Thyroid cancer in pediatric age group: an institutional experience and review of the literature.

Very few have been reported on children with differentiated thyroid cancer (DTC), although 15% of them are diagnosed below 20 years of age. Children with DTC present with more advanced disease; however, they have a more favorable outcome. In this paper, we aimed to present the data in our institution on pediatric DTC patients, making an emphasis on the risk factors of metastasis and recurrence, as well as to the outcome of treatment. Clinical data of 50 pediatric patients referred to our institution for radioiodine treatment (RAI) between 1976 and 2010 were obtained. Papillary carcinoma was the most common histopathologic diagnosis (36 patients) followed by papillary carcinoma with follicular variant (10 patients). Multifocality was reported in 66% of the pathology reports. At the time of diagnosis 35 patients had regional lymph node metastasis, 18 had local invasion, and 11 had distant metastasis. No distant metastasis was present in patients with unifocal disease (P=0.018). The mean duration of follow-up was 77.6±62.7 months. Patients with local disease had longer disease-free survival than patients with distant metastasis (P=0.033). Despite the small number of patients, the follow-up was relatively long and the presented results confirmed overall good prognosis in children with DTC.

Cerebral blood flow and cognitive function in obstructive sleep apnea syndrome.

Neuropsychological deficits are among the main symptoms of obstructive sleep apnea syndrome (OSAS), which could be related to impaired cerebral blood flow (CBF). We conducted a study in 20 subjects tested in our Sleep Laboratory, to assess regional CBF and cognitive function in OSAS. Our measurements included technetium-99m hexamethylamino propylenamine oxime brain perfusion scintigraphy in wakeful state, i.e. in the morning after polysomnography and also cognitive function tests after polysomnography, in 20 patients, 16 male and 4 female, aging between 30 and 60 years. We found that apnea-hypopnea index was greater than or equal to 5 in 16 (85%) subjects, consistent with OSAS. Mean arterial oxygen saturation during sleep was correlated with CBF in all regions. Cognitive function test scores in verbal memory were positively correlated with percentage of sleep duration with less than 90% of oxygen saturation during sleep. Cerebral blood flow was not uniform in OSAS patients, and was significantly lower in the left frontal and left temporal regions as compared to that of these regions on the right hemisphere. In conclusion, our findings indicated association of CBF and verbal memory with hypoxemia during sleep and decreased perfusion after apneic episodes in the left frontal and temporal lobes in OSAS patients, which could also indicate impairment of upper airway motor control.

Detection of ectopic gastric mucosa using 99mTc pertechnetate: review of the literature.

Technetium-99m ((99m)Tc) pertechnetate scintigraphy in a child with acute gastrointestinal bleeding of unknown origin suggests ectopic gastric mucosa caused by Meckel's diverticulum or gastrointestinal duplication cysts. Our objective was to define the patterns of scintigraphic findings likely to be encountered in patients with ectopic gastric mucosa with illustrative cases and to review the literature. Fifty children (age 1 year to 14 years) were evaluated for ectopic gastric mucosa using (99m)Tc pertechnetate scintigraphy. Functioning ectopic gastric mucosa was detected in eight patients with Meckel's diverticula and three patients with bowel duplication. Three patients showed atypical findings on scintigraphy which were perforated appendix, calyceal stasis, and regional enteritis. Ectopic functioning gastric mucosa in Meckel's diverticulum is visualized simultaneously with the stomach, whereas in intestinal duplications tracer activity can be visualized in the dynamic sequence or before gastric tracer visualization in an irregular pattern. A variety of scintigraphic patterns can be found in patients with ectopic gastric mucosa undergoing (99m)Tc pertechnetate scintigraphy depending on the location and size of the ectopic tissue. Also, acquisition of delayed images is useful when the initial images are equivocal in children.

Assessment of cardiac parameters using gated myocardial perfusion and echocardiography in children.

