Radiolabeling, quality control and kit formulation of a new Tc-99m-labeled antibiotic: Tc-99m-doxycycline hyclate

WOS: 000327248400021Since radiolabeled antibiotics specifically bind to the bacterial components they are promising radiopharmaceuticals for the precise diagnosis and detection of infectious lesions. Doxycycline hyclate (DOX) was chosen to investigate as a new radiolabeled antibacterial agent since its bacteriostatic activity against a wide variety of microorganisms. The aim of the present study is to develop simple and easy formulation of DOX with Tc-99m ready to use kit. Tc-99m-DOX was developed and standardized under varying conditions of reducing and antioxidant agent concentration, pH, radioactivity dose and reducing agent type. Labeling studies were performed by changing the selected parameters one by one and optimum labeling conditions were determined. After observing the conditions for maximum labeling efficiency and stability, lyophilized freeze dry kits were prepared accordingly. Radiochemical purity was determined with RTLC and RHPLC which was found more than > 95 %. Two different freeze dry kits were formulated with optimum labeling conditions. The improved kits were found stable up to 6 months.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [Tubitak-110 S 229]; T.R. Prime Ministry State Planning Organization Foundation Grant ProjectPrime Ministry Turkey [09DPT001]This study was supported by The Scientific and Technological Research Council of Turkey (Tubitak-110 S 229). The authors would like to acknowledge the support of T.R. Prime Ministry State Planning Organization Foundation Grant Project Number: 09DPT001 for TLC Scanner. Also the authors thank to Ege University Nuclear Medicine Department technicians for their technical assistance for the animal experiments

Recurrence Rate of Tumor and the Value of Diagnostic I-131 Whole Body Scintigraphy and Recombinant TSH in Low-Risk Well Differentiated Thyroid Cancer Patients Who Have Had I-131 Radioablation

WOS: 000314145000028Objective: The aim of this study was to find out the recurrence rate and to evaluate effectiveness of diagnostic I-131 whole body scintigraphy (WBS) and recombinant human (rh) TSH in low-risk well differentiated thyroid cancer (WDTC) patients who have had I-131 radioablation and have undetectable stimulated serum thyroglobulin (T-g) levels. Material and Methods: Study groups consisted of 149 patients (Group 1) using endogenous TSH stimulation and 50 patients (Group 2) using rhTSH. Mean follow-up period was 12 years for Group 1. Postablative 6th, 18th month, 5th, 10th and 15th year endogenous TSH stimulated diagnostic WBS and serum Tg levels in G1; and 6th month endogenous TSH stimulated and 18th month rhTSH stimulated diagnostic WBS and serum Tg levels in G2 patients were evaluated. Results: The TSH stimulated Tg values were = 30 mu IU/mL in all patients. There was no significant difference between 6th month endogenous TSH and 18th month rhTSH stimulated Tg levels and diagnostic WBS in G2 patients and the 6th, 18th month, 5, 10th and 15th year endogenous TSH stimulated diagnostic WBS and Tg levels in G1 Patients. Conclusion: In low-risk WDTC patients who have undergone total thyroidectomy and I-131 radioablation, the recurrence rate of tumor was extremely low. rhTSH was used successfully without hypothyroid state at I-131 WBS and serum Tg measurement. If 6th month WBS was negative and serum Tg level was undetectable, the 18th month, 5th, 10th and 15th years WBSs were also negative in all patients and yielded no additional information that could influence the following therapeutic strategy and therefore may be avoided. In the follow-up of this group of patients, rhTSH stimulated Tg measurement may be considered as an alternative approach

Significance of First Thyroglobulin Level at the Time of Remnant Ablation in Predicting Clinical Course in Patients with Differentiated Thyroid Carcinoma

WOS: 000326456200003Objectives: To review the significance of first thyroglobulin (Tg) values at the time of remnant ablation, in assessing the clinical course in patients with differentiated thyroid cancer (DTC) Design: Retrospective study Setting: Faculty of Medicine, Ege University, Turkey Subjects: A total of 474 patients with DTC excluding those with positive thyroglobulin auto-antibodies and extra-cervical metastases Intervention: Thyroidectomy followed by radioiodine ablation Main outcome measures: Thyroglobulin, remission rate and clinical course Results: The initial Tg levels at the time of ablation were classified as 30 ng/ml (Group 4). The distribution of the patients was; Group 1: 216 (45.5%), Group 2: 126 (26.5%), Group 3: 81 (17.1%), Group 4: 51 (10.7%). Clinical outcome was categorized as: 1) complete remission, 2) Tg (+ve) and whole body iodine scan (-ve) and 3) cervical metastases. The highest remission rate (99.1 - 92.6 %) was achieved in groups 1, 2 and 3. The clinical course was found to be significantly related with the first Tg levels (Chi-Square test, chi(2), df = 6 p = 0.0001). The PPV and NPV of serum Tg > 30 ng/ml and 30 ng/ml

