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Biomedical subjects

M Lorberboym

Publications and source records attributed to M Lorberboym.

At least 37 records · Page 2Linked to original sources
PubMed1997

False-positive uptake of TI-201 by an intracranial inflammatory pseudotumor.

A 28-year-old man had recurrent episodes of headache, ophthalmoplegia, and ptosis. MR imaging showed a mass within the sphenoid sinus. TI-201 imaging showed intense uptake in the region of the sphenoid sinus and right middle fossa with moderate retention of activity, suggesting the diagnosis of a viable tumor. A biopsy specimen from the sphenoid sinus revealed dense inflammatory infiltrate dominated by plasma cells, consistent with inflammatory pseudotumor. After radiation therapy, the mass showed no significant change on MR imaging, but regressed in size and uptake on the follow-up TI-201 scan. TI-201 may accumulate in nonmalignant inflammatory lesions and could mimic a viable tumor. It is, therefore, suggested that before surgery and histologic diagnosis, any abnormal intracranial accumulation of TI-201 should be interpreted with caution.

Adult↗
PubMed1997

Scintigraphic evaluation of Tc-99m-low-density lipoprotein (LDL) distribution in patients with Gaucher disease.

Gaucher disease (GD) is frequently associated with reduced plasma levels of low density lipoproteins, presumably due to increased catabolism of LDL. The purpose of this study was to determine the distribution of Tc-99m LDL (Tc-LDL) in Gaucher patients, and compare the findings to bone marrow distribution. Four patients with non-neuropathic Gaucher disease (type 1) underwent baseline whole body imaging at 4 and 24 h after injection of dialyzed autologous LDL labeled with 10-20 mCi Tc-99m-pertechnetate. Three of the four patients were treated with macrophage-targeted alglucerase (Ceredase). The LDL studies were compared to concurrent bone marrow scans performed with 10 mCi Tc-99m sulfur colloid (Tc-SC). Follow-up Tc-LDL and Tc-SC scans were obtained 12-14 months later. Tc-LDL activity was abnormally increased in the spleen and long bones of the upper and lower extremities. Liver activity was also increased. Prominent blood pool activity 4 h after injection mostly cleared on the 24-hour images. The distribution of Tc-SC was congruent with Tc-LDL activity. All patients had mild-to-moderate hepatomegaly and peripheral bone marrow expansion. One patient had been previously splenectomized and the remaining three had moderate-to-severe splenomegaly. Two of the three treated patients showed regression of peripheral bone marrow activity with therapy, along with a comparable decrease in Tc-LDL uptake. Our study with Tc-LDL and Tc-SC suggests that in patients with Gaucher disease native LDL is taken up by the reticuloendothelial system (RES) of the spleen and bone marrow in addition to increased uptake by the liver. This abnormal uptake (presumably by macrophages of the RES) may account for accelerated LDL catabolism and reduced plasma levels of LDL. Serial LDL studies can be performed, allowing for longitudinal follow-up after drug or enzyme therapies.

Adult↗
PubMed1997

The role of thallium-201 uptake and retention in intracranial tumors after radiotherapy.

UNLABELLED: This study prospectively assessed the diagnostic accuracy and prognostic value of 201TI uptake and retention in primary and metastatic intracranial tumors treated by conventional radiotherapy and/or radiosurgery. METHODS: An initial 201TI study (early and delayed images), was obtained in 60 postsurgical patients, 6-12 wk after radiotherapy or radiosurgery. Repeat imaging was performed as clinically warranted. Tumor-to-background count ratios and a retention index (RI) were calculated for all lesions. RESULTS: Abnormally increased 201TI uptake was observed in 40 of 60 patients. In all patients with positive results, the diagnosis of residual tumor was confirmed at biopsy or by clinical follow-up. In 20 of 60 patients, no abnormal 201TI uptake was observed, despite findings on CT and/or MRI scans that were suspicious for tumor. Ten of the negative 201TI studies were confirmed as true-negatives by the clinical course and by resolution of CT/MRI abnormalities. The remaining 10 negative SPECT studies ultimately proved to be false-negatives: six of these patients had lesions < 1 cm in maximum diameter, one patient had a large metastatic choriocarcinoma; and three patients had low-grade astrocytomas > 2 cm in minimum diameter. Tumor-to-background ratio of 201TI uptake did not distinguish between tumor type, or predict clinical outcome. The RI of 201TI was significantly higher for metastatic melanoma than for other tumor metastases. It demonstrated reasonably good correlation with clinical outcome: 6/7 patients with eventual tumor regression showed a decrease in RI on follow-up examination, and 4/5 patients with eventual tumor progression had an increase in RI. CONCLUSION: Thallium-201 brain SPECT appears to be a useful noninvasive imaging technique in patients irradiated for intracranial tumors. Thallium-201 scintigraphy has very high specificity (100% in this cohort) for detecting viable residual tumor. False-negative findings may occur. Quantitative analysis of 201TI uptake has limited diagnostic and prognostic significance, but changes in 201TI retention after radiation therapy seems to have prognostic value.

