In vivo imaging and radioiodine therapy following sodium iodide symporter gene transfer in animal model of intracerebral gliomas.

Radioactive iodide uptake (RAIU) in thyroid follicular epithelial cells, mediated by the sodium iodide symporter (NIS), is the first rate-limiting step in iodide accumulation which provides a mechanism for effective radioiodide treatment for patients with thyroid cancer. We hypothesize that NIS gene transfer to non-thyroid tumor cells will enhance intracellular radioiodide accumulation and result in better tumor control. Here, we performed non-invasive tumor imaging and (131)I therapy studies using rats bearing intracerebral F98 gliomas that have been retrovirally transduced with human NIS. Our results show that: (1) NIS is expressed in the intracerebral F98/NIS gliomas; (2) F98/NIS gliomas can be imaged by (99m)TcO(4) (whose uptake is also mediated by NIS) and (123)I scintigraphy; (3) significant amounts of radioiodide were retained in the tumors at 24 h after (123)I injection; (4) RAIU and NIS expression in the thyroid gland can be reduced by feeding a thyroxine-supplemented diet; and (5) survival time was increased in rats bearing F98/hNIS tumors by (131)I treatment. These studies warrant further investigating tumor imaging and therapeutic strategies based on NIS gene transfer followed by radioiodide administration in a variety of human cancers.

Routine preoperative lymphoscintigraphy is not necessary prior to sentinel node biopsy for breast cancer.

BACKGROUND: This prospective study was performed to ascertain the added benefit of lymphoscintigraphy to a standard method of intraoperative lymphatic mapping and sentinel node biopsy for breast cancer. METHODS: Patients with invasive breast cancer were injected with 99mTc sulfur colloid prior to sentinel node biopsy; preoperative lymphoscintigraphy was then performed in half of the patient population. RESULTS: Sentinel node identification was possible in 45 of 50 patients (90%). All 14 patients (31%) with axillary nodal metastases had at least one histologically positive sentinel node (0% false negative rate). Lymphoscintigraphy revealed sentinel nodes in 17 of the 24 patients (70.8%) imaged. All 17 of these patients had one or more axillary sentinel nodes identified using intraoperative lymphatic mapping. In addition, 5 of 7 patients with a negative preoperative lymphoscintogram had an axillary sentinel lymph node(s) identified intraoperatively. None of the tumors showed drainage to the internal mammary lymph node chain by lymphoscintigraphy despite the fact that there were 5 patients with inner quadrant tumors. There was no significant advantage with respect to sentinel lymph node localization (91.7% versus 88.5%, P = not significant) or false negative rate (0%, both groups, P = not significant) in the group undergoing preoperative lymphoscintigraphy when compared with the patients in whom lymphoscintigraphy was not performed. CONCLUSIONS: Preoperative lymphoscintigraphy adds little additional information to intraoperative lymphatic mapping, and its routine use is not justified.

Lymphoscintigraphy and intraoperative lymphatic mapping of sentinel lymph nodes in melanoma patients.

Identification of sentinel lymph nodes (SLNs) using lymphoscintigraphy, the blue dye technique and intraoperative lymphatic mapping with a gamma-detecting probe has become the standard of care in diagnosing and treating melanoma. Numerous clinical studies have proven the reliability of predicting the histology of remaining lymph nodes in the lymphatic basin from the histologic evaluation of the SLNs. Technical and clinical factors presented in this paper have been shown to increase the accuracy of localization of SLNs. The nuclear medicine technologist shares a vital role in the radiopharmaceutical preparation and administration for preoperative lymphoscintigraphy and intraoperative lymphatic mapping in patients with melanoma.

Metastatic pure papillary thyroid carcinoma presenting as a toxic hot nodule.

In the majority of cases, carcinoma of the thyroid presents as a cold nodule by radioiodine and Tc-99m sodium pertechnetate scintigraphy. Whereas the presence of a hot nodule usually implies a benign entity, it does not provide complete assurance against thyroid malignancy. Presented is a rare case of metastatic pure papillary thyroid carcinoma appearing as a hot nodule on Tc-99m sodium pertechnetate and I-123 sodium iodide scintigraphy. The implications of such a case, its management, and review of the pertinent literature are discussed.

Atypical findings of discordant bone scan and radiographs in transient osteoporosis of the hip: case report and review of the literature.

