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Biomedical subjects

S T Zwas

Publications and source records attributed to S T Zwas.

At least 37 records · Page 2Linked to original sources

Detection efficiency of colorectal carcinoma recurrence using technetium pertechnetate-anti-carcinoembryonic antigen monoclonal antibody BW 431/26.

BACKGROUND: A new anti-carcinoembryonic antigen (CEA) antibody, BW 431/26 (Scintimun, Behring-Werke, Marburg, Germany), labeled with technetium pertechnetate (Tc-99m), is an intact immunoglobulin G1 monoclonal antibody that has been used to image colorectal cancer (CRC). This report is part of a prospective multicenter clinical trial initiated by the International Atomic Energy Agency to evaluate the role of this antibody in radioimmunoimaging of patients with suspected disease recurrence. METHODS: A group of 31 consecutive patients underwent radioimmunoimaging with Tc-99m-BW 431/26 after resection of their primary CRC. Patient referral was based on either a persistent rise in serum CEA levels of unknown origin and/or questionable findings by other imaging studies. Whole-body planar scans and single photon emission computed tomography scans of selected body regions (e.g., chest, abdomen) were performed up to 24 hours after the intravenous antibody injection. Pathologic antibody concentration localizations by radioimmunoimaging were correlated with surgical, clinical, and other imaging modality findings to validate the accuracy of radioimmunoimaging in detecting CRC recurrence. RESULTS: A total of 75 detected tumoral lesions was evaluated: 26 of 75 were of known origin (36%), and 49 of 75 were of unknown origin (65%). There were four true-negative lesions, one false-negative lesion, and no false-positive lesions; all others were true-positive lesions. Sensitivity was 96.8%, specificity 100%, and accuracy 98.6%. The study was easy to perform, without untoward side effects on patients after antibody administration. CONCLUSIONS: Anti-CEA antibody radioimmunoimaging is a highly reliable diagnostic procedure in detecting CRC recurrence and is useful especially for the diagnosis of patients with rising CEA blood levels of unknown origin, thereby significantly affecting patient management. Radioimmunoimaging should become part of the diagnostic workup of patients suspected of having CRC recurrence.

Aged↗

The combined use of classified bone and gallium scans in the management of frontal sinusitis.

Bone and gallium scans of the sinus regions were performed in 32 patients presenting with frontal sinusitis. Bone scans, classified according to 99Tcm-methylenediphosphonate (MDP) distribution patterns indicated both active and resolving sinusitis as well as surgically related bone trauma. Gallium scan uptake intensity correlated well, however, with final outcome and differentiated between active and resolving sinusitis, more specifically than corresponding bone scans. Thus combined studies appear to have a significant role in the diagnosis and management of patients suspected for frontal sinusitis.

Adult↗

Postburn peroneal nerve palsy--a report of two consecutive cases.

We report two patients suffering from mixed deep partial and full skin thickness flame burns covering 45 and 95 per cent of the total body surface area respectively. These patients, following sepsis and multisystem failure, developed unilateral peroneal nerve palsy. The possible aetiology of isolated injury to the peroneal nerve in burned and critically ill trauma patients is discussed.

Adult↗

Occult aortic arch mycotic aneurysm diagnosed by radiogallium scintigraphy.

Aortic arch mycotic aneurysm, an uncommon cause of sepsis, carries a grave prognosis. Clinical presentations as well as laboratory and radiologic examinations may be noncontributory and often misleading. In a patient with a fever of unknown origin, only the radiogallium study could enable an accurate diagnosis and pinpoint the anatomic localization of the mycotic aneurysm as the cause of fever.

Aneurysm, Infected↗

The use of radioiodinated toluidine blue for preoperative localization of parathyroid pathology.

The efficiency of preoperative radioactive toluidine blue (RTB) scintigraphy for the localization of parathyroid pathology was evaluated prospectively in 69 patients (age range, 15 to 81 years; mean, 56 years) with primary hyperparathyroidism. Four patients have previously undergone negative exploratory surgery. Patients underwent preoperative dual radionuclide parathyroid-RTB/technetium 99m (Tc 99m)-thyroid scintigraphies with a computer-interfaced gamma-camera with a pinhole collimator. Computer-acquired scintigraphic data were analyzed for parathyroid localizations by an RTB-parathyroid/thyroid superposition technique. At surgery, parathyroid adenomas were found in 64 patients (single adenomas in 60 patients; two adenomas in four patients), nine of these adenomas were mediastinal. Four patients had parathyroid hyperplasia. One patient had no parathyroid pathology (negative exploratory surgery). Correlation between the surgical-pathologic findings and the scintigraphic RTB localization studies disclosed a sensitivity of 87%, with a specificity of 94%, and an overall accuracy of 92%. The routine use of preoperative scintigraphic parathyroid-RTB/Tc 99m-thyroid localization has proved to be highly effective, enabling detection of small hyperfunctioning parathyroid glands in normal and ectopic locations in a wide range of weights. In this series a success rate of 98% was achieved on initial and reexploratory surgery for primary hyperparathyroidism.

