Tc-99m Pertechnetate Research Articles

Sentinel lymph node scintigraphy in cutaneous melanoma using a planar calibration phantom filled with Tc-99m pertechnetate solution for body contouring.

Background and aimsMelanoma is a disease that has an increasing incidence worldwide. Sentinel lymph node scintigraphy is a diagnostic tool that offers important information regarding the localization of the sentinel lymph nodes offering important input data to establish a pertinent and personalized therapeutic strategy. The golden standard in body contouring for sentinel lymph node scintigraphy is to use a planar flood source of Cobalt-57 (Co-57) placed behind the patients, against the gamma camera. The purpose of the study was to determine the performance of the procedure using a flood calibration planar phantom filled with aqueous solution of Technetion-99m (Tc-99m) in comparison with the published data in literature where the gold standard was used.MethodsThe study was conducted in the Department of Nuclear Medicine of Oncology Institute “Prof. Dr. Ion Chiricuţă” Cluj-Napoca in 95 patients, 31 males and 64 females. The localization of the lesions was grouped by anatomical regions as follows: 23 on lower limbs, 17 on upper limbs, 45 on thorax and 10 on abdomen. The calibration flood phantom containing aqueous solution of Tc-99m pertechnetate was used as planar source to visualize the body contour of the patients for a proper anatomic localization of detected sentinel lymph nodes. The radiopharmaceutical uptake in sentinel lymph nodes has been recorded in serial images following peritumoral injection of 1 ml solution of Tc-99m albumin nanocolloids with an activity of 1 mCi (37 MBq). The used protocol consisted in early acquired planar images within 15 minutes post-injection and delayed images at 2–3 hours and when necessary, additional images at 6–7 hours. The acquisition matrix used was 128×128 pixels for an acquisition time of 5 – 7 minutes. The skin projection of the sentinel lymph nodes was marked on the skin and surgical removal of detected sentinel lymph nodes was performed the next day using a gamma probe for detection and measurements.ResultsThe sentinel lymph nodes were detected in 92 cases and confirmed with the gamma probe during the surgical procedure. The localization of the lymph nodes was as follows: for the tumors localized on lower limb 23 lymph nodes were localized in inguinal region, for the tumors localized on upper limb, 17 lymph nodes were localized in axilla, for the tumors localized on the thorax, 40 lymph nodes were localized in axilla and 3 were localized in the inguinal region; for the tumors localized on the abdomen, 1 lymph node was localized in axilla and 8 lymph nodes was localized in inguinal region. Regarding the negative sentinel lymph node cases, 2 cases were registered for primarily lesions localized on thorax and 1 for a lesion localized on abdomen. According to histology, 26 cases revealed lymphatic metastatic invasion. Dose rates measured at 1m from the calibrator phantom had an average value of 3.46 μSv/h (SD 0.19) and at 1.4m, the value was 2.57 μSv/h (SD 0.22). Dose rates measured at the same distances from the Co-57 planar flood source had a average values of 32.5μSv/h (SD 0.11) respectively 24.1 μSv/h (SD 0.14).ConclusionThe planar calibration flood phantom is an effective tool for body contouring in sentinel lymph node scintigraphy and offers accurate anatomical information to efficiently localize the detected sentinel lymph nodes in melanoma, being for the first time used and mentioned as a pertinent alternative in our department.

The Incidence of Hypothyroidism Following the Radioactive Iodine Treatment of Graves' Disease and the Predictive Factors Influencing its Development.

The purpose of this study is to evaluate and compare the incidence of hypothyroidism following different fixed radioactive iodine-131 (131I) activities in the treatment of Graves’ disease (GD) and to investigate the predictive factors that may influence its occurrence. This retrospective analysis was performed on 272 patients with GD who were treated with 131I, among whom 125 received 370 MBq and 147 received 555 MBq. The outcome was categorized as hypothyroidism, euthyroidism, and persistent hyperthyroidism. Multiple logistic regression analysis was performed to identify significant risk factors that affect the development of hypothyroidism. The incidence of hypothyroidism following the first low activity was 24.8% with a high treatment failure rate of 58.4%, compared with 48.3% and 32% following high activity. The overall cumulative incidence of hypothyroidism following repeated activities was 50.7%, out of which 73.9% occurred after the first activity and 20.3% after the second activity. The higher 131I activity (P < 0.001) and average and mild enlargement of the thyroid gland (P = 0.004) were identified as significant independent factors that increase the rate of incidence of hypothyroidism (Odds ratios were 2.95 and 2.59). No correlation was found between the development of hypothyroidism and the factors such as age, gender, presence of exophthalmos, previous antithyroid medications, and the durations, and Technetium-99m (Tc-99m) pertechnetate thyroid uptake. In view of the high treatment failure rate after first low activity and lower post high activity hypothyroid incidence, high activity is recommended for GD patients, reserving the use of 370MBq for patients with average sized and mildly enlarged goiter; this increases patient convenience by avoiding multiple activities to achieve cure and long-term follow-up.