The authors report atypical findings of discordant bone scans and radiography seen in a patient with transient osteoporosis of the hip (TOH). Presented in the case of a 60-year-old man who had spontaneous onset of left hip pain which worsened for 2 months with weight-bearing on the affected side. Initial and follow-up radiographs of the let hip were normal. Bone scan demonstrated intense uptake of Tc-99m MDP in the affected femoral head and neck, corresponding to characteristics of abnormal signal intensity of TOH or transient bone marrow edema syndrome on MRI. This discordant pattern of bone scan and radiographs has rarely been reported in the literature. Its possible mechanism of causation and clinical implication in TOH, together with a review of the literature, are discussed in this report.

Indium-111-pentetreotide scanning versus conventional imaging techniques for the localization of gastrinoma.

BACKGROUND: The present study evaluates 111In-pentetreotide scanning as a method for detection of gastrinomas. Operative findings serve as the benchmark for comparison of the efficacy of 111In-pentetreotide versus conventional imaging studies. METHODS: Twelve patients (seven female and five male; age, 37 to 80 years) with histologic confirmation of gastrinoma underwent thin section dynamic computed tomography (CT) scanning and 111In-pentetreotide scanning. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 111In-pentetreotide and CT scanning are compared on the basis of tumor size and location. RESULTS: Thirty discrete foci of intrahepatic and extrahepatic tumors were detected at operation. CT scanning detected three of nine pancreaticoduodenal lesions, whereas eight of these nine extrahepatic primary tumors were imaged by 111In-pentetreotide scanning. No false-positive 111In-pentetreotide scans were noted. The sensitivity of CT scanning for detection of metastatic disease was 56% versus 94% for the 111In-pentetreotide scan. Successful CT imaging was highly dependent on tumor size. No tumor smaller than 1 cm was imaged by CT, whereas four of seven lesions greater than 1 cm were imaged by 111In-pentetreotide scintigraphy. The smallest gastrinoma imaged by 111In-pentetreotide scanning was a 4 mm duodenal tumor. CONCLUSIONS: 111In-pentetreotide scanning was superior to CT scanning for localizing gastrinomas. Further studies are required to determine whether 111In-pentetreotide scans will complement or replace traditional imaging methods.

Exercise-induced QRS changes (Athens QRS score) in patients with coronary artery disease: a marker of myocardial ischemia.

Previous studies have shown a good correlation between exercise-induced changes of Q-, R-, and S-waves (Athens QRS score) and the number of the obstructed coronary arteries. The present study was undertaken to test the hypothesis that abnormal Athens QRS score is related to exercise-induced myocardial ischemia. Patients who had exercise radionuclide ventriculography (n = 150) or thallium-201 scintigraphy (n = 124) within 1 month of cardiac catheterization were studied. Athens QRS score was calculated based on the exercise-induced changes of the Q-, R-, and S-waves. Changes in Athens QRS score were compared to the number of obstructed coronary arteries, segmental contraction abnormalities, and exercise-induced myocardial perfusion defects. Athens QRS score and coronary artery disease: The Athens QRS score was decreased as the number of obstructed coronary arteries increased (normal coronary arteries 3.7 mm, confidence interval 1.0 to 3.9, one vessel disease 1.2 mm, two vessel disease -0.6 mm, three vessel disease -1.3 mm, p < 0.001). Athens QRS score and segmental contraction abnormalities: The Athens QRS score decreased as the number of segmental contraction abnormalities increased (no segmental contraction abnormalities 2.5 mm, confidence interval 1.0 to 3.9, one segmental contraction abnormality -0.4 mm, two segmental contraction abnormalities -1.5 mm, three segmental contraction abnormalities -2.6 mm, p < 0.001). Athens QRS score and reversible myocardial perfusion defects: The Athens QRS score was decreased as the number of exercise-induced myocardial perfusion defects increased (no perfusion defect 2.4 mm, confidence interval 0.9 to 3.9, one perfusion defect -0.7 mm, two perfusion defects -2.6 mm, three perfusion defects -3.3 mm, p < 0.001). Abnormal values of the Athens QRS score were better correlated with the number of exercise-induced segmental contraction abnormalities or the myocardial perfusion defects than the number of obstructed coronary arteries (p < 0.001). Exercise-induced changes in Athens QRS score were directly related to the number of obstructed coronary arteries, to exercise-induced segmental contraction abnormalities and to exercise-induced myocardial perfusion defects. However, Athens QRS score changes were more closely related to the number of exercise-induced segmental contraction abnormalities or to the exercise-induced myocardial perfusion defects than to the number of obstructed coronary arteries. The data suggest that exercise-induced QRS changes, Athens QRS score are related to exercise-induced myocardial ischemia.

Somatostatin receptor imaging of neuroendocrine tumors with indium-111 pentetreotide (Octreoscan).