Adenoma↗

Isolated ectopic lung uptake of technetium 99m methylene diphosphonate on bone scintigraphy in primary amyloidosis.

Pulmonary deposition of technetium 99m methylene diphosphonate was found on a bone scan of a patient with undiagnosed primary AL amyloidosis. Unusual clinical manifestations during the course of the disease led to a post-mortem diagnosis. The mechanisms for pulmonary and other ectopic soft tissue bone scan tracer depositions, as well as their significance in the diagnosis of amyloidosis, are discussed.

Aged↗

Mucociliary clearance from central airways in patients with excessive sputum production with and without primary ciliary dyskinesia.

Studies of mucociliary clearance were made on 17 patients with bronchiectasis and excessive sputum production. Tracheal mucus velocity was measured. Five patients with primary ciliary dysfunction and 12 who had no clinical evidence of this defect were studied. The mean (+/- SD) tracheal mucus velocity of the five patients with proved or presumptive primary ciliary dysfunction was 2.9 +/- 0.2 mm per minute and for the 12 patients without ciliary dysfunction, 7.9 +/- 1.4 mm per minute. (The previously determined rate for normals was 4.7 +/- 1.3 mm per minute.) In four of five patients with ciliary dysfunction, CBF was below 7.5 Hz while in the one patient of the 12 without ciliary dysfunction CBF was at the lower limit of normal values. Thus, mucociliary clearance responds to load, depends partly on CBF, and has a built-in control system and the means for compensating for ciliary dysfunction.

Adolescent↗

Scintigraphic presentation of hip joint synovial chondromatosis.

A case of hip joint synovial chondromatosis with an unusual scintigraphic pattern is described. This pattern was suggestive of a hip joint destructive reactive articular process or late manifestations of avascular necrosis of the femoral head. Concurrent radiographs were normal, as were laboratory investigations. Follow-up radiographs six months later showed radiolucencies and erosive bone changes in the diseased joint. Surgical and histopathological findings revealed well developed hip synovial chondromatosis (HSC) with thickened synovium and large, loose, cartilaginous bodies occupying and widening the tightened joint space, with destructive secondary juxta articular pressure and bone erosions. This and other scintigraphic patterns in HSC, and the differential diagnosis of the findings in patients with painful hip presentations are discussed.

Chondroma↗

Graves' disease presenting as pyrexia of unknown origin.

Fever is a common clinical manifestation of inflammatory processes of the thyroid and thyroid crisis. On the other hand, fever alone as a presenting symptom of thyrotoxicosis, without other manifestations, is extremely rare. A female patient is described in whom fever persisted for two months prior to hospitalization, but without clinical symptoms or signs to lead to suspicion of thyroid disease. After exhaustive investigation it was found that the patient was suffering from hyperthyroidism. Fever disappeared gradually on antithyroid therapy, recurred when the drugs were withdrawn for a rechallenge trial, and cleared up again after renewal. Four other cases of persistent fever as a presenting symptom of hyperthyroidism were found on a review of previous publications. Thyrotoxicosis should, therefore, be included in the differential diagnosis of pyrexia of unknown origin.

Female↗

Simplified assessment of arterial graft patency using indium-labelled-platelet scintigraphy.

Arterial grafts were studied with indium-III-labelled platelets in 13 patients (18 graft limbs) in the early post-implication period. Platelet thrombogenic activity was graded into four grades by visual inspection of the images, and scintigraphic criteria of impending graft occlusion were defined. Dacron and polytetrafluoroethylene grafts had similar high thrombogenic activity in comparison with autologous veins. Nine graft studies showed patterns of radioactivity concentration that suggested threatening thrombosis and eight of these eventually occluded. In nine other studies absent to moderate radiolabelled platelet activity was observed and none occluded within a mean follow-up period of 24 months. Prediction of graft occlusion of scintigraphic evaluation using the present simple non-invasive technique is valuable since corrective measures may be instituted earlier and with greater success in the post-operative follow-up period.

Aged↗

Optimizing selection of in vitro tests for diagnosing thyroid disorders.