Echocardiographic and radionuclide techniques are the most common techniques currently used to assess ventricular function. The aim of our study was to assess the performance of two well-known methods for analysis of gated myocardial perfusion with comparison to echocardiography in children. We analyzed the data from 64 children referred for myocardial perfusion scintigraphy. All underwent echocardiography and stress gated myocardial perfusion scintigraphy, except 5 who had only rest scintigraphy. We calculated the left ventricular volumes and ejection fractions. The parametric information from the echocardiographic reports was compared to the data obtained using gated myocardial perfusion. The reliability between the quantitative gated scintigraphy, the Emory cardiac toolbox, and echocardiography for end-diastolic and end-systolic volumes and ejection fractions in studies performed at rest were calculated at 0.85, 0.86 and 0.97, respectively using Cronbach's alpha coefficient. The values in stress studies were 0.83, 0.86 and 0.90, respectively. There was a high correlation, with r more than 0.88, between quantitative gated scintigraphy and the Emory cardiac toolbox for ejection fractions, and end-diastolic and end-systolic volumes, in studies performed both under stress and at rest. Weak correlation was observed between quantitative gated scintigraphy and the Emory cardiac toolbox compared to echocardiography, especially when considering ventricular volumes in stress studies. Although high correlation was observed between quantitative gated scintigraphy and the Emory cardiac toolbox, comparison with echocardiography showed poor agreement for both, meaning that scintigraphy is less suitable for assessing left ventricular volumes, and less reliable in assessment of ejection fractions. Echocardiography seems to remain the most widely used and reliable technique for this part of the diagnostic work up.

Relation between radionuclide imaging and pathologic findings of ureteropelvic junction obstruction in neonatal hydronephrosis.

OBJECTIVE: An excessive amount of collagen fibers around the muscle cells in the ureteropelvic junction could be responsible for obstruction in patients with hydronephrosis. We aimed to elucidate the ultrastructure of the ureters and correlate this finding with the prognostic outcome and to correlate the histopathological findings with diuretic radionuclide renography findings. MATERIAL AND METHODS: Biopsy specimens of 20 children who underwent dismembered pyeloplasty for ureteropelvic junction obstruction were analyzed. The patients were grouped according to their age: infants (<12 months) and others (>12 months). Diuretic radionuclide imaging was performed using (99m)Tc mercaptylacetyltriglycine in the pre- and postoperative periods. Changes in differential renal function and excretion patterns on diuretic renography were evaluated in relation to the findings noted on histopathological examination of the biopsy specimens. Excretion patterns were classified as follows: A, normal; B, responsive to diuretic; C, minimal response to diuretic with some excretion after postural change; and D, very poor/no drainage despite diuretics. Biopsy materials were analyzed for the presence and extent of inflammation, fibrosis and changes in the smooth muscle layer using Masson's trichrome stain and immunohistochemical staining. Histopathological findings were graded from zero to three, depending on severity. RESULTS: In patients aged <12 months, preoperative differential renal function (DRF) was associated with fibrosis (F) and smooth muscle hypertrophy (SMH) [mean (SD) DRF for both F and SMH were Grade 0-1, 47.8% (6.4%); Grade 2-3, 36.2% (11.3%); p<0.05]; and change in DRF was associated with inflammation [Grade 0-1, -0.1% (4.0%); Grade 2-3, 5.8% (3.0%); p<0.05]. Excretion patterns or improvement in excretion were not associated with any of the histopathological features. Change in DRF was significantly associated with inflammation Grade 2-3 (beta coefficient, 5.8; 95% CI 1.4-10.3). CONCLUSIONS: Histopathological evaluation of renal parenchymal biopsy specimens obtained during pyeloplasty may be useful to provide an objective method for predicting the recovery of renal function. In addition, this will allow comparison of the types of histopathological alterations with the changes in differential renal function in order to predict the potential final improvement.

Risk factors of pulmonary thromboembolism in patients from a university hospital.

OBJECTIVE: To investigate the impact of risk factors in the diagnosis of pulmonary thromboembolism. METHODS: This was a retrospective study of 295 patients with suspicion of pulmonary embolism (PE), of whom 154 were referred from outpatient and 141 from inpatient departments for a period of 24 months (2000-2001) in Hacettepe University Hospital in Ankara. RESULTS: Pulmonary thromboembolism was diagnosed in 71 patients (24.1%) with high probability ventilation/perfusion scintigraphy. Chronic renal failure, trauma, history of pulmonary thromboembolism and type of care were significantly associated with pulmonary thromboembolism, after adjusting for age and gender. CONCLUSION: This retrospective study revealed that clinicians should keep PTE in mind, especially in the presence of risk factors. Ventilation/perfusion scintigraphy has been the procedure of choice for the assessment of patients with suspected PE.