Concomitant Hyperthyroidism in Patients With Thyroid Carcinoma and the Effects of Iodine Supplementation in an Iodine-Deficient Area

WOS: 000260487000008PubMed ID: 18936609Objectives of this study were to investigate the occurrence and aggressiveness of differentiated thyroid carcinoma (DTC) in patients with hyperthyroidism and to explore the influence of the changes in dietary iodine intake on the association of hyperthyroidism and DTC. Clinical records of 1800 patients with DTC were reviewed. The characteristics of DTC cases with and without thyrotoxicosis and their thyroid tumors were comparatively assessed. In the current series, 76 patients (4.2%) presented with hyperthyroidism before thyroid surgery. The most common type of goiter among 76 patients was toxic multinodular goiter. Presence of lymph node metastasis and recurrence was only observed in patients with toxic diffuse goiter. When DTC cases with and without thyrotoxicosis were compared irrespective of the type of goiter, aggressiveness of thyroid carcinoma was not higher in the thyrotoxic group. Hyperthyroidism, and thyroid carcinoma coexisted in 3.3% and 4.7% in cases diagnosed before and after national iodine supplementation program, respectively (P = 0.04). Clinical course of the disease was not different in the diagnosis of these cases. As a result of no significant difference in complete remission ratio, we conclude that there is no need for a different DTC treatment protocol in cases with coexisting hyperthyroidism

Tc-99m-Doxycycline hyclate: a new radiolabeled antibiotic for bacterial infection imaging

PubMed ID: 24259028WOS: 000331068400005Radiolabeled antibiotics are promising radiopharmaceuticals for the precise diagnosis and detection of infectious lesions. Doxycycline Hyclate (DOX) was chosen to investigate new Tc-99m-labeled antibacterial agent. Ready to use freeze dry kits were formulated with optimum labeling conditions. Human serum stability, sterility, and pyrogenicity of kits were estimated, and gamma scintigraphy, in vivo biodistribution, and histopathological studies with bacterial infected rats were performed. DOX were successfully labeled by Tc-99m with high radiochemical purity, and the labeled compound was stable in human serum. Kits were sterile, pyrogen-free, and stable up to 6months. Static images depicted rapid distribution throughout the body and high uptake in bacterial infected thigh muscle. The uptake ratios of radiopharmaceuticals in infected thigh muscle were found above 2 up to 5h. Five hours after injection, the rats were sacrificed, and biodistribution was determined. Samples of bacterial infected muscle, healthy muscle, blood, liver, spleen, lung, kidney, stomach, intestine, urine and heart were weighed, and the radioactivity was measured by using a gamma counter. The %ID/g of Tc-99m-DOX was found 0.230.06 for infected thigh muscle. According to the imaging, biodistribution, and histopathological studies, the promising characteristics of Tc-99m-DOX make the new radiopharmaceutical valuable to examine for future studies. Copyright (c) 2013 John Wiley ; Sons, Ltd.This study was supported by The Scientific and Technological Research Council of Turkey (Tubitak-110 S 229). The authors would like to acknowledge the support of T.R. Prime Ministry State Planning Organization Foundation Grant Project Number: 09DPT001 for TLC Scanner. Also, the authors thanks Ege University Nuclear Medicine Department for their assistance for the experiments.Scientific and Technological Research Council of Turkey (Tubitak)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110 S 229]; T.R. Prime Ministry State Planning Organization Foundation Grant ProjectPrime Ministry Turkey [09DPT001

Evaluation of Tc-99m-amoxicillin sodium as an infection imaging agent in bacterially infected and sterile inflamed rats

WOS: 000378410000026Bacterial infection is one of the major causes of morbidity and mortality especially in developing countries. The aim of this study was to develop a new radiopharmaceutical for imaging infection. The labeling conditions were optimized, and lyophilized kits were developed for instant preparing. The stability of Tc-99m-AMOX in human serum was identified, sterility and pyrogenicity of the radiopharmaceutical were estimated, gamma scintigraphy and in vivo biodistribution with infected rats were investigated. The promising properties of Tc-99m-AMOX combined with the development of reliable and instant lyophilized kit afford the opportunity of inflammatory process imaging.Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [Tubitak-110 S 229]; T.R. Prime Ministry State Planning Organization FoundationTurkiye Cumhuriyeti Kalkinma Bakanligi [09DPT001]This study was supported by The Scientific and Technological Research Council of Turkey (Tubitak-110 S 229). The authors would like to acknowledge the support of T.R. Prime Ministry State Planning Organization Foundation Grant Project Number: 09DPT001 for TLC Scanner. Also the authors thank to Ege University Nuclear Medicine Department technicians for their technical assistance for the animal experiments