Adolescent↗
PubMed1997

Scintigraphic monitoring of reticuloendothelial system in patients with type 1 Gaucher disease on enzyme replacement therapy.

UNLABELLED: The purpose of this study was to define the scintigraphic pattern of marrow replacement and changes in reticuloendothelial activity after enzyme replacement therapy in patients with Gaucher disease. METHODS: Forty patients underwent baseline whole-body imaging with 99mTc-sulfur colloid and evaluation of liver and spleen volume with CT or magnetic resonance imaging. Thirty-seven of the 40 patients were treated with enzyme replacement. Therapeutic responses of central and peripheral bone marrow and the changes in pulmonary uptake of 99mTc-sulfur colloid were assessed visually at 1-4 yr after the start of therapy. Changes in liver and spleen volumes were analyzed quantitatively. The initial pattern of marrow involvement was correlated with disease severity (based on baseline blood counts and liver and spleen volumes). RESULTS: Baseline studies revealed that 38 of 40 (95%) and 28 of 40 (70%) of the patients in this study had abnormal peripheral and central marrow activity, respectively. Twenty of 24 evaluable patients (83.3%) on therapy showed regression of peripheral bone marrow activity to a more proximal location in the lower extremities, increased ratio of pelvic/proximal femoral activity to distal activity or both. Fourteen of 19 treated patients (73.7%) with abnormal initial central marrow activity showed detectable improvement in central bone marrow activity as a result of therapy. In patients with initial lung uptake of 99mTc-sulfur colloid, 91% showed complete resolution of the uptake after therapy. These changes in colloid uptake and distribution were associated with significant reductions in liver and spleen volumes and improvements in blood counts. CONCLUSION: Most patients with Gaucher disease demonstrate increased central bone marrow activity and regression of activity in peripheral bone marrow with enzyme replacement therapy. Additionally, the abnormal phagocytic pulmonary activity observed before therapy in many of the patients resolves.

Adult↗
PubMed1997

Adrenal glands imaging with indium-111-DTPA-D-Phe1-octreotide following ACTH therapy.

Somatostatin receptors have been identified in a variety of neuroendocrine tumors and activated leukocytes. A high density of somatostatin receptors is also present in most intestinal intramural veins of patients with inflammatory bowel disease. We present a case of a 25-yr-old female with severe Crohn's disease unresponsive to medical therapy, including adrenocorticotropic hormone (ACTH) administration. The patient underwent (111)In-DTPA octreotide scintigraphy to evaluate the potential role of somatostatin receptor imaging in inflammatory bowel disease. Despite the lack of significant somatostatin receptors in the affected bowel, an unexpected prominent activity of (111)In-DTPA octreotide was noted in the adrenal glands on the SPECT images, presumably resulting from excessive stimulation by ACTH. The expression of somatostatin receptors in the stimulated adrenals may be used to image other adrenal pathologies and could potentially indicate response to therapy.

Adrenal Glands↗
PubMed1996

Regression of skeletal changes in type 1 Gaucher disease with enzyme replacement therapy.

A 9-year-old patient presented with an acute onset of pain of the right femur showing destructive changes with periosteal elevation mimicking osteomyelitis. Technetium-99m sulfur colloid (99mTc SC) marrow scan revealed lack of uptake in the right femoral head and the entire shaft of the right femur. Eight months following enzyme replacement therapy, radiography showed almost complete reconstitution of the femoral shaft, and 99mTc SC marrow scan uptake returned to normal.