A Rare Presentation of Autonomously Functioning Papillary Thyroid Cancer: Malignancy in Marine-Lenhart Syndrome Nodule.

Objective. Marine-Lenhart Syndrome (MLS) is defined as concomitant occurrence of autonomously functioning thyroid nodule (AFTN) with Graves' disease (GD). Malignancy in a functional nodule is rare. We aimed to present an extremely rare case of papillary thyroid cancer in a MLS nodule with lateral lymph node metastases. Case. A 43-year-old male presented with hyperthyroidism and Graves' ophthalmopathy. On Tc99m pertechnetate scintigraphy, a hyperactive nodule in the left upper thyroid pole was detected and the remaining tissue showed a mildly increased uptake. The ultrasonography demonstrated 15.5 × 13.5 × 12 mm sized hypoechoic nodule in the left upper pole of the thyroid and round lymph nodes on the left side of the neck. Fine needle aspiration biopsy (FNAB) of the nodule and lymph node revealed cytological findings consistent with papillary cancer. Total thyroidectomy with central and left modified radical neck dissection was performed. On pathologic examination, two foci of micropapillary cancer were detected. The skip metastases were present in three lymph nodes on the neck. Conclusion. AFTN can be seen rarely in association with GD. It is not possible to exclude malignancy due to the clinical and imaging findings. In the presence of suspicious clinical and sonographic features, FNAB should be performed.

Colloid goitre in submental ectopic thyroid: a rare entity posing a diagnostic and therapeutic challenge

Ectopic thyroid is a rare entity in clinical practice. It results from defects at early stages of thyroid gland embryogenesis, during its passage from the base of the tongue to its final pre-tracheal position, anterolateral to second, third, and fourth tracheal rings. It is usually found along the course of the thyroglossal duct or laterally in the neck, also in distant places such as the mediastinum or very rarely in the sub-diaphragmatic organs. In our case, an 18-year old girl presented with a sub-mental swelling. There are various differentials for such swelling. A careful history, scrupulous clinical examination and investigations comprising ultrasonography of neck, MRI scan, Tc-99m pertechnetate thyroid scan and Fine needle aspiration cytology (FNAC) from the swelling revealed that it was a case of colloid goitre in the ectopic sub-mental thyroid and there was no thyroid tissue in its normal anatomic location. We initially treated the patient with supplemental levothyroxine trial for 6-months followed by surgical excision. We report this case as it is a rare phenomenon and also because diagnostic and therapeutic dilemma exists in its management.

Sealing efficacy of system B versus Thermafil and Guttacore obturation techniques evidenced by scintigraphic analysis

BackgroundThis study compared root canal sealing ability, filled by Continuous Wave compaction and two carrier-based obturation systems, using the nuclear medicine approach.Material and MethodsFifty-five single-rooted extracted teeth were selected. The crowns were sectioned and each tooth was instrumented using rotary Protaper® Universal system. The roots were divided into 3 experimental groups and two control groups. Forty-five root canals were filled, using Continuous Wave, GuttaCore or Thermafil system and TopSeal sealer. Ten teeth were used as control. On the 7th days the apices were submersed in a solution of sodium pertechnetate 99mTc for 3 hours and the radioactivity was counted.ResultsAlthough apical leakage in the Continuous Wave group was lower compared with GuttaCore and Thermafil groups, there was no statistical difference (p>0.05).ConclusionsSystem B, GuttaCore and Thermafil techniques showed a similar sealing effect. Key words:Continuous wave compaction, Gutta percha core-carrier, leakage, nuclear medicine.

Cutoff value of thyroid uptake of (99m)Tc-pertechnetate to discriminate between Graves' disease and painless thyroiditis: a single center retrospective study.