A report on the incidence of intestinal 99mTc-methylene diphosphonate uptake of bone scans and a review of the literature.

BACKGROUND: In addition to well-known specific conditions for soft-tissue uptake of bone-seeking radiotracers, there is a limited number of reports on intestinal uptake of (99m)Tc-methylene diphosphonate ((99m)Tc-MDP) on bone scans. AIM: To describe the incidence of intestinal accumulation of (99m)Tc-MDP on bone scans in adult patients, define the patterns of this unusual finding and review the literature on its causes. METHODS: Two thousand, one hundred and forty-four consecutive patients have been evaluated for intestinal (99m)Tc-MDP uptake on bone scans. Intestinal uptake was observed visually 3-4 h after the administration of the radiopharmaceutical. A whole-body bone scan and various spot views of the abdomino-pelvic region were obtained with a dual-headed gamma camera to evaluate the intestinal uptake. Delayed scans were also obtained as well as co-relative imaging and/or colonoscopic studies in some of intestinal uptake patients. Six patients had delayed scans of the abdomino-pelvic region. Fourteen patients had comparable scans either a year before or a year later. The positive intestinal uptake scans were further grouped according to the localization and intensity (mild uptake: lower than iliac bone; moderate uptake: equal to iliac bone; significant uptake: higher than iliac bone). RESULTS: Twenty-two (17 female, five male) patients out of 2144 with a mean age of 57 years showed intestinal (99m)Tc-MDP uptake. The localization was mainly (20/22) in the right abdomino-pelvic region projecting on and in the configuration of ascending colon while one patient showed intestinal uptake all over the abdomen and one displayed diffuse intestinal radioactivity in his right hemithorax. The majority of the cases showed moderate to intense intestinal uptake (18/22). Six patients showed a decrease, disappearance or alteration in the intestinal uptake on the delayed images. Re-evaluation bone scans in five patients 1 year later showed no intestinal uptake this time. Among nine patients with prior bone scans 1 year before, intestinal uptake was negative in seven at that time. No significant pathology was obtained on the correlative images. CONCLUSION: (99m)Tc-MDP uptake can be observed in the intestines in 1% of bone scans with a prominent localization in the ascending colon and rarely all over the intestines or in thorax due to Chilaiditi's syndrome, as well. The mechanism of intestinal uptake is still unclear in some of the patients. Delayed imaging, additional spot views and SPECT studies help in the differentiation of this finding from possible misinterpretation. Intestinal (99m)Tc-MDP uptake on bone scan could be an intermittent process and should be included among other well-known reasons of soft-tissue uptake.

Comparison of bone scintigraphy with serum tumor markers of CA 15-3 and carcinoembryonic antigen in patients with breast carcinoma.

OBJECTIVE: To compare the bone scintigraphy findings with a carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA 15-3) levels in breast carcinoma patients. We also investigated the relationship between anatomical bone type and its effect on tumor marker levels. METHODS: The study was consisted of retrospective evaluation of 120 bone scans of patients with breast carcinoma admitted to the Nuclear Medicine Department, Medical Faculty, Hacettepe University, Ankara, Turkey between January 2003 and December 2004. The mean age of the patients was 54.7 years. We grouped the results of the bone scans into 3 as normal, equivocal and metastatic. Carcinoembryonic antigen and CA 15-3 levels were recorded from the files of the patients. Upper cut levels of 4.8 U/ml for CEA and 38 U/ml for CA 15-3 was accepted. Metastatic bone areas were distributed according to their anatomical location as long, short, flat, irregular and sesamoid and effect of bone type on tumor marker was investigated. RESULTS: In 16 of the patients, bone scintigraphy revealed metastases. Sixty-one patients had normal scans and in 47 patients metastases could not be ruled out. In patients with metastases, CA 15-3 was elevated in 8 and CEA was higher than the upper limit in 6. For CEA and CA 15-3, the anatomical type of bone has no any effect on serum tumor marker concentration between patients with normal and elevated levels of tumor markers in metastatic patients. CONCLUSION: Tumor markers are not solely enough in predicting bone metastases. Bone scintigraphy and tumor markers should be both used in management of patients with breast carcinoma. The anatomical type of bone has no any effect on elevation of serum tumor marker concentration.