Somatostatin, a naturally occurring 14-amino acid peptide, can be thought of as an anti-growth hormone and functional down-regulator of sensitive tissue. Most neuroendocrine tumors seem to possess somatostatin receptors in sufficient abundance to allow successful scintigraphic imaging with radiolabeled somatostatin congeners. Several of these, including Indium-III-DTPA Pentetreotide (Octreoscan [Mallinckrodt Medical, St. Louis, MO]), which was approved for clinical use by the Food and Drug Administration in June 1994, have been of considerable value in scintigraphically identifying various neuroendocrine tumors. The Octreoscan compares favorably with other imaging modalities. The success of somatostatin receptor imaging in evaluating patients with suspected neuroendocrine tumors, including identifying otherwise radiographically occult lesions, has resulted in ranking somatostatin receptor imaging as the prime imaging procedure in patients with suspected neuroendocrine tumors at The Ohio State University.

Decreased platelet adherence of polymer-coated tantalum stents.

PURPOSE: To compare the acute thrombogenicity of polyurethane-coated stents with that of bare tantalum stents. MATERIALS AND METHODS: Thirty stents (15 coated with polyurethane) were balloon expanded in 8-mm x 80-cm sections of polytetrafluoroethylene grafts (six stents per graft). Under sterile conditions, 8- and 10-F vascular sheaths were placed percutaneously in the femoral artery and vein of a 100-lb (45-kg) swine. Platelets were labeled with indium-111 and reinjected for quantitative assay. The stented grafts were connected to the arterial and venous sheaths to create an ex vivo fistula. Each fistula was opened for 5, 10, 30, 60, or 120 minutes, exposing heparinized blood to fully expanded stents. The fistulas were closed, flushed with saline until clear, and fixed with formalin. Stents were explanted, placed in a radionuclide well counter, and scanned with electron microscopy. RESULTS: Quantitatively, there were considerably fewer platelets on coated versus uncoated stents. At 60 minutes, coated stents averaged 12.93 platelets per 1,000 microns 2 compared with 75.88 platelets per 1,000 microns 2 for bare metallic stents. At 120 minutes, there were 23.22 platelets/1,000 microns 2 versus 102.31 platelets/1,000 microns 2, respectively. Electron microscopy of coated stents demonstrated few scattered platelets at 5, 10, and 30 minutes. There was a uniform layer of platelets at 60 and 120 minutes. Uncoated stents demonstrated random areas of platelet clumping at 5, 10, and 30 minutes. At 60 and 120 minutes, uncoated stents showed extensive layering of platelets and fibrin. CONCLUSION: Polyurethane coating decreases platelet adhesion, relative to bare tantalum, at all time intervals tested.

Exercise-induced QRS prolongation in patients with coronary artery disease: a marker of myocardial ischemia.

The objective of this study was to investigate the effect of myocardial ischemia on the QRS duration in patients with coronary artery disease since acute myocardial ischemia decreases conduction velocity through the ischemic myocardium and may produce QRS prolongation on the surface electrocardiogram. One hundred fifty patients who underwent cardiac catheterization and exercise radionuclide ventriculography within 1 month of each other were studied. Forty patients had normal coronary arteries and 110 had coronary artery disease. QRS duration decreased with exercise in patients with normal coronary arteries (-3.0 msec, confidence limits -6.2 to 0.2), but increased in patients with coronary artery disease; exercise-induced QRS prolongation was directly related to the number of diseased vessels (4.8 msec in patients with one, 7.8 msec in patients with two, and 13.3 msec in patients with three-vessel disease, p < 0.001). Likewise, QRS duration decreased with exercise in patients without exercise-induced segmental contraction abnormalities (-1.8 msec, confidence limits -3.7 to 0.1), but increased in patients with segmental contraction abnormalities (6.7 msec in patients with one, 13.5 msec in patients with two, and 21 msec in patients with three segmental contraction abnormalities, p < 0.0001). Exercise-induced QRS prolongation was better related to the number of segmental contraction abnormalities than to the number of diseased vessels (p < 0.01). It was concluded that exercise produces QRS prolongation in patients with coronary artery disease in direct relation to the number of diseased vessels and to exercise-induced segmental contraction abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Hemodynamic benefits of verapamil after aortic reconstruction.