Thyroid uptake of (99m)Tc-pertechnetate is a useful way to determine the cause of thyrotoxicosis. In daily clinical practice, (99m)Tc-pertechnetate uptake is used to discriminate between Graves' disease and painless thyroiditis when clinical information is not enough to make the distinction. However, since the optimal cutoff value of (99m)Tc-pertechnetate uptake has not yet been elucidated, our aim was to determine this value. We recruited patients with thyrotoxicosis in whom (99m)Tc-pertechnetate uptake was measured in clinical settings between 2009 and 2013. Three experienced endocrinologists (who were blinded to the value of (99m)Tc-pertechnetate uptake and initial treatment) diagnosed the cause of thyrotoxicosis based on thyrotropin, free triiodothyronine, free thyroxine, and thyrotropin receptor antibody levels, and by ultrasound findings and using images of thyroid uptake of (99m)Tc-pertechnetate without the actual values. Ninety-four patients diagnosed as having Graves' disease or painless thyroiditis were finally included. According to the diagnosis, the optimal cutoff value of (99m)Tc-pertechnetate uptake was determined by receiver operating characteristics analysis. A cutoff value of 1.0% provided optimal sensitivity and specificity of 96.6% and 97.1%, respectively. Then, its validity was confirmed in 78 patients with confirmed Graves' disease or painless thyroiditis diagnosed at another institute. Applying this cutoff value to the patients with thyrotoxicosis revealed positive and negative predictive values for Graves' disease of 100% and 88.9%, respectively. In conclusion, a cutoff value for (99m)Tc-pertechnetate uptake of 1.0% was useful to discriminate between Graves' disease and painless thyroiditis.

Role of Tc-99m pertechnetate for remnant scintigraphy, post-thyroidectomy, and serum thyroglobulin and antithyroglobulin antibody levels in the patients with differentiated thyroid cancer.

Postoperative scanning may help to identify patients with differentiated thyroid cancer (DTC); however, low dose I-131 can lead to stunning and suboptimal response to ablative therapy. The aim of this retrospective study is to compare postablative I-131 scintigraphy with post-thyroidectomy Tc-99m pertechnetate scintigraphy, serum thyroglobulin (Tg) and antithyroglobulin antibody (TgAb) levels in patients with DTC. Patients who had undergone surgical thyroidectomy for DTC were evaluated retrospectively. All patients had undergone Tc-99m pertechnetate and postablative I-131 scans. Serum Tg and TgAb levels were measured in all subjects. Preablative pertechnetate scans of the thyroid bed were viewed blindly and then directly compared with postablative I-131 scans and Tc-99m pertechnetate scintigraphy was compared with serum Tg and TgAb levels. One hundred and seventy-four patients (146 women, 28 men) with a mean age of 48.7 ± 13.1 (range 12-84) years who had undergone surgical thyroidectomy for DTC were evaluated retrospectively. Of 174 patients, 6 (3%) had negative I-131 and also Tc-99m pertechnetate scintigraphy results. Of the remaining 168 positive I-131 scans, 131 (75%) were positive in at least one site on the pertechnetate scan, 19 (11%) were considered to have equivocal uptake and 18 (11%) were negative. For the per-site analysis, pertechnetate sites were considered to be accurately determined if they showed concordant uptake at sites that correlated precisely with those seen on the postablation I-131 scans. There were a total of 356 positive foci on I-131 scans. Of these, 273 foci (77%) were unequivocally positive on pertechnetate scintigraphy, 41 (11%) showed equivocal uptake and 42 (12%) foci could not be detected. There were statistically significant differences (p < 0.0001) between the negative and positive foci in terms of Tg levels on pertechnetate sites. A positive pertechnetate scan is, therefore, sufficient to guide progression to I-131 ablation in most patients. Pertechnetate scintigraphy may be of particular benefit if it is considered desirable to avoid use of I-131 in post-thyroidectomy remnant imaging. Tg level is an important parameter in the detection of remnant thyroid tissue in patients with DTC.

Radioisotopic Purity of Sodium Pertechnetate 99mTc Produced with a Medium-Energy Cyclotron: Implications for Internal Radiation Dose, Image Quality, and Release Specifications.

