Lebriz Uslu

Incidental Detection of Follicular Thyroid Carcinoma in 68Ga-PSMA PET/CT Imaging

Prostate-specific membrane antigen (PSMA) is a type II transmembrane protein. It has been shown to be expressed in various solid malignant neoplasms. We report a case of a prostate cancer patient who underwent 68Ga-PSMA PET/CT imaging. There is a large thyroid nodule in the right thyroid gland, which had intense PSMA accumulation. Follicular thyroid lesions can be seen on 68Ga-PSMA PET/CT imaging.

Comparison of 99mTc-HYNIC-TOC and HYNIC-TATE octreotide scintigraphy with FDG PET and 99mTc-MIBI in local recurrent or distant metastatic thyroid cancers.

Aim There have been various studies for early diagnosis of local recurrent or distant metastatic thyroid cancers. The aim of this study is to evaluate the clinical utility of 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE, octreotide derivatives, to detect recurrences or distant metastases in 131I-negative thyroglobulin positive thyroid cancer patients and to compare the lesions with FDG PET and 99mTc-MIBI studies in the same patient group. Patients and Methods Twenty differentiated thyroid cancer patients, 7 male and 13 female, mean age 54.6 ± 15.3 (range 13–78 years), were included in this study. Eighteen patients had papillary thyroid cancer and 2 had follicular thyroid cancer. Fifteen patients received HYNIC-TOC and 5 patients received HYNIC-TATE as a radiopharmaceutical. All patients underwent whole-body scan 1 and 4 hours after injection of octreotide derivatives and SPECT imagings were performed from the suspicious sites. The lesions that were seen in 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE studies were compared with 99mTc-MIBI and FDG-PET studies. Results Among 99mTc-HYNIC-TOC and 99mTc-HYNIC-TATE scintigraphies, 15 patient studies were evaluated as true positive (75%) and 5 were false negative (25%). The total number of lesions in octreotide scintigraphy was 48 in 20 patients. Of 20 patients, 19 had FDG-PET study, 15 of them were evaluated as true positive (78.9%), and 4 them were evaluated as false negative (21.1%). Total number of lesions in FDG PET was 74. 99mTc-MIBI study was positive in 11 patients (55%) and negative in 9 patients (45%). Total number of lesions in 99mTc-MIBI was 25. Conclusion Technetium-labeled somatostatin receptor scintigraphy analogues HYNIC-TOC and HYNIC-TATE are useful imaging alternatives in somatostatin receptor expressing thyroid cancer patients. Radiolabeling is easy and they are readily available for routine use.

Clinical value of technetium-99m-labeled octreotide scintigraphy in local recurrent or metastatic medullary thyroid cancers: a comparison of lesions with 18F-FDG-PET and MIBI images.

AimVarious studies have been conducted for determining the most optimal method for the early diagnosis of local recurrent or distant metastatic thyroid cancers. The aim of this study was to evaluate the clinical utility of technetium-99m (Tc-99m)-labeled octreotide derivatives in the detection of recurrence or distant metastases in medullary thyroid cancer patients and to compare the lesions with those detected using 18F-fluorodeoxyglucose (18F-FDG)-PET and Tc-99m MIBI studies in the same patient group. Patients and methodsSixteen medullary thyroid cancer patients [two male and 14 female; mean age 52.0±14.1 years (range 13–72 years)] were included in this study. All patients underwent a whole-body scan 1 and 4 h after injection with octreotide derivatives and single photon emission computed tomography images were taken of the sites suspicious for metastasis. The lesions seen in Tc-99m HYNIC octreotide studies were compared with those seen in 18F-FDG-PET and Tc-99m MIBI studies. ResultsAmong the Tc-99m-labeled octreotide scintigraphy studies, nine were evaluated as true positive (56.2%) and one was evaluated as false positive (6.2%); six were false negative (37.5%). In 16 patients, the total number of lesions seen on octreotide scintigraphy was 21. Thirteen of the 16 patients underwent 18F-FDG-PET imaging. Of the 13 patients studied, 10 showed true-positive (76.9%) and three showed false-negative (23.1%) results. The total number of lesions seen on 18F-FDG-PET was 23. The Tc-99m MIBI study yielded positive results in seven of 16 patients (43.7%) and negative results in nine patients (56.3%). The total number of lesions on Tc-99m MIBI was 12. ConclusionThe Tc-99m-labeled somatostatin receptor scintigraphy analogs HYNIC-tyrosine octreotide and HYNIC-TATE are useful imaging alternatives in somatostatin receptor-expressing thyroid cancers. Radiolabeling using these analogs is easy and they are readily available for routine use.

Effects of altered thyroid states on oxidative stress parameters in rats.

