The Clinical Significance of Incidental Parotid Uptake in a PET/CT Study: A Diagnostic Algorithm.

BACKGROUND: Patients diagnosed with cancer do not have sufficient clinical data for the management of incidental parotid lesions. We aimed to reveal the importance of randomized parotid lesions encountered during oncologic F-18 fluorodeoxyglucose positron emission tomography (FDG PET/CT) imaging in our clinical practice and the diagnostic algorithm of such lesions. METHODS: We performed a database search of PET/CT records generated from 2009 to 2015 for "parotid" in reports of patients who underwent PET/CT examination for a known malignancy elsewhere, or cancer screening. RESULTS: Incidental parotid FDG uptake on PET/CT had a prevalence of 1.1%. The incidence of parotid metastasis in our series was 36.4%, and 75% of them had malign melanoma metastasis. Of the 11 cases, 5 were of Warthin tumours, and Warthin tumours showed stronger GLUT1 expression than metastatic parotid lesions. CONCLUSION: In patients with malignancy elsewhere, focal involvement of FDG by the parotid gland, especially if malignant melanoma or SCC is absent, should not be considered a metastatic disease without histopathologic confirmation. If parotid disease would change the patient's treatment plan and disease stage, the parotid lesion should be evaluated by additional methods, such as fine needle aspiration biopsy.

Radioprotective Effects of Amifostine, L-Carnitine and Vitamin E in Preventing Early Salivary Gland Injury due to Radioactive Iodine Treatment.

OBJECTIVE: Standard treatment of differentiated thyroid cancer includes total thyroidectomy and high-dose Radioactive Iodine Therapy (RIT) for ablation of remnant thyroid tissue. When administered systemically, RIT can cause radiation-induced damage in non-targeted normal tissues. The aim of the present study was to compare the protective effects of amifostine (AMI), LCarnitine (LC), and Vitamin E (EVIT) against high dose radioactive iodine treatment induced Salivary Gland (SG) damage using SG scintigraphy and histopathological examination. METHODS: Forty adult guinea pigs were studied. Twenty guinea pigs receive 555-660 MBq 131Iodine intraperitoneally (IP) to ablate the thyroid and impair the parenchymal function of the SGs. The animals were divided into eight groups as follows: (1) Group 1 (control): 1 mL IP PS (physiological saline); (2) Group 2: single dose of 200 mg/kg IP AMI one hour prior to 1 mL IP PS; (3) Group 3: 200 mg/kg IP LC and 1 mL IP PS for 10 days; (4) Group 4: 40 mg/kg intramuscular (IM) EVITand 1 mL IP PS for 10 days; (5) Group 5: IP RIT after premedication; (6) Group 6: Single dose of 200 mg/kg IP AMI one hour prior to RIT and IP RIT after premedication; (7) Group 7: IP RIT after premedication and 200 mg/kg IP LC for 10 days starting one day before RIT; and (8) Group 8: IP RIT after premedication and 40 mg/kg IM EVIT for 10 days starting one day before RIT. Scintigraphy was performed 1 month after treatment. SGs were examined by light microscopy and a histopathological scoring system was used to assess the degree of SG damage. RESULTS: There were significant differences in the body weight and thyroid hormone levels between the groups after treatment. CONCLUSION: The individual use of AMI, LC and EVIT for radioprotection yield different levels of protection against radioactive iodine treatment injury in SGs; however, none of the agents could provide absolute protection at the doses administered in this experimental model.

Biochemical Recurrence of Prostate Cancer Presenting as Solitary Testicular Metastasis on 68Ga-Labeled Prostate-Specific Membrane Antigen Ligand Positron Emission Tomography/Computed Tomography.

Prostate adenocarcinoma (PCa) is the most frequently diagnosed malignancy in the male population, with the most common sites for secondary lesions being the lymph nodes, bones, and lungs. Testicular metastases from PCa are very rare and mostly identified incidentally after therapeutic orchiectomy for advanced PCa or during autopsy. Here we present a case involving a 64-year-old man with biochemical recurrence of castrated oligometastatic PCa that presented as solitary testicular metastasis on Ga-PSMA ligand positron emission tomography/computed tomography.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Findings of Pancreatic Hemangiopericytoma.

A 42-year-old woman with a large pancreatic tumor had undergone 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging. Moderate metabolic activity was detected on the head of the pancreas. The tumor was resected and it was histopathologically diagnosed as malign pancreatic hemangiopericytoma (HPC). HPC is a rare soft tissue sarcoma. The tumor is considered aggressive with high rates of local recurrence and metastasis regardless the localization. Herein, we present the imaging characteristics of HPC with 18F-FDG PET/CT.

Liver Metastasis of Lung Cancer Detected with Similar Uptake Pattern on Bone Scintigraphy and Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography: What's the Pathophysiologic Mechanism?