Cyclotron production of 99mTc is a promising route to supply 99mTc radiopharmaceuticals. Higher 99mTc yields can be obtained with medium-energy cyclotrons in comparison to those dedicated to PET isotope production. To take advantage of this capability, evaluation of the radioisotopic purity of 99mTc produced at medium energy (20-24 MeV) and its impact on image quality and dosimetry was required. Thick 100Mo (99.03% and 99.815%) targets were irradiated with incident energies of 20, 22, and 24 MeV for 2 or 6 h. The targets were processed to recover an effective thickness corresponding to approximately 5-MeV energy loss, and the resulting sodium pertechnetate 99mTc was assayed for chemical, radiochemical, and radionuclidic purity. Radioisotopic content in final formulation was quantified using γ-ray spectrometry. The internal radiation dose for 99mTc-pertechnetate was calculated on the basis of experimentally measured values and biokinetic data in humans. Planar and SPECT imaging were performed using thin capillary and water-filled Jaszczak phantoms. Extracted sodium pertechnetate 99mTc met all provisional quality standards. The formulated solution for injection had a pH of 5.0-5.5, contained greater than 98% of radioactivity in the form of pertechnetate ion, and was stable for at least 24 h after formulation. Radioisotopic purity of 99mTc produced with 99.03% enriched 100Mo was greater than 99.0% decay corrected to the end of bombardment (EOB). The radioisotopic purity of 99mTc produced with 99.815% enriched 100Mo was 99.98% or greater (decay corrected to the EOB). The estimated dose increase relative to 99mTc without any radionuclidic impurities was below 10% for sodium pertechnetate 99mTc produced from 99.03% 100Mo if injected up to 6 h after the EOB. For 99.815% 100Mo, the increase in effective dose was less than 2% at 6 h after the EOB and less than 4% at 15 h after the EOB when the target was irradiated at an incident energy of 24 MeV. Image spatial resolution and contrast with cyclotron-produced 99mTc were equivalent to those obtained with 99mTc eluted from a conventional generator. Clinical-grade sodium pertechnetate 99mTc was produced with a cyclotron at medium energies. Quality control procedures and release specifications were drafted as part of a clinical trial application that received approval from Health Canada. The results of this work are intended to contribute to establishing a regulatory framework for using cyclotron-produced 99mTc in routine clinical practice.

Role and Outcome of RA131 I Therapy in Patients with Autonomous Toxic Adenoma

Radioactive iodine (RAI) therapy is preferred in the treatment of toxic autonomous adenomas because of its effectiveness, noninvasiveness, and low costs(1 ). Among patients with toxic adenomas, radioiodine therapy not only ameliorates hyperthyroidism but also reduces the size of the adenomas(2).Objective: The aim of this retrospective study is to detect the long term effects of this therapy on the thyroid function of patients with toxic adenoma treated in our department. Patients and methods: The study population included 60 cases with autonomous toxic adenoma seen at Nuclear Medicine Unit, Cairo University during the period of January 2004 till December 2010 for RAI-131 therapy. All patients were followed for 4 to 6 years (mean 5, 61 ± 0.53, median 5) following RAI- 131 therapy till December 2014. Clinical examination was done for all patients together with laboratory investigations including TSH level, FT3, FT4 measured by a radioimmunoassay (RIA).Thyroid imaging using 99m-Tc pertechnetate was done and thyroid uptake was estimated for all cases with normal reference range (0.5-4%). Neck U/S for detection of nodule size was also done. RAI dose were given us infixed dose according to nodule size (20-29 mCi).Follow up was done through clinical and laboratory evaluation guided by FT3, FT4, and TSH levels 3, 6 months after treatment then every year to exclude any possible complications. Results:131I therapeutic dose was given to all patients. The studied population was divided into two groups: Group (1): 12 patients (20%) with moderate sized nodule received 20 mCi of I- 131. Group (2): 48 patients (80%) with large sized nodule received 25-29 (mCi). No differences were observed between patients who became hypothyroid and those who became euthyroid after 131I treatment of toxic adenoma, as regards age at the time of treatment, pre 131I medical treatment, 99m-Tc pertechnetate thyroid uptake, size of the adenoma (smaller or larger than 3 cm) or pre 131I TSH levels.. Normal level of TSH is seen in 52 patients (86.7%) in their 1 st follow up visit 6 months after treatment with euthyroid state, while 8 patients (13.3%) had hypothyroidism with TSH level (>5 mIu/L) within 7.82 ±0.58 months. Among the 40 patients (66.6%) had nodules with complete suppression to the rest of thyroid tissue, no patients turned hypothyroid, whereas in the 20 patients (33.6%) who had partial suppression to the rest of thyroid tissue, 8 patients turned hypothyroid, 5 of them received 20 mCi, while the other 3 patients received 25-29 (mCi).Persistence or recurrence thyrotoxicosis was not observed in the studied population.Conclusion, Treatment of toxic adenoma with 131I in the dose of 20-29 mCi is a welltolerated therapy, leading to rapid relief of hyperthyroid symptoms. Hypothyroidism is a late side effect of RAI that needs life-long treatment and regular follow-up once or twice a year; it developed within the first year after 131I administration in 13.3% of the patients, specially those patients with partial suppression.