Bone Marrow↗
PubMed1996

Transient false-positive hepatobiliary scan associated with ceftriaxone therapy.

Drug related false-positive hepatobiliary imaging is uncommon. The authors present a case of a 54-year-old woman who was treated with intravenous ceftriaxone for bacterial meningitis. Symptoms of acute cholecystitis subsequently developed and a sonogram revealed a gallstone. A Tc-99m DISIDA hepatobiliary study was positive for cystic duct obstruction. After discontinuation of ceftriaxone, the patient's clinical condition improved and, 2 weeks later, a repeat hepatobiliary scan was normal. High doses of ceftriaxone and prolonged administration may lead to formation of pseudocholelithiasis and signs of acute cholecystitis. Although this condition is usually benign and reversible, discontinuation of the drug is warranted when symptoms of acute cholecystitis are accompanied by a positive hepatobiliary scan.

Ceftriaxone↗
PubMed1996

Brain perfusion imaging during preoperative temporary balloon occlusion of the internal carotid artery.

UNLABELLED: The main objective of this study was to assess whether 99mTc-HMPAO brain SPECT imaging can identify patients at high risk of developing an infarct following permanent carotid occlusion in the course of brain surgery. METHODS: Test balloon occlusion of the internal carotid artery was performed in 44 patients with a variety of head and neck tumors or aneurysms. Technetium-99m-HMPAO was injected intravenously while the balloon was initiated and a SPECT study was obtained 30 min later. Follow-up CT scans were obtained routinely for all patients at 2 wk and 1 mo following surgery, or earlier when necessary. Thirty patients and five normal volunteers had semiquantitative analysis of cerebral perfusion. RESULTS: Twenty-six patients demonstrated ipsilateral perfusion abnormalities during trial occlusion. Eight patients in this group underwent bypass grafting prior to sacrifice of the artery: two resulting in infarcts. Eighteen patients had symmetric cerebral perfusion during occlusion and four of these patients underwent permanent therapeutic carotid occlusion; three patients had subsequent infarcts and the fourth patient had an impending stroke. CONCLUSION: Patients with symmetric cerebral perfusion measured by 99mTc-HMPAO SPECT may still have a high long-term complication rate following carotid sacrifice. The scan findings in these patients were not predictive of the outcome. Patients with asymmetric cerebral perfusion had alternative therapeutic approach to carotid sacrifice and most of them had good surgical outcomes.

Brain↗
PubMed1996

Reversible cerebral perfusion abnormalities associated with cyclosporine therapy in orthotopic liver transplantation.

A 60-yr-old woman experienced several episodes of generalized seizures following 2 wk of immunosuppressive therapy with cyclosporine for orthotopic liver transplantation. CT showed low density in the white matter of the parieto-occipital lobes. A 99mTc-HMPAO brain SPECT showed diminished perfusion in the parieto-occipital cortex bilaterally. Although the cyclosporine was discontinued, the patient's neurologic status initially worsened and then improved over the next several days. Repeat perfusion brain SPECT showed resolution of most of the perfusion abnormalities, while repeat CT showed persistent white matter changes in the parieto-occipital lobes. We report the presence of reversible cortical perfusion abnormalities in conjunction with cyclosporine therapy. The findings suggest that perfusion brain SPECT may be a sensitive monitor of cyclosporine-induced neurotoxicity.

Brain↗
PubMed1996

Thallium-201 and iodine-131 scintigraphy in differentiated thyroid carcinoma.

UNLABELLED: The purpose of this study was to determine the concordance and discordance between diagnostic 131I and 201TI whole-body scintigraphy in patients with differentiated carcinoma of the thyroid. METHODS: Following thyroidectomy for differentiated thyroid carcinoma, 50 patients underwent whole-body 131I and 201TI scanning (60 pairs of scans in total). Fifteen pairs of studies were obtained before ablative therapy, 30 pairs after ablative therapy and 15 pairs after 131I therapy for metastatic disease. Serum thyroglobulin levels were concurrently determined by radioimmunoassay. RESULTS: Thirty-six 131I whole-body scans (in 34 patients) showed residual uptake in the neck, but only six (17%) of the corresponding whole-body thallium studies had detectable uptake in the neck. Fourteen 131I scans (in nine patients) identified multiple metastatic lesions, whereas the thallium scans were interpreted as either negative, nonspecific or showing fewer lesions. In four study pairs, the thallium scans showed solitary lesions that were not detected by the corresponding radioiodine scans. In 16 scans, the thallium studies gave false-positive results. CONCLUSION: Iodine-131 scintigraphy for differentiated thyroid carcinoma is more sensitive and more specific than 201TI scintigraphy for detection of distant metastases and residual activity in the neck following thyroidectomy.