Because of the high incidence of coronary artery disease (CAD) in patients undergoing aortic surgery, and because myocardial oxygen consumption is proportional to blood pressure x heart rate (HR) (pressure-rate product), it is important to prevent increases in these parameters postoperatively. The effect of verapamil, a calcium channel antagonist, on these parameters was evaluated in 30 patients undergoing abdominal aortic reconstruction. Postoperatively HR increased 27% in 19 patients without CAD and 47% in 11 patients with CAD. Pressure-rate product (blood pressure x HR) increased 17% and 31% in these two groups, respectively. Verapamil was able to reduce postoperative HR by 3% in patients without CAD and by 13% in patients with CAD. Verapamil reduced pressure-rate product 8% and 18%, respectively, in the two groups. These reductions were statistically significant in patients with CAD and occurred without reductions in cardiac output or left ventricular ejection fraction. Thus the postoperative increases in myocardial oxygen demand appeared to be primarily related to increased HR after aortic surgery, and these were reduced by verapamil without impairing blood flow or cardiac function.

Hemodynamic effects of dilevalol in patients with systemic hypertension and left ventricular dysfunction.

Hemodynamic and left ventricular function parameters were measured in patients with mild to moderate hypertension and compromised left ventricular function who were given dilevalol, an antihypertensive agent with selective beta 2-agonism and nonselective beta-antagonist activity. After a 2- to 3-week placebo washout period, 9 patients were given dilevalol titrated upward from 100 to 600 mg twice daily over a 7-week period to achieve a supine diastolic blood pressure of less than 90 mm Hg with a decrease of greater than or equal to 10 mm Hg from baseline. Multigated radionuclide ventriculography and systolic and diastolic time intervals were performed after the pretreatment placebo washout, at the end of 2 weeks' maintenance dosing, and after a 7- to 10-day post-treatment discontinuation and placebo washout period. At an average daily dose of dilevalol, 444 mg, heart rate at rest decreased significantly (p less than 0.01) during treatment and increased during post-treatment placebo. Systolic and diastolic blood pressures at rest decreased significantly (p less than 0.01) during treatment and increased during post-treatment placebo. At maximal exercise, changes in blood pressure and heart rate were significantly blunted (p less than 0.05) during treatment. Ejection fraction at rest increased significantly (p less than 0.01) during treatment, with no significant change occurring during exercise, and decreased during post-treatment placebo. Preejection period decreased significantly during treatment (p less than 0.005) and increased during post-treatment placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Benign histiocytoma (xanthoma) of the rib.

A 64-year-old man was found to have isolated focal rib lesion(s) by radiographs and radionuclide bone scan. A biopsy of one of the lesions located by imaging was done. The histologic diagnosis was sclerosing (ossifying) xanthoma. A literature search disclosed that xanthomatous lesions of bone are only one of the manifestations in hyperlipidemic patients. These benign lesions should be included among the causes of discrete hot rib abnormalities visualized on bone scan.

Computed tomographic and angiographic demonstration of gastroduodenal artery pseudoaneurysm in a pancreatic pseudocyst.

The complementary use of computed tomography and angiography in two patients with bleeding gastroduodenal artery pseudoaneurysm associated with pancreatic pseudocyst is presented.

Lack of visualization of the portal venous tree in cirrhosis of the liver: a computed tomography finding with possible diagnostic significance.

During computed tomography (CT) scanning of the liver, the inferior vena cava can be identified as a separate structure of lesser density adjacent to the caudate lobe in two-thirds of patients without known hepatocellular disease. In patients with alcoholic (portal) cirrhosis of moderate to severe degree, intrahepatic portal veins may not be identified on CT scans, even though their inferior vena cavas can be definitely distinguished from the caudate lobe. Portal cirrhosis causes distortion and obliteration of the portal triads, which is presumably reflected by lack of visualization of intrahepatic portal veins during CT scanning.

Confusing appearance of a dilated jejunal loop.

A case report is presented concerning a patient with a dilated loop of bowel that was misinterpreted on ultrasound examination. Attention is called to this entity as part of the differential diagnosis of an intra-abdominal fluid collection demonstrated by ultrasound.

Potential organ or tumor imaging agents. 16. Fluorinated androstanes and the prostate.

A series of substituted 5alpha-androstan-17beta-ols was synthesized and evaluated for their potential use in the development of a prostate imaging agent. The ability of the synthesized compounds to compete with [3H]-5alpha-dihydrotestosterone for rat prostate androgen receptor protein served as the screening assay. For 3-substituted derivatives, the order of binding to the androgen receptor protein was =O greater than -OH greater than H approximately or equal to F. 3beta-Fluoro-5alpha-androstan-17beta-ol was found to have approximately 5% the androgenic activity of testosterone propionate in the castrated rat. The low biological activity for the 3beta-fluoro derivatives, coupled with the synthetic obstacles associated with introducing fluorine-18, has led us to search for more suitable halo steroids as potential radiodiagnostics.