551. Longitudinal High Resolution 3-D Imaging of AAV Gene Expression In Vivo

Adeno-associated viral (AAV) are small non-integrating vectors that are being developed for a number of gene therapy applications. Different AAV serotypes, armed with constitutive or tissue specific promoters, capable of infecting various tissue types have been engineered to enable preferential transduction of the target tissues. In order to rapidly screen and evaluate the best AAV serotype and promoter for high levels of transgene expression in a specific organ, we have been developing the sodium iodide symporter (NIS) as a reporter gene for screening the biodistribution of AAV vectors. NIS is expressed endogenously in thyroid follicular cells where its role is to concentrate iodine for the synthesis of thyroid hormones. For more than 70 years, thyroidal NIS expression has been provided the basis for I-123 gamma camera or SPECT/CT imaging in thyroid disorders and for I-131 tumor ablation of metastatic thyroid cancer. Using NIS imaging, we would be able to longitudinally monitor gene expression in the same animal over time, from rodents, dogs, nonhuman primates and in human subjects. In this study, we have generated a panel of AAV vectors of serotype 1, 2, 5, 8, and 9 and administered the vectors via various routes of delivery. The mice and rats were imaged using SPECT (I-125 or Tc99m pertechnetate) isotopes on a high resolution microSPECT/CT scanner. Results indicate robust AAV gene expression by 2 weeks post vector administration. View Large Image | Download PowerPoint Slide[Figure 1: AAV mediated NIS gene expression in the liver and heart of mice post IV administration of vector]. For example, AAV9-CMV-NIS gave high levels of cardiac gene expression and interestingly, of subcutaneous brown fat (scapular region). In contrast AAV1-CMV-NIS resulted in highest gene expression in the subcutaneous brown fat only whereas AAV-LST-NIS (liver specific promoter) gave only NIS expression in the liver. When the regions of interests were quantitated, we found that AAV-NIS gene expression was maintained over 90 days in immunocompetent rats and over 200 days in immunocompromised mice. Using NIS as the reporter gene, we are able to use the same vector construct and perform similar noninvasive NIS imaging studies in large animal models using the same SPECT isotopes in combination with clinical SPECT/CT scanners. In contrast to traditional biodistribution studies utilizing PCR analysis or luciferase imaging, NIS imaging enables rapid identification of the organs supporting high levels of transgene expression.

Submandibular Lateral Ectopic Thyroid Tissue: Ultrasonography, Computed Tomography, and Scintigraphic Findings.

Ectopic thyroid can be encountered anywhere between the base of tongue and pretracheal region. The most common form is euthyroid neck mass. Herein, we aimed to present the findings of a female case with ectopic thyroid tissue localized in the left submandibular region. A 44-year-old female patient, who underwent bilateral subtotal thyroidectomy four years ago with the diagnosis of multinodular goiter, was admitted to our hospital due to a mass localized in the left submandibular area that gradually increased in the last six months. Neck ultrasonography, contrast-enhanced computed tomography, and scintigraphic examination were performed on the patient. On thyroid scintigraphy with Tc-99m pertechnetate, thyroid tissue activity uptake showing massive radioactivity was observed in the normal localization of the thyroid gland and in the submandibular localization. The focus in the submandibular region was excised. Pathological examination of the specimen showed normal thyroid follicle cells with no signs of malignancy. The submandibular mass is a rarely encountered lateral ectopic thyroid tissue. Accordingly, ectopic thyroid tissue should also be considered in the differential diagnosis of masses in the submandibular region.

Evaluation of the effect of isotretinoin on salivary gland function by Tc-99m pertechnetate imaging in acne vulgaris patients.

Isotretinoin is an effective drug utilized in the management of acne vulgaris and is known to cause dry mouth. In this study, we aimed to evaluate this effect of isotretinoin on the salivary gland function in patients with acne vulgaris using technetium-99m (Tc-99m) pertechnetate imaging of the salivary glands. The study population consisted of 28 patients with acne vulgaris (6 males and 22 females, mean age 20.2 ± 2.3 years), who were treated with isotretinoin for 6 months. We performed radionuclide imaging of the salivary glands pretreatment and at months 3 and 6 of treatment. After 185 MBq (5 mCi) of Tc-99m pertechnetate was intravenously administered, imaging of the salivary glands was performed over a 25-min period. We measured the following glandular function parameters for the parotid and submandibular salivary glands via time-activity curves: uptake ratio, maximum accumulation, and ejection fraction. Statistically significant differences were observed in the values obtained at months 3 and 6 of treatment, compared with the pretreatment values. This study demonstrated that radionuclide imaging of the salivary glands can clearly show the glandular functions that are affected by drugs such as isotretinoin.