Bone scintigraphy with 99mTc diphosphonates may exhibit extraosseous lesions in addition to metastatic lesions. Multiple factors can affect extraosseous 99mTc methylene diphosphonate (MDP) uptake. Similar uptake pattern of 99mTc MDP and fluorine-18 fluorodeoxyglucose (18F FDG) in hepatic metastasis was not already notified. In our case, initial tumor necrosis and subsequent intracellular calcification resulted in similar 99mTc MDP and 18F FDG accumulation in the metastatic area.

Intrathoracic toxic thyroid nodule causing hyperthyroidism with a multinodular normal functional cervical thyroid gland.

Radionuclide scintigraphy with I-131 and Tc-99m pertechnetate ((99)mTc04) has been widely used in detecting toxic nodules. Intrathoracic goiter usually presents as an anterior mediastinal mass. Mostly the connection between intrathoracic mass and the cervical thyroid gland is clearly and easily identified occurring as a result of inferior extension of thyroid tissue in the neck, which is called as secondary intrathoracic goiter. Completely separated, aberrant or in other words primary intrathoracic goiters arise as a result of abnormal embryologic migration of ectopic thyroid closely associated with aortic sac and descend into the mediastinum. Intrathoracic goiters are generally nontoxic nodules existing with mass effect without causing hyperthyroidism. However, mostly reported cases had enlarged thyroid glands in the neck. This report demonstrates the usefulness of I-131 and (99)mTc04 scintigraphy for detecting intrathoracic goiter causing hyperthyroidism with a normal functioned cervical thyroid gland.

The alteration of asymmetric dimetilarginine (ADMA) levels in cardiac and gastrocnemius muscles following radioactive iodine application in guinea pigs and the effect of L-carnitine on this alteration.

PURPOSE: Tissue levels of asymmetric dimetilarginine (ADMA) and symmetric dimetilarginine (SDMA) were investigated in cardiac ventricle and gastrocnemius muscles of guinea pigs treated with radioactive iodine (RAI) alone or in combination with L-carnitine (LC). MATERIAL AND METHODS: Group 1 received no treatment (control group). Group 2 received a total dose of 30 mCi⁻¹kg⁻¹ body weight iodine-131 alone. Group 3 received 200 mg⁻¹kg⁻¹ of LC for 10 days alone. Group 4 received 200 mg⁻¹kg⁻¹ of LC plus RAI therapy. Free thyroid hormones, ADMA and SDMA concentrations were measured. RESULTS: Serum free thyroid hormone concentrations were found decreased in the RAI and LC-RAI groups after RAI application. A significant decrease in ADMA and SDMA concentration was observed in ventricle muscle following RAI application. The LC-RAI group had significantly decreased ADMA levels in ventricle muscle compared with those of the control group. Similarly, SDMA concentrations in ventricle and gastrocnemius muscles of the LC-RAI groups were significantly lower than those of the control groups. CONCLUSIONS: Our results indicated that RAI appears to exert an inhibitory effect on ADMA and SDMA levels of ventricular muscle. LC administration when given adjuvant to RAI therapy may cause a marked decrease in ADMA concentrations of both ventricular and gastrocnemius muscles.

Melatonin administration acutely decreases the diffusing capacity of carbon monoxide in human lungs.

BACKGROUND: Most physiological measurements of the pulmonary diffusing capacity use carbon monoxide (CO) as a tracer gas. Similar to CO, melatonin binds the hemoglobin in the blood. OBJECTIVE: The present study was designed to assess the effect of exogenous melatonin administration on pulmonary functions including diffusing capacity for carbon monoxide (DL(CO)) in healthy subjects. METHODS: The study was performed in a randomized, double-blind, placebo-controlled manner. DL(CO) was measured in 22 healthy male volunteers (age 18-25 years) who were randomized to melatonin (n = 11) and placebo administration (n = 11). At baseline, DL(CO), alveolar volume (V(A)) and other spirometric parameters such as forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC), peak expiratory flow (PEF) and maximal voluntary ventilation (MVV) were measured. DL(CO) was then corrected for the hemoglobin concentration. Measurements were repeated in a double-blind fashion 60 min after the administration of melatonin (1 mg) or placebo. RESULTS: DL(CO) was significantly decreased (39.31 +/- 4.75 vs. 34.82 +/- 6.18 ml/min/mm Hg) 60 min after the melatonin administration (p = 0.01), while FEV(1), FVC, FEV(1)/FVC, PEF and MVV values did not demonstrate significant differences. Placebo administration did not result in significant alteration in any of these parameters. CONCLUSIONS: In healthy subjects, oral administration of melatonin acutely influences the DL(CO) without affecting other pulmonary function test results. We conclude that melatonin may have a reducing effect on the DL(CO) in the lungs.

Prevalence of the female athlete triad in edirne, Turkey.

