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Biomedical subjects

W J Shih

Publications and source records attributed to W J Shih.

At least 19 recordsLinked to original sources
PubMed1992

The role of nuclear medicine in oncology.

Nuclear Medicine offers screening methods for oncology such as bone and bone marrow scintigraphy. During the last two decades, special procedures have gained widespread application. This paper is centered around the "tumor-specific" radiopharmaceuticals. In patients with thyroid cancer, I-131 still plays a significant role. Ga-67 still has its indications in lymphoma, while in other diseases Tl-201 chloride is now the agent of choice. Especially in thyroid cancer, Tl-201 has proved to be a reliable tumor imaging radiopharmaceutical. More recently, Tc-99m MIBI was introduced for tumor imaging. Tc-99m HMPAO may also be used for tumor scintigraphy, especially in brain lesions. In addition, I-123 IMP has successfully been used for imaging malignant melanoma. Another promising field of tumor diagnosis is receptor imaging. In neuroblastoma and malignant pheochromocytoma, I-131/123 mIBG is the radiopharmaceutical of choice and may be considered as a receptor imaging agent also. First clinical results with In-111 octreotide show potentials as somatostatin-receptor radiopharmaceutical in insulinoma, islet cell carcinoma, medullary and lung cancer, while I-123 estradiol needs some improvement until it may be recommended as diagnostic tool in breast cancer. Since 1978, radiolabeled poly- or monoclonal tumor antibodies and their fragments have gained widespread application. Especially the Tc-99m 225.28S melanoma antibody, I-131 or Tc-99m CEA and In-111/I-131 labeled OC-125 antibodies have proven to be of clinical significance in melanoma, colorectal and ovarian cancer.

Gallium Radioisotopes↗
PubMed1992

Prostate adenocarcinoma using Gleason scores correlates with prostate-specific antigen and prostate acid phosphatase measurements.

To evaluate a relationship between Gleason scores of histopathology of prostate carcinoma and concurrent serum prostate-specific antigen (PSA) and prostate acid phosphatase (PAP) values, 65 men with prostate carcinoma were studied. These patients' cumulative Gleason scores were obtained by totaling the primary and secondary patterns, resulting in two groups: 42 patients received high (6-10) and 23 received low (2-5) Gleason scores. Serum PSA and PAP values were measured by radioimmunometric assay 1 to 7 days before surgical procedures or biopsy for prostate carcinoma. Mean serum PSA for patients in the high Gleason score group was 134.39 ng/mL (normal range: 0 to 4), and the mean serum PSA for patients in the low Gleason score group was 23.62 ng/mL. Mean serum PAP for patients with high scores was 28.08 ng/mL (normal range: 0 to 5), and the mean serum PAP for patients with low scores was 18.19 ng/mL. Patients with high Gleason scores showed significantly greater elevation of serum PSA than those with low Gleason scores (P = .047), using two samples to test for groups having unequal variants. Prostate acid phosphatase levels of patients with high scores were not significantly higher than the levels in patients with low scores (P = .60). These results indicate that PSA levels but not PAP levels correlate with Gleason scores.

Acid Phosphatase↗
PubMed1992

Urinary extravasation from the kidney of recurrent renal cell carcinoma.

A man presented with recurrent renal cell carcinoma, complicated with acute pyelonephritis, 3 months status post partial nephrectomy. He underwent cystourethroscopy and a bilateral retrograde pyelogram, then was referred for a Tc-99m DTPA renal study; the images showed an initial photon-deficient area of the right kidney being gradually filled-in by radiotracer with further extension laterally, indicating urinary extravasation. 16 days later this area was aspirated, yielding 5 ml of yellowish fluid with clots consistent with necrotic tumor and pus.

Aged↗
PubMed1992

Cholescintigraphic demonstration of transient and functional common bile duct obstruction in a patient with acute pancreatitis.

Cholescintigraphy has proven useful in diagnosis of acute and chronic cholecystitis and evaluation of common bile duct obstruction. Common bile duct obstruction may be due to mechanical obstruction such as impact stone in the common duct or functional obstruction due to sepsis with intra-hepatic cholestasis or acute viral hepatitis. We present a cholescintigram of a patient with acute pancreatitis showing complete common bile duct obstruction.

Acute Disease↗
PubMed1992

Reversible thallium-201 perfusion defects of the septal and inferoapical segments in a patient with incomplete right bundle branch block and normal coronary angiogram.