Accurately localizing the thyroid tissue in mature cystic teratoma of ovary by single-photon emission computerized tomography/computerized tomography.

A 30-year-old woman with hyperthyroidism was admitted to hospital. Although increased thyroid function was found, the gland was normal in ultrasonography (USG). Additionally, thyroid iodine uptake and Tc-99m pertechnetate scintigraphy was normal. Abdomen USG detected a cystic pelvic mass in left ovary. A whole-body scan was performed 48 hours after oral ingestion of 29.6 MBq (0.8 mCi) I-131 (iodine-131) revealed a round structure located to the left lower abdomen. Iodine uptake was detected in this cyst which was compatible with functional thyroid tissue demonstrated by SPECT/CT. The patient was underwent surgical operation and histopathology confirmed mature cystic teratoma. Accurate localization and depiction of thyroid tissue in ovary mass was provided with SPECT/CT.

Prediction of the success of thyroid remnant ablation using preablative 99mTc pertechnetate scintigraphy and postablative dual 131I scintigraphy.

The aim of this study was to predict the success of 131I ablation using preablative 99mTc pertechnetate salivary scintigraphy and a postablative dual 131I scan in differentiated thyroid cancer (DTC). A total of 168 DTC patients who underwent 131I ablation with preablative salivary scintigraphy and a postablative dual (early and delayed) 131I scan were enrolled. For salivary scintigraphy, the thyroid remnant uptake was visually assessed. For the dual 131I scan, the thyroid remnant to background uptake ratios (TBRs) on early and delayed scans were measured and the percentage change in TBR (TBRΔ) was calculated. Thyroid remnant uptake was seen in 69 (41%) patients on salivary scintigraphy and in 162 (96%) patients on the dual 131I scan. The success rate of ablation was higher in patients with negative remnant uptake on salivary scintigraphy (86%) than in patients with positive remnant uptake (58%, P=0.0001). The success rate of ablation was 100% in patients with no remnant uptake on both salivary scintigraphy and the dual 131I scan. The success rate of ablation was higher in patients with TBRΔ 0 or more than in patients with TBRΔ less than 0, irrespective of remnant uptake on salivary scintigraphy (91 vs. 70%, P=0.03, for patients without remnant uptake on salivary scintigraphy; 74 vs. 48%, P=0.05, for patients with remnant uptake on salivary scintigraphy). The success of thyroid remnant ablation in DTC can be predicted by the presence of remnant uptake on preablative 99mTc pertechnetate scintigraphy and change in remnant uptake on the postablative dual 131I scan.

Dual ectopic thyroid presenting with an anterior neck mass

A 34-year-old woman presented with a 2-year history of anterior midline neck swelling. The physical examination revealed a soft, mobile, nontender, 2 × 1 cm, anterior midline neck mass. Ultrasonography showed a heterogeneously isoechoic mass (2.23 × 1.18 cm) in the subhyoid region, while a thyroid gland was not seen in the normal position (Fig. 1A). A 99mTc-pertechnetate scan demonstrated two distinct focal areas of radiotracer uptake in the sublingual and subhyoid regions, without uptake in the region of the normal thyroid gland (Fig. 1B). Neck computed tomography (CT) revealed two heterogeneous hyperdense enhancing masses, one in the sublingual region and the other in the subhyoid region (Fig. 1C). The thyroid function tests suggested subclinical hypothyroid status with a T4 level of 4.95 µg/dL (normal range, 4.7 to 12.5) and thyroid stimulating hormone level of 15.26 mIU/L (normal range, 0.17 to 4.65). Anti-microsomal antibody and anti-thyroglobulin antibody were negative. A dual ectopic thyroid was diagnosed based on the radiological findings and replacement therapy with levothyroxine was initiated. Figure 1 (A) Neck ultrasonography shows a heterogeneously isoechoic neck mass in the subhyoid region. (B) 99mTc pertechnetate thyroid scan shows two focal areas of uptake in the sublingual (upper arrow) and subhyoid regions (lower arrow). (C) Sagittal computed ... Ectopic thyroid tissue is an uncommon congenital aberration resulting from abnormal migration of the thyroid gland. The most frequent ectopic positions of thyroid tissue include the lingual, sublingual, and subhyoid areas. It is very rare for two ectopic foci to be present simultaneously. The mean age of the reported cases with a dual ectopic thyroid was 15 years. Most cases are diagnosed when they are younger than 30 years and are euthyroid or mildly hypothyroid. When assessing an anterior neck mass, it is important to differentiate ectopic thyroid tissue from other causes, such as a thyroglossal duct cyst, lipoma, lymph node, epidermoid cyst, and malignancies, to prevent inappropriate excision. Thyroid scintigraphy, along with either neck CT or ultrasonography, should be considered in cases of anterior midline neck swelling.