The aim of this study was to determine the prevalence of the female athlete triad, which is a clinical condition defined as the simultaneous occurrence of disordered eating, amenorrhea, and osteopenia and/or osteoporosis in female athletes. A total number of 224 female athletes from Edirne city participated in our study. Eating attitudes test (EAT 40) and a self-administered questionnaire were used to assess disordered eating behavior and menstrual status respectively. The participants having both disordered eating and amenorrhea were performed dual energy x-ray absorptiometry to evaluate bone mineral density. Thirty seven subjects (16.8%) had disordered eating behavior and 22 subjects (9.8%) were reported to have amenorrhea. Six athletes (2.7%) met two criteria (disordered eating and amenorrhea) of the triad. Of these, only three athletes met all components of the triad. We have found that the prevalence rate of female athlete triad was 1.36% among young Turkish female athletes. Female athletes have under considerable risk for the disordered eating and amenorrhea components of the triad. Key PointsThe prevalence rate of the occurrence of whole criteria of the female athlete triad was 1.36 % in young Turkish athletes in Edirne.Female athletes who met whole criteria of female athlete triad are more prone to the eating disorders.The occurrence of disordered eating behavior was higher in female athletes according to general population.Amenorrhea prevalence was significantly higher in female athletes who had disordered eating.

Irbesartan has a masking effect on dipyridamole stress induced myocardial perfusion defects.

BACKGROUND AND AIM: The angiotensin II type 1 (AT1) receptor antagonist irbesartan is used for the treatment of hypertension, but its anti-ischaemic effect is not yet known. Our aim was to assess the effect of irbesartan administration on the diagnostic yield of 99mTc sestamibi single photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) after dipyridamole stress. METHODS: Our study group consisted of 13 patients (11 men and two women; mean age, 53.3 +/- 10.6 years; body mass index, 26.9 +/- 3.3 kg x m(-2)) with angiographically documented CAD. All patients underwent SmTc sestamibi SPECT studies at rest, before (STRESS-1) and 2 weeks after irbesartan (150 mg daily) administration (STRESS-2) at dipyridamole stress. The extent and severity of defects were analysed by using visual and quantitative 99mTc sestamibi SPECT. RESULTS: The mean summed stress score was significantly higher during the STRESS-1 study than the STRESS-2 study (13.2 +/- 7.4 vs. 11 +/- 7.4, P=0.003). The mean size of perfusion defects at stress was significantly larger for the STRESS-1 group than the STRESS-2 group (17.8% +/- 2.85% vs. 15.3% +/- 2.95%, P=0.01). CONCLUSION: Our study showed that the AT1 receptor blocker irbesartan reduces the extent and severity of 99mTc sestamibi perfusion defects after dipyridamole stress in patients with CAD. Irbesartan may alter coronary blood flow reserve. The continued use of irbesartan before stress myocardial perfusion SPECT has a masking effect on stress induced myocardial perfusion defects. For this reason AT1 receptor blockers must be stopped before stress myocardial perfusion scintigraphic examinations.

Technetium-99m sestamibi cavity/myocardium count ratio in the detection of left ventricular hypertrophy.

BACKGROUND AND HYPOTHESIS: Left ventricular hypertrophy (LVH) is an independent risk factor for cardiovascular mortality and morbidity. This study was designed to assess whether technetium-99m (99mTc) sestamibi cavity-to-myocardium count (c/m) ratio would differentiate LVH from normal geometry, and discriminate between the two patterns-concentric and eccentric--of LVH. METHODS: In all, 72 patients including 32 hypertensive patients with both normal 99mTc sestamibi single-photon emission computed tomography imaging and good-quality echocardiographic recordings were studied retrospectively. Four different patterns of left ventricular (LV) geometry were defined: normal (n = 47), concentric remodeling (n = 3), eccentric LVH (n = 13), and concentric LVH (n = 9). RESULTS: Left ventricular hypertrophy was detected in 22 of 32 hypertensive patients. The c/m ratio calculated on midventricular short-axis slices of dipyridamole-stress 99mTc sestamibi images was significantly decreased in patients with LVH compared with subjects with normal geometry (0.05 +/- 0.02 vs. 0.17 +/- 0.08, p = 0.001). A c/m ratio of <0.124 yielded a sensitivity of 86%, a specificity of 64%, and an overall diagnostic accuracy of 68% for detecting LVH. Negative correlations of c/m ratio were found to LV mass-index (r = -0.44, p = 0.004), septal width (r = -0.42, p = 0.008), posterior wall thickness (r = -0.39, p = 0.001), and relative wall thickness (r = -0.40, p = 0.001). Multiple linear regression analysis revealed that LV mass index was the single independent predictor of c/m ratio. Although both groups with concentric and eccentric LVH had a significantly lower mean c/m ratio than those with normal geometry (p = 0.01 and p = 0.01, respectively), no significant difference of c/m ratio was found between the two patterns of LVH. CONCLUSION: A new index, c/m ratio on 99mTc sestamibi images, has a potential to discriminate between LVH and normal geometry in subjects free of myocardial ischemia.