Clinical behaviour of papillary thyroid cancer oncocytic variant: stage-matched comparison versus classical and tall cell variant papillary thyroid cancer.

OBJECTIVE: Papillary thyroid cancer (PTC) has many variants and most of them are mild tumors. Oncocytic variant (OV) is a rare subtype of PTC. There are controversial results about its prognosis in the literature. We investigated its aggressivity and clinical course by comparing it with classical variant (CV) and tall cell variant (TV) of PTC over a stage-matched design. MATERIAL AND METHODS: Pure 100 OV, 71TV and 1219 CV were included in this retrospective cohort study. OV was compared with CV and TV according to independent prognostic parameters. OV was also compared stage by stage with CV and TV for recurrence. RESULTS: Mean age was 46,8 years and male/female ratio 25/75 for OV. The recurrence rates in our study were 16% in OV, 13,5% in CV and 56% in TV. There is a statistically significant difference according to recurrence between stage I and stage IV OV and CV (p=0.023, p=0.03, respectively). There is also a statistically significant difference between stage I and stage IV OV and TV according to recurrence (p=0.001, p=0.024, respectively). OV can be supposed to behave between CV and TV, but very closer to CV. CONCLUSIONS: OV seems to be slightly more aggressive than CV. Despite an inadequate sample size for stage II and III, our findings imply an increased recurrence risk for OV than CV at the advanced stages (stage III and IV) and CV has an unfavorable prognosis than OV at early stages (stage I and II) according to stage-matched model.

Evaluation of hepatocyte function after extracorporeal shock wave lithotripsy with hepatobiliary scintigraphy.

OBJECTIVE: Extra corporeal shock wave lithotripsy is a promising and effective therapy mode in the nonsurgical therapy of gallstones. This prospective study was conducted to investigate the effects of ESWL on hepatocellular function, using quantitative hepatobiliary scintigraphy, serum aminotransferase, alkaline phosphatase (ALP), amylase (AML), and direct and indirect bilirubin levels. METHODS: The study consisted of 22 patients with ultrasonographically documented gallstones. Hepatobiliary scintigraphy was applied to all patients before ESWL and biochemical tests were performed. Scintigraphy and biochemical tests were repeated in 16 patients 24 h, in seven patients 72 h, and in six patients 1 wk after ESWL. The hepatic extraction fraction (HEF) was calculated using deconvolution analysis of scintigraphic data. RESULTS: All patients' pre-ESWL biochemical tests and HEF values were within the normal range. The 24- and 72-h post-ESWL aminotransferase, ALP, and AML levels and HEF values were significantly different from pre-ESWL values (p < 0.05). After 1 wk this difference disappeared. Decreased HEF values were observed in 50% of patients 24 h, in 71.7% of patients 72 h, and in 16.6% of patients 1 wk after ESWL. A direct relationship was also observed between the number of shocks applied and the degree of impairment in HEF values. CONCLUSION: Transient hepatocellular dysfunction, which usually occurs after ESWL, can be demonstrated and monitored using quantitative hepatobiliary scintigraphy.

Saving the zone of stasis in burns with recombinant tissue-type plasminogen activator (r-tPA): an experimental study in rats.

Hypercoagulability 2-3 h following scald injury and vessel thrombosis are well-known complications of burn injury. The present study was designed to determine the effect of recombinant tissue-type plasminogen activator (r-tPA) on vessels thrombosis in zones of stasis postburn. Twenty rats were assigned to experimental and control groups (N:10). After shaving the backs, a 'comb burn' was given bilaterally on the back of the rats 0.5 cm lateral and parallel to the midline by using a brass probe consisting of four rows (10 x 20 mm) and three interspaces (5 x 20 mm). Standardized full-thickness burns of the experimental group were treated with r-tPA via femoral veins 2 h after the burn, while the control group rats were infused the same volume of saline. Interspaces between the rows and vertical space area were evaluated as zone of stasis. The skin blood flow measurements of interspaces revealed a decreased level immediately and 2 h after the burn injury, averaging 11.3 and 9.8 perfusion units, respectively. On day 7, blood flow measurements of interspace and vertical space areas significantly differed between the groups, averaging 11.9 PU in the experimental and 1.8 PU in the control groups (P<0.05). To evaluate perfusion, each rat received 3 mCi of technetium-99m methoxyisobutylisonitrile on the first or seventh day postburn. After 30 min, the entire back skins including the panniculus carnosus muscle layer were dissected away. Gamma camera images revealed that in the experimental group the interspace areas took up 60-90 per cent more radioactivity than the burned areas while in the control group 20-50 per cent more activity was taken up by the interspace area when compared to burned areas. Autoradiography gave the exact borders of the necrotic and survived tissues. The percentage of live interspace and vertical space areas in the experimental group was 87.8 per cent on day 7, while it was 31.8 per cent in the control group (P<0.05). Dry/wet ratios did not reveal any significant difference at 24 h postburn. These results confirm that treatment with this selective fibrinolytic agent (r-tPA) after burn injury would have some benefits on saving the zone of stasis in burns.