Possible causes of reversible perfusion defect in exercise-rest 201Tl myocardial images in a patient with a normal coronary artery angiogram include left bundle branch block, coronary spasm, myocardial bridges, hypertrophic cardiomyopathy, mitral valve prolapse, aortic valve disease and anomalous origin of the left coronary artery arising from the pulmonary artery. This case is a report of a 34-yr-old man with incomplete right bundle branch block and angiographically normal coronary arteries who was found to have reversible defects involving septal and inferoapical walls on stress-rest 201Tl-chloride myocardial imaging.

Adult↗
PubMed1991

A note on the analysis of titration studies.

We propose a method to incorporate all types of dropouts in the evaluation of an intervention based on binary data from a titration study. The proposed procedure does not require that the dropouts occur randomly, but instead examines each outcome individually. Our procedure has a built-in penalty factor in the estimation process that determines the amount of penalty on efficacy parameters due to efficacy-related dropouts. We also propose a method to estimate the variances associated with the estimates. The results have use in exploration of a potential dose-response relationship or to answer questions pertinent for phase III studies. We use data from a phase III antihypertension study to illustrate the procedure.

Algorithms↗
PubMed1991

Tc-99m HMPAO diffuse pulmonary uptake demonstrated in cigarette smokers.

Tc-99m HMPAO, a lipophilic radiotracer used as a brain SPECT imaging agent in the diagnosis of strokes and dementias, is normally localized in the brain and the heart and is excreted through the kidneys (50%) and the hepatobiliary system (14% to 30%). There is no pulmonary localization except in the lungs of smokers. To evaluate pulmonary localization of Tc-99m HMPAO in relation to smoking, 23 patients (aged 27 to 76 years) who were referred for brain imaging studies for strokes or dementias also underwent lung imaging studies immediately following the brain imaging. Anterior and/or posterior lung images were obtained 30 to 45 minutes after IV injection of 15 mCi Tc-99m HMPAO. Diffuse pulmonary uptake was graded semiquantitatively: 3+, pulmonary uptake is equal to or higher than hepatic uptake; 2+, pulmonary uptake is less than hepatic uptake but higher than cardiac uptake; 1+, pulmonary uptake is equal to cardiac uptake; 0, pulmonary uptake is less than cardiac uptake. Each patient's smoking history, including duration and daily consumption, was recorded. Four patients' lung images showed 3+ lung uptake; 6 patients, 2+; 1 patient, 1+; and 12 patients, 0 uptake. Eleven patients with lung uptakes of 3+ to 1+ had a history of cigarette smoking. Twelve patients with lung uptake less than cardiac uptake had no smoking history. Pulmonary distribution of Tc-99m HMPAO is usually negligible in the normal lung. Our results indicate that lung uptake correlates significantly (chi-square = 23, d.f. = 1, P = 0.0001) with smoking history.

Adult↗
PubMed1991

Intraventricular photon deficiency in gated cardiac blood pool imaging due to left ventricular metastases from renal cell carcinoma.

Cardiac metastasis can occur with any widely disseminated malignancy, especially from carcinoma of the kidney, stomach, lung, breast, or from melanocarcinoma. Metastasis to the myocardium can protrude from the endocardium into the intraventricular cavity of the left ventricle. We present a case of renal cell carcinoma and left ventricle cavitary metastases, documented by an echocardiogram demonstrated in a cardiac blood pool study as a photon-deficient area in the left ventricle cavity.

Carcinoma, Renal Cell↗
PubMed1991

Prediction of radionuclide bone imaging findings by Gleason histologic grading of prostate carcinoma.

To evaluate a relationship between Gleason scores and Tc-99m HMDP bone imaging findings, data from 48 men (aged 45 to 77; mean, 67) with prostate carcinoma who had a bone imaging study at the time of presentation were reviewed. Cumulative Gleason scores were divided into two groups: high scores (6-10), 32 men; low scores (2-5), 16 men. Of the 32 men with high Gleason scores, 15 tested positive for multiple metastases and 17 tested negative. Tumors of the 16 men with low Gleason scores were negative for metastasis. A chi-square association between Gleason scores and the presence of metastases, either of a superscan pattern or multiple metastases, was 10.9 (1 df, P less than 0.001). The results indicate that a superscan pattern or multiple metastases were found exclusively in the bone images of patients with high histologic grades; bone images negative for metastases were associated with low-grade tumors. We conclude that positive bone imaging for metastases at the initial scan occurs only in patients who have high Gleason scores, that patients with high Gleason scores might or might not have skeletal metastasis, and that skeletal metastasis is not predictable in patients with low Gleason scores.

Adenocarcinoma↗