Adenocarcinoma, Follicular↗
PubMed1996

Accelerated thyrotoxicosis induced by iodinated contrast media in metastatic differentiated thyroid carcinoma.

A 67-yr-old woman who underwent total thyroidectomy 32 yr ago developed accelerated hyperthyroidism after injection of iodinated contrast media to evaluate a left hemipelvis mass. The patient was managed with propylthiouracil, beta-blockers and digoxin. Whole-body 201TI and 131I scans demonstrated a functioning metastasis in the left hemipelvis where biopsy revealed a well differentiated follicular thyroid carcinoma. Palliative external beam radiotherapy was administered. The patient then received radioiodine treatment with granulocyte colony-stimulating factor to minimize bone marrow toxicity. Clinically significant thyrotoxicosis occurring in metastatic thyroid carcinoma is rare and results from abnormal ectopic thyroidal tissue iodine metabolism. Iodide-containing medications and contrast media should be avoided in patients with functioning thyroid metastases to prevent abrupt increases in circulating thyroid hormone levels.

Adenocarcinoma, Follicular↗
PubMed1996

Rapid differential diagnosis of cerebral toxoplasmosis and primary central nervous system lymphoma by thallium-201 SPECT.

UNLABELLED: This study sought to assess whether 201Tl brain SPECT can significantly reduce the time required for the differential diagnosis of primary central nervous system (CNS) lymphoma and cerebral toxoplasmosis in patients with AIDS. METHODS: Eighteen patients who presented with focal lesions on CT or MRI, or both, underwent 201Tl brain SPECT shortly after admission and before a CT-guided stereotactic brain biopsy. Early and delayed 201Tl uptake ratios were obtained for patients with positive 201Tl study results, and the retention index of 201Tl was calculated. RESULTS: Ten patients had 11 foci of significantly increased 201Tl uptake in regions of corresponding CT/MRI lesions. Five of these patients had biopsy-proven lymphomas, one of them in two separate foci. Another patient was found to have metastatic adenocarcinoma. Three patients had a clinical course and response to radiation therapy consistent with lymphoma, and study results in another patient were considered falsely positive. Of nine patients with no 201Tl uptake in regions of CT/MRI lesions, two had biopsy findings consistent with a benign etiology, and the other seven improved clinically on antitoxoplasmosis medications alone. The overall sensitivity of 201Tl brain SPECT was 100%, and specificity was 90%. The 201Tl retention index in patients with lymphomas was significantly higher than that in patients with adenocarcinomas and nonmalignant lesions (1.35 +/- 0.16 versus 0.24 and 0.56, respectively). CONCLUSION: Thallium-201 brain SPECT is a sensitive and specific method for rapid differential diagnosis of CNS lymphoma and toxoplasmosis in patients with AIDS. The 201Tl retention index is useful in differentiating CNS lymphomas from other malignant and nonmalignant pathologies.

AIDS-Related Opportunistic Infections↗
PubMed1995

A prospective evaluation of thallium-201 single photon emission computerized tomography for brain tumor burden.