Microscopic validation of macroscopic in vivo images enabled by same-slide optical and nuclear fusion.

It is currently difficult to determine the molecular and cellular basis for radioscintigraphic signals obtained during macroscopic in vivo imaging. The field is in need of technology that helps bridge the macroscopic and microscopic regimes. To solve this problem, we developed a fiducial marker (FM) simultaneously compatible with 2-color near-infrared (NIR) fluorescence (700 and 800 nm), autoradiography, and conventional hematoxylin-eosin (HE) histology. The FM was constructed from an optimized concentration of commercially available human serum albumin, 700- and 800-nm NIR fluorophores, (99m)Tc-pertechnetate, dimethyl sulfoxide, and glutaraldehyde. Lymphangioleiomyomatosis cells coexpressing the sodium iodide symporter and green fluorescent protein were labeled with 700-nm fluorophore and (99m)Tc-pertechnatate and then administered intratracheally into CD-1 mice. After in vivo SPECT imaging and ex vivo SPECT and NIR fluorescence imaging of the lungs, 30-μm frozen sections were prepared and processed for 800-nm NIR fluorophore costaining, autoradiography, and HE staining on the same slide using the FMs to coregister all datasets. Optimized FMs, composed of 100 μM unlabeled human serum albumin, 1 μM NIR fluorescent human serum albumin, 15% dimethyl sulfoxide, and 3% glutaraldehyde in phosphate-buffered saline (pH 7.4), were prepared within 15 min, displayed homogeneity and stability, and were visible by all imaging modalities, including HE staining. Using these FMs, tissue displaying high signal by SPECT could be dissected and analyzed on the same slide and at the microscopic level for 700-nm NIR fluorescence, 800-nm NIR fluorescence, autoradiography, and HE histopathologic staining. When multimodal FMs are combined with a new technique for simultaneous same-slide NIR fluorescence imaging, autoradiography, and HE staining, macroscopic in vivo images can now be studied unambiguously at the microscopic level.

Diagnosis difficulties for nodular thyroid disease. Case report

This article analyzed the tactical error in the diagnosis of nodal thyroid diseases. At the moment, thereis a wide arsenal of instrumental studies, with high accuracy the correct diagnosis before surgery. For the diagnosis of thyroid cancer is common to use a triad of research: ultrasound thyroid hormone study (TSH, fT4), fine-needle aspiration biopsy. If you suspect a metastasis of differentiated thyroid cancer in addition to biopsy it is advisable to explore the washout of the needle for thyroglobulin. In case of suspicion of occult sclerosing microcarcinoma form for the differential diagnosis with aberrant thyroid tissue expedient to thy-roid scintigraphy with pertechnetate. In carrying out scintigraphy with 99mTc pertechnetate sodium extra thyroid tissue accumulates radiopharmaceutical, and lymph node metastaseschanged not

Evaluation of salivary function in patients with burning mouth syndrome.

To investigate salivary function in patients with primary burning mouth syndrome (BMS) compared with control and to evaluate salivary hypofunction using salivary gland scintigraphy (SGS). A total of 33 patients with primary BMS and 30 control subjects were enrolled in our study. The severity of the pain and the burning sensation on a 10-cm visual analog scale (VAS) and the Oral Health Impact Profile-14 (OHIP-14) were assessed. Unstimulated and stimulated salivary flow rates (SFRs) were measured. (99m) Tc pertechnetate SGS was used to evaluate salivary gland function. Unstimulated SFR in patients with BMS was significantly lower than that in the control group (0.11±0.15 vs 0.21±0.16mlmin(-1) , P=0.014). There was no significant difference in stimulated SFR between the two groups. The VAS scores for oral pain and burning sensation, the total OHIP-14 score, and salivary gland function by salivary scintigraphy were not significantly different between BMS patients with normal flow rate and hyposalivation. Patients with primary BMS exhibited a significant decrease in unstimulated SFR compared with control group. In addition, we could not find any difference in salivary gland function between BMS patients with or without hyposalivation.

99mTc-labeled HYNIC-DAPI causes plasmid DNA damage with high efficiency.