Abstract Background: Thyroid hormones are effective on oxidant-antioxidant balance by leading basal metabolic rate. In this study, the effects of altered thyroid states on low density lipoprotein (LDL) oxidation and oxidative stress parameters were investigated in an experimental animal model. Methods: Thirty female Wistar Albino rats were equally divided into 3 groups as follows: control group; hypothyroid group (methimazole (75 mg/100 g was added to diet); hyperthyroid group [L-thyroxine (0.4 mg/100 g was added to diet)]. Oxidized LDL (ox-LDL) levels, thyroid, and lipid parameters were determined in serum. Also lipid peroxidation (LPO), sialic acid (SA) and glutathione levels (GSH), as well as superoxide dismutase (SOD) and catalase (CAT) activities were determined in tissue samples. Results: A significant increase in lipid parameters was observed in hypothyroid group, whereas these parameters were decreased in hyperthyroid group compared to control group. For ox-LDL levels, a significant increase was observed both in hypothyroid and hyperthyroid groups. In brain, liver and kidney tissues, LPO and SA levels were increased, whereas GSH levels were decreased both in hypothyroid and hyperthyroid groups. The SOD and CAT activities were significantly decreased in hypothyroid group, however, they were increased in hyperthyroid group compared to control group. Both hypothyroid and hyperthyroid conditions modify the oxidant-antioxidant state in serum and tissues. Conclusions: Increased SOD and CAT activities in hyperthyroid group suggest that elevated thyroid hormones can reduce oxidative stress by maintaining antioxidant defense and they might have a protective effect on some tissues against oxidants.

Prognostic significance and predictive performance of volume-based parameters of F-18 FDG PET/CT in squamous cell head and neck cancers

AIM It has been previously reported that metabolic tumor volume on positron emission tomography-computed tomography predicts disease recurrence and death in head-and-neck cancer. In this study, we assessed the prognostic value of metabolic tumor volume measured using F18-Fluorodeoxyglucose PET/CT in patients with head and neck squamous cell carcinoma. MATERIALS AND METHODS We analyzed the imaging findings of 74 patients (age 57±16) retrospectively, with head and neck cancer who underwent PET/CT scan for staging and after treatment. Forty-tree patients had nasopharynx, 15 patients had hypopharynx, 9 patients had larynx, and 7 patients had oropharynx cancer. The MTVs of primary sites with or without lymph nodes were measured, and outcomes were assessed using the treatment response evaluation by the Response Evaluation Criteria in Solid Tumors and recurrence events during follow-up. RESULTS A total of 48 patients had complete response or no recurrence was detected as of in the last follow-up. Of the first PET/CT scan, the median primary tumor SUVmax was 18.8 and the median nodal SUVmax was 13.4. The median primary tumor MTV% 50s ranged from 11.12 cm3 to 16.28 cm3, and the MTV after the therapy ranged from 1.18 cm3 to 3.51 cm3. CONCLUSION Metabolic tumor volume (MTV) represents tumor burden, which shows F18-Fluorodeoxyglucose uptake and has a potential value in predicting short-term outcome and disease-free survival in patients with head and neck cancer.

Preoperative and postoperative (18)FDG PET/CT and bone scintigraphy images in a patient with parathyroid adenoma.

A 35-year-old male patient with generalized body pain had multiple hyperactive lesions on bone scan, suggestive of metastatic disease. FDG PET/CT scan performed 2 weeks later showed multiple hypermetabolic lesions on skeletal system; also a hypermetabolic and hypodense lesion was present adjacent to the left thyroid lobe, suggestive of primary parathyroid adenoma and multiple brown tumors. Serum parathyroid hormone level was elevated, and parathyroid scintigraphy confirmed parathyroid adenoma. The patient underwent parathyroidectomy operation, and histopathology result revealed parathyroid adenoma. Five months after the operation, complete metabolic regression was observed on PET/CT, whereas bone scan did not show any significant difference.

Bilateral breast uptake of radioiodine in a male patient with gynecomastia: A case report.

A 56-year-old male patient with papillary thyroid carcinoma was given radioiodine for the treatment of persistent disease. Post radioiodine whole body scan revealed uptake at the thyroidal region and bilateral uptake at the upper thoracic region. Single photon emission computed tomography/computed tomography (SPECT/CT) confirmed uptake at the left thyroid lobe, and additional symmetrical mammary gland uptake was observed at both breasts. The patient had obesity-related gynecomastia, but he did not have any history of breast cancer, mastitis, hyperprolactinemia, or galactorrhea. Although breast uptake of radioiodine is a common finding in postpartum or lactating women, it is uncommon in male patients. To our knowledge, this is the first case of a male patient with breast uptake of radioiodine documented with SPECT/CT. SPECT/CT is useful in male patients in the differentiation of benign breast uptake with lung metastases or axillary metastases of thyroid cancer.