The visualization of granulomatous disease with somatostatin receptor scintigraphy.

In-111 labeled pentetreotide scintigraphy was applied to three patients with proven granulomatous disease (two with sarcoidosis, one with tuberculosis). All revealed accumulation of In-111 labeled pentetreotide in the granulomatous lesions, which was considered to be due to the presence of activated lymphocytes in these regions. This method may be of value in assessing the activity and extent of sarcoidosis and tuberculosis.

Value of dobutamine technetium-99m-sestamibi SPECT and echocardiography in the detection of coronary artery disease compared with coronary angiography.

The value of dobutamine echocardiography and 99mTc-sestamibi SPECT imaging was evaluated as a noninvasive diagnostic method for assessing coronary artery disease (CAD). Twenty-seven patients who underwent coronary angiography were submitted to two separate injections of 99mTc-sestamibi, one under control conditions and the other after reaching a peak dobutamine infusion rate. Simultaneous ECG and echocardiographic monitoring was also performed during stepwise dobutamine infusion. Whereas the overall sensitivity and specificity of dobutamine sestamibi SPECT imaging were 94% and 88%, these values for dobutamine ECG and echocardiography were 61%, 55% and 84%, 88%, respectively. When dobutamine echocardiography and 99mTc-sestamibi SPECT imaging were evaluated together, the diagnostic accuracy reaches almost 100%. Dobutamine echocardiography is of value in determining ischemic threshold earlier than clinical symptoms and allows simultaneous evaluation of ventricular performance and contractile function associated with perfusion abnormalities on 99,Tc-sestamibi SPECT imaging. Our experience shows that 99mTc-sestamibi SPECT imaging, when combined with dobutamine echocardiography, is a safe, practical, well tolerated method with high diagnostic accuracy for the evaluation of CAD.

Dobutamine stress radionuclide ventriculography for the detection of coronary artery disease.

Thirty patients were prospectively studied to assess the value of radionuclide ventriculography (RNV) during step-wise dobutamine infusion for the detection of coronary artery disease (CAD). Radionuclide ventriculography was performed under basal conditions and during dobutamine infusion at each 10 micrograms kg-1 min-1 dose increment from 10 to a maximum of 40 micrograms kg-1 min-1. The test response was considered positive if the ejection fraction (EF) decreased by more than 5% or if segmental contraction abnormalities developed. Dobutamine stress testing was well tolerated, no complications and no significant arrhythmia were observed. In nine of 11 patients without CAD, EF increased more than 5% of the rest value and the left ventricular wall motion was normal in 10 of them during dobutamine infusion (specificity 91%). In 18 of 19 patients with CAD, new wall motion abnormalities (WMA) were identified in segments corresponding to the arterial lesions diagnosed by angiography (sensitivity 94%). Ejection fraction response was significantly different in normal subjects and in patients with CAD: 11 +/- 5.9% versus 1.9 +/- 9.5% (P < 0.01). However, abnormal EF response was found in seven of 19 CAD patients and development of new WMA was found to be a more sensitive and specific parameter than EF response for dobutamine RNV. It is concluded that dobutamine RNV is an accurate, widely available and cost-effective test for detecting CAD, especially in patients unable to exercise.

Visualization of bladder diverticulum during Tc-99m DTPA renal scintigraphy.

An eight-year-old boy with recurrent urinary infection underwent Tc-99m DTPA renal scintigraphy for the evaluation of renal function. Stasis of the tracer was observed in the pelvocalyceal systems of both kidneys. Intravenous diuretic was administered to evaluate a possible mechanical obstruction. During the course of the study, a well-defined, round area of activity extended from the bladder which was subsequently confirmed to be a diverticulum on voiding cystourethrogram and at surgery.

Role of bone scanning in the management of non-united fractures: a clinical study.

Technetium-99m methylene diphosphonate (99mTc-MDP) bone scintigraphy was performed in 45 patients (42 male and 3 female) with established non-united fractures to predict the healing response to pulsing electromagnetic field stimulation therapy. The bone scans revealed 3 different scintigraphic patterns. The most frequent pattern was an increased uniform uptake of the tracer at the non-union site (group 1). The second pattern was increased activity at the bone ends with a photon-deficient area between the fracture sites (group 2a) or a generalized decrease in the radionuclide concentration in the region of bone fragments (group 2b). When the scintigraphic pattern did not fit either of the two patterns or when the presence of the cold area between the bone fragments could not be judged with certainty, it was called indeterminate (group 3). All patients underwent pulsing electromagnetic field stimulation. The healing rate was 87.5% and 42.8% in group 1 and group 3 patients, respectively. None of the group 2 patients had any evidence of healing, and they all underwent surgical exploration, revealing complicated non-unions. We conclude that 99mTc bone scintigraphy is a useful tool in determining complicated non-unions and selecting the proper therapy mode.