The optimal utilization of the thyroid related radioimmunoassays T3, T4, and TSH-RIA is derived from analysing the clinical and laboratory data for 974 patients with functional thyroid disorders. A statistical computer analysis of the contribution of each of the three tests, and in combination, to the final diagnoses of hypothyroid, euthyroid, and hyper thyroid states was designed. The best contributing test for hypothyroidism and euthyroidism was TSH-RIA (98.5 and 93%, respectively). T4/T3 + TSH-RIAs were the optimal dual combination for diagnosing euthyroidism (98.0%). For diagnosing hyperthyroidism T4-RIA was the best single test (82.5%) followed by T3 + T4 as an optimal dual combination (95%). Using all three tests was of no significant additional value over dual combinations. It is concluded that the work and cost of randomly performing three tests routinely is not justified without clinical basis. An algorithm is proposed to guide thyroid studies based on computer analyses of the above-mentioned single or dual-test combinations to establish accurate diagnosis at the lowest laboratory cost.

Female↗

Sarcoidosis versus foreign-body granulomas.

A 42-year-old man developed a papulonodular exanthema 10 years following an injury from a shell explosion. The differential diagnosis between sarcoid-like, foreign-body granulomas and Boeck's sarcoid was inconclusive by histology, but x-ray spectroanalytic examination revealed silicon particles within the epitheloid cell granulomas.

Adult↗

Preoperative parathyroid localization by superimposed iodine-131 toluidine blue and technetium-99m pertechnetate imaging.

A new parathyroid scintigraphic localization study by a dual radioisotope technique using radioiodinated toluidine blue (RTB) for the parathyroids and 99mTc for thyroid imaging is presented. A simple RTB labeling procedure achieving 99% tagging of the 131I-TB was used. The RTB was found to be a highly specific parathyroid radiotracer, consequently enabling superimposition of the delineated thyroid gland over the RTB avid parathyroid foci without a need for subtraction of the thyroid or vascular background. Forty-six patients with primary hyperparathyroidism underwent scintigraphic study prior to cervical (41 patients) or mediastinal (5 patients) exploration and 67 pathological parathyroid glands (34 adenomas and 33 hyperplasias) were excised. On follow-up, serum calcium level returned to normal in all patients. Correlation of the scintigraphic results with the surgical findings disclosed a sensitivity of 93%, with a specificity of 80% and an overall accuracy of 87%. This new simplified and specific RTB scintigraphic method justifies its use as a routine procedure for preoperative parathyroid scintigraphic localization in primary hyperparathyroidism.

Adolescent↗

Interpretation and classification of bone scintigraphic findings in stress fractures.

A new system for classification of stress fractures identified by bone scintigraphy was developed and divided into four grades according to lesion dimension, bone extension, and tracer accumulation. The scintigraphic findings were evaluated for severity of lesions by extent of the visualized bone response, ranging from ill-defined cortical lesions with slightly increased activity (I) to well-defined intramedullary transcortical lesions with intensely increased activity (IV). Bone scintigraphies using [99mTc]MDP were obtained in 310 military recruits suspected of having stress fractures. In 235 patients, 391 stress fractures were diagnosed. Forty percent of the lesions were asymptomatic. Most of the lesions were in the tibiae (72%), and 87% of the patients had one or two lesions, while 13% had three to five lesions. Eighty-five percent of the lesions were classified as mild and showed early and more complete resolution on follow-up studies after treatment as compared to the severe grades. Furthermore, specific scintigraphic patterns have been introduced for distinguishing inflammatory shin-splints from stress fractures, allowing for their appropriate early treatment. Thus, early recognition of mild stress fracture scintigraphic patterns representing the beginning of pathologic bone response to stress enabled a prompt and effective treatment to prevent progression of lesions, protracted disability, and complications.

Adult↗

Scintigraphic monitoring of mucociliary tracheo-bronchial clearance of technetium-99m macroaggregated albumin aerosol.

A simple method for in vivo monitoring mucociliary tracheo-bronchial clearance is described. Eighteen healthy subjects and 13 patients with various chronic lung diseases were studied by this method. The principle of using an aerosol administration system similar to the system used for routine ventilation lung studies is stressed. Proximal large airway deposition of the radioaerosol was obtained by using relatively large particles (average diameter 2 microM) of [99mTc]MAA aerosol. Monitoring was performed by visual inspection of the tracheo-bronchial cinescintigraphic ascendence of the accumulated radioactive boli and by assessing their rate of clearance via automated computer analysis of the time-activity curves, following the movement of each bolus. The normal mean +/- s.d. clearance rate thus obtained was 4.7 +/- 1.3 mm/min. This rate appears to be more precise as compared with the range of results obtained by other radioisotopic methods. Significantly faster rates, mean 8.2 +/- 1.4 mm/min (p less than 0.001) were obtained in bronchiectatic patients while slower rates (2.8 mm/min) were seen in a patient with ciliary dyskinesia.

Adult↗