99mTc is the standard radionuclide used for nuclear medicine imaging. In addition to gamma irradiation, 99mTc emits low-energy Auger and conversion electrons that deposit their energy within nanometers of the decay site. To study the potential for DNA damage, direct DNA binding is required. Plasmid DNA enables the investigation of the unprotected interactions between molecules and DNA that result in single-strand breaks (SSBs) or double-strand breaks (DSBs); the resulting DNA fragments can be separated by gel electrophoresis and quantified by fluorescent staining. This study aimed to compare the plasmid DNA damage potential of a 99mTc-labeled HYNIC-DAPI compound with that of 99mTc pertechnetate (99mTcO4 −). pUC19 plasmid DNA was irradiated for 2 or 24 hours. Direct and radical-induced DNA damage were evaluated in the presence or absence of the radical scavenger DMSO. For both compounds, an increase in applied activity enhanced plasmid DNA damage, which was evidenced by an increase in the open circular and linear DNA fractions and a reduction in the supercoiled DNA fraction. The number of SSBs elicited by 99mTc-HYNIC-DAPI (1.03) was twice that caused by 99mTcO4 − (0.51), and the number of DSBs increased fivefold in the 99mTc-HYNIC-DAPI-treated sample compared with the 99mTcO4 − treated sample (0.02 to 0.10). In the presence of DMSO, the numbers of SSBs and DSBs decreased to 0.03 and 0.00, respectively, in the 99mTcO4 – treated samples, whereas the numbers of SSBs and DSBs were slightly reduced to 0.95 and 0.06, respectively, in the 99mTc-HYNIC-DAPI-treated samples. These results indicated that 99mTc-HYNIC-DAPI induced SSBs and DSBs via a direct interaction of the 99mTc-labeled compound with DNA. In contrast to these results, 99mTcO4 − induced SSBs via radical formation, and DSBs were formed by two nearby SSBs. The biological effectiveness of 99mTc-HYNIC-DAPI increased by approximately 4-fold in terms of inducing SSBs and by approximately 10-fold in terms of inducing DSBs.

Parathyroid dual tracer subtraction scintigraphy: small regions method for quantitative assessment of parathyroid adenoma uptake.

The aim was quantitative assessment of parathyroid adenoma (PTA) uptake in dual tracer dynamic scintigraphy. In 78 patients, median age 58 (19-80) years, surgically treated for primary hyperparathyroidism (PHPT), with parathyroid hormone median 125 (70-658) pg/ml, we performed preoperative parathyroid scintigraphy, following EANM guidelines of subtraction and double-phase protocol (2009) using two tracers: Tc-99m pertechnetate and Tc-99m MIBI. In addition to standard subtraction processing and visual interpretation of delayed MIBI planar images of neck and mediastinum in oblique sections (positions according to ultrasound PTA localisation), we developed Submarine processing software that enables selecting custom regions grid sizes ≥6 mm (as this solution was not present in commercial software) to follow time activity curve changes in thyroid tissue and PTA. Histopathology in 53/78 patients revealed PHPT and in 25/78 patients thyroid nodular disease only, and thyroid malignancy occurred in total of 15/78 (19 %) patients. PHPT group included 44 solitary PTA, 8 patients with hyperplasia and one parathyroid carcinoma. The median macroscopic volume of PTA was 717.5 (15-6125) mm(3). Concomitant PHPT and thyroid nodular disease occurred in 24/53 patients and among them 8 patients had thyroid malignancies. PTA showed typical pattern of late peak on time activity curves characterized by median start time on 15 (10-25) min, the peak amplitude mean 19 (±5) % above thyroid declining washout curve, and duration of peak 6 (4-10) min, allowing PTA to "emerge" like submarine, independent from thyroid tissue and lesions. The ratio of PTA-to-normal thyroid uptake at peak maximum was 1.35 (±0.21). The thyroid TACs results of normal 29/78 (37 %) patients, benign nodular 34/78 (44 %) patients, and malignancy in 15 (19 %) patients were all presented by declining exponential curves. The slope analysis of TACs in normal thyroid tissue, thyroid benign and malignant lesions (linear fitted logarithm of TAC) showed no difference (the same negative slope: -0.04). Submarine processing was sensitive in detection of small lesions, in hyperplasia, and concomitant thyroid nodular disease. The novel Submarine processing confirmed specific PHPT pattern and was effective in the group with potential pitfalls of standard interpretation, increasing sensitivity and specificity of standard processing subtraction algorithm. Prolonged MIBI accumulation was present in malignant as well as benign thyroid nodules with identical TAC slope.