Comparison of day 3 and day 5 thyroglobulin results after thyrogen injection in differentiated thyroid cancer patients

Background: It is necessary to stimulate serum thyroid-stimulating hormone (TSH) levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH) for radioactive iodine (RAI) therapy. Thyrotropin alfa (Thyrogen) has many advantages over THW. Radiation dose to laboratory staff while drawing blood for tests on the day 5 is one of the disadvantages of preferring Thyrogen. Our aim was to compare day 3 and day 5 blood test results after Thyrogen injections. Material and method: In our study, Thyrogen was preferred in 32 differentiated thyroid cancer patients with a mean age of 50.5 ± 12.3 years. Thyrogen was injected on day 1 and day 2 intramuscularly in all patients before I-131 was given on day 3. A total of 22 patients received 5 mCi RAI for ablation control scintigraphy and 10 patients received 100–250 mCi RAI for ablation or therapy (high-dose group). Blood tests were performed on day 3 and day 5 after Thyrogen injections. Results: Mean TSH level was 98.1 mg/dl for day 3 and 29.5 mg/dl for day 5. In the diagnostic group, thyroglobulin (Tg) and anti-Tg levels were nearly the same on day 3 and day 5. In the therapy group, day 5 Tg levels were higher than day 3. Conclusion: After Thyrogen injection of two consecutive days, blood sampling might be enough on day 3. Day 5 blood sampling may not be necessary routinely for radiation protection of laboratory staff. For the diagnostic group, if Tg and anti-Tg is normal then 5 mCi imaging may not be necessary.

Clinical significance of standardized uptake values in thyroid incidentaloma discovered by F-18 fluorodeoxyglucose positron emission tomography/computed tomography

Aim of Study: While using F-18 fluorodeoxyglucose (FDG) positron emission tomography computed tomography (PET/CT) for other than thyroid disease, an increased frequency of incidentally discovered areas of focally or diffuse increased uptake within the thyroid gland can be seen. We aimed to find the focal thyroid FDG uptake and compare the maximum standardized uptake value (SUVmax) results with cytology and histology results. Materials and Methods: We examined PET scan reports for all patients undergoing FDG PET/CT investigation over a 10-year period in a single center. Twelve thousand seven hundred and ninety-six patients underwent FDG PET/CT scanning in one PET/CT unit. Within this group, 526 patients had diffuse, focal, or multifocal FDG uptake. About 305 of 526 patients (57.9%) showed diffuse FDG uptake and 221 (42%) showed focal uptake on thyroid gland. Results: The malignant group thyroid nodule sizes were between 8 and 39 mm (21.1 mm average, standard deviation [SD] ±7.3) on ultrasonography (USG) examination. These nodules have SUVmax values between 2.3 and 31.2 (average 8.8 SD ± 5.7). Benign group thyroid nodule sizes were between 5 and 46 mm (average 18.3 mm, SD ± 5.8) on USG examination. There were no significant correlations between SUVmax of the incidental focal thyroid lesions seen on FDG PET/CT and fine needle aspiration biopsy results. Conclusion: There is a relatively high possibility of a malignant lesion in thyroid incidentaloma. FDG uptake of these lesions is not a useful tool in absolute discrimination between malignancy and benign lesion. The presence of primary or secondary malign lesion is diagnosed in 34.1% of the patients who are found to have incidental focal FDG uptake within thyroid gland in PET/CT scans, but we suggest that the thyroid incidentalomas detected on FDG PET/CT should be further examined with USG and scintigraphy.

The Effects of Hyperbaric Oxygen Treatment on Total Antioxidant Capacity and Prolidase Activity after Bile Duct Ligation in Rats.

ABSTRACT Background: Hyperbaric oxygen (HBO) therapy may improve cholestasis, increase hepatic regeneration, and decrease oxidative stress in liver. In this study, we aimed to investigate the effects of HBO therapy on hepatic oxidative stress parameters, such as total thiol groups (T-SH), protein carbonyl (PCO), and total antioxidant capacity (TAC) as well as the predictive value of the noninvasive biochemical marker, sialic acid (SA), and prolidase activity in bile duct ligation (BDL)-induced oxidative damage and fibrosis in rats. Methods: We divided 32 adult male Sprague Dawley rats into four groups: sham, sham + HBO, BDL, and BDL + HBO; each group contained eight animals. We placed the sham + HBO and BDL + HBO groups in an experimental hyperbaric chamber, in which we administered pure oxygen at 2.5 atmospheres for 90 min on 14 consecutive days. Results: The application of BDL significantly increased PCO levels and prolidase activity, and decreased T-SH and TAC levels. HBO significantly decreased PCO levels and prolidase activity and increased T-SH and TAC levels in the liver tissues. There was no significant difference in sialic acid levels between any groups. Conclusions: These results indicate that HBO therapy has hepatoprotective effects on BDL-induced injury by decreasing PCO and prolidase activity and increasing antioxidant activities. We therefore suggest that HBO therapy may be useful after BDL-induced injury.