PURPOSE: The follow-up of patients with malignant brain tumors after surgery, radiation, and/or chemotherapy has been inadequate for evaluating brain tumor burden using computerized tomography (CT) or magnetic resonance imaging (MRI). Thallium-201 has been shown to concentrate in viable tumor, and Tl-201 single photon emission computerized tomography (SPECT) imaging can identify tumor burden more accurately than CT. METHODS AND MATERIALS: Thirty-one patients with glioblastoma and three patients with low grade astrocytoma were studied with Tl-201 SPECT. Histololgic diagnosis was obtained in all patients by biopsy and all patients had CT scans within 2 weeks of the SPECT study. Seventeen patients were followed with one or more SPECT and CT evaluations. RESULTS: Single photon emission computerized tomography studies, after surgery, radiotherapy, and/or chemotherapy, were more accurate than CT in identifying progression or regression of disease. Twenty-three patients had evidence of disease and 11 patients had no evidence of recurrent disease in the initial Tl-201 SPECT study following therapy. Computerized tomography identified 20 of the 23 patients with disease and 6 of 11 patients with no recurrent disease. Follow-up with Tl-201 SPECT in 17 patients suggested progression of disease in 9 patients, while CT showed progression in only 3 patients. Clinical examinations and repeat CT studies confirmed the accuracy of Tl-201 SPECT images. CONCLUSION: We found Tl-201 SPECT more accurate than CT scans in a prospective evaluation of 34 patients with brain tumor. Follow-up studies with both Tl-201 SPECT and CT imaging in 17 patients demonstrated that SPECT was more reliable than CT in identifying progression, improvement, or no change in brain tumor burden.

Adult↗
PubMed1995

Predictive value of balloon test occlusion of the internal carotid artery.

Balloon test occlusion (BTO) of the internal carotid artery (ICA) is used in conjunction with single-photon emission computed tomography (SPECT) imaging to assess the cerebrovascular collateral reserve prior to surgical manipulation of the artery. The present report reviews 56 consecutive patients with tumors or vascular lesions at the base of the skull who underwent BTO and subsequent treatment on that basis within a 3-year period. Four patients underwent carotid sacrifice, since they tolerated the BTO and had normal SPECT imaging. Postoperatively, one patient had patchy infarcts in the frontal lobe, another a middle cerebral artery territory infarction, a third had a lacunar infarct, and the fourth had an impending stroke and was treated with an emergent revascularization procedure. There were 15 patients who underwent saphenous vein bypass grafting, of these there were three graft occlusions, one of which resulted in an infarction. There were two other infarctions due to technical difficulties, one being related to the revascularization procedure. Based on these results, we suggest that passing BTO with a normal SPECT study does not necessarily indicate that the patient is immune to stroke following carotid sacrifice. Revascularization should be considered, when ICA sacrifice is deemed necessary to treat the pathologic condition adequately, to minimize the likelihood of a stroke.

Journal Article↗
PubMed1995

Imaging of multiple bilateral parotid gland oncocytomas.

Oncocytoma of the salivary glands is a rare tumor that usually follows a benign course and, in most cases, can be cured by surgical resection. The authors report a rare case of multiple bilateral parotid oncocytomas that presented clinically with two palpable parotid masses. Both CT and MRI scans demonstrated multiple masses in each parotid gland. The tumors exhibited intense uptake and prolonged retention of Tc-99m pertechnetate. The diagnosis was confirmed by fine needle aspiration. Sialoscintigraphy is a simple and noninvasive procedure that can usually separate benign entities like Warthin tumor and oncocytoma of the salivary glands from malignant tumors, and significantly affect the course of treatment.

Adenoma, Oxyphilic↗
PubMed1995

Avid uptake of technetium-99m-HMPAO by an intracranial plasmacytoma during carotid balloon test occlusion.

A 56-yr-old woman was evaluated for removal of a tumor at the base of the skull. A test to determine the risk of carotid artery sacrifice was performed prior to surgery using carotid balloon occlusion of the left internal carotid artery and 99mTc-HMPAO perfusion scintigraphy during the occlusion. An unusual intense focus of increased uptake was seen at the site of the primary tumor in the left cavernous sinus. The tumor, found to be plasmacytoma at surgery, demonstrated only mild washout from 30 min to 2 hr after administration of 99mTc-HMPAO, with a tumor-to-cerebellum ratio of 1.6 and 1.5, respectively, and a tumor-to-contralateral cranial ratio of 2.5 and 2.4, respectively. Intracranial plasmacytoma shows good response to radiation therapy, and the differentiation of this tumor from other neoplasms is pertinent to the mode of treatment and surgical approach. Technetium-99m-HMPAO SPECT imaging may be a useful tool in distinguishing these tumors from other neoplasms at the base of the skull.

Brain Neoplasms↗