Occult (Microscopic) Follicular Thyroid Carcinoma: a Rare Case

Occult follicular thyroid carcinoma (FTC) presenting as distant metastases is a rare occurrence. However, despite being occult in majority of these cases, primary tumor can be detected on thyroid imaging or during surgery. Here, we present an extremely rare case of an occult FTC with overt skeletal metastases in which primary tumor was discernible only on microscopic examination.

Role of PET in Coronary Artery Disease

The use of positron-emitting radionuclides, especially 18 F labeled fluorodeoxy glucose (18 F-FDG), has increased recently due to its role in oncology. This has paved the way to look for other uses for these agents. The use of positron emission tomography (PET) as a noninvasive tool for imaging the heart in coronary artery disease to look for perfusion defects and viability has already been established. This has helped us to know the extent of myocardial blood flow, the metabolic changes occurring in the myocardium, and changes in the cardiac autonomic innervations in various pathological conditions.