Search

The phase 1/2a SECURE trial exploring 2 novel SAR-bisPSMA Targeted Copper Theranostics (TCT) in patients with metastatic castration-resistant prostate cancer (mCRPC) has completed recruitment for the initial dosimetry phase, according [...]

Growth of radioactive and fluorescent kinase assays with relation to drug discovery is presented.

HISTORY An 83-year-old man seen just after he fell when trying to step over the side rail of his bed. Had been admitted to the nursing home 1 day earlier [...]

* Background.--While the resting left ventricular ejection fraction (LVEF) predicts prognosis in ischemic heart disease, clinical evaluation is also useful. Methods.--To compare the prognostic value of LVEF by resting radionuclide ventriculography with that of clinical signs and symptoms of congestive heart failure (CHF), 170 patients with suspected ischemic heart disease were followed up in this prospective study. Patients had a standardized history and physical examination performed by a study cardiologist immediately before the nuclear scan. Chest roentgenography and radionuclide ventriculography were performed in a standard manner. The diagnosis of CHF was made by validated clinicoradiographic criteria based on the Framingham study. Mortality was determined by means of the National Death Index; median follow-up time was 3 years. Results.--There was CHF at baseline in 70 patients, and baseline LVEF was low ([is less than or equal to] 0.4) in 63 patients. Low LVEF was significantly associated with CHF. During follow-up, 55 of the subjects died (overall mortality, 32%). Subjects with CHF had a significantly higher risk of death than those without CHF, and subjects with low LVEF had a higher mortality than those with preserved LVEF. Both CHF and LVEF were independent predictors of mortality. In a Cox model, each percentage increase in LVEF was associated with a 2% decreased mortality, while subjects with CHF had a mortality 2.5 times higher than that of those without CHF. Also, CHF with preserved LVEF had a better prognosis than CHF with depressed LVEF, but this prognosis was worse than that in subjects without CHF. Conclusions.--The clinical diagnosis of CHF, based on clinical evaluation and chest roentgenogram, is a valid predictor of mortality and provides information independent of the radionuclide LVEF in determining prognosis in patients with ischemic heart disease. (Arch Intern Med. 1992;152:2433-2437)

To evaluate the utility of nuclear morphometry as a prognostic indicator in lung cancer, 5-year follow-up information was obtained in 46 cases of surgically resected Stage I non-small cell lung cancer (NSCLC). Nuclear area, perimeter, major diameter, minor diameter, and nuclear shape factor were determined from representative histologic sections off the tumors with a computer-assisted digitizing system. The morphometric parameters were compared between patients with favorable outcome (Group I: alive with no evidence of disease, n = 17) and those with poor outcome (Group II: dead of disease or with recurrence of disease, n = 29). No significant differences in any of the morphometric parameters were found between tumors in Groups I and II for individual tumor cell types or the combined cases. Failure to demonstrate a correlation between morphometric parameters and prognosis in Stage I NSCLC indicates that future efforts to determine objective prognostic factors should concentrate on other variables, such as specific genetic abnormalities. Cancer 1992; 69:2454-2457.

Technetium-99m (TC-99m)-teboroxime is a new myocardial perfusion imaging agent. The purpose of this prospective study was to compare Tc-99m-teboroxime with thallium-201 imaging after the administration of dipyridamole. Thirty patients referred for the evaluation of chest pain were studied with both thallium-201 and Tc-99m-teboroxime dipyridamole scans (mean interval 2 days). Dipyridamole was administered at 0.142 mg/kg/min for 4 minutes. Planar imaging (3 standard views) was obtained at 5 and 240 minutes after the injection of 2.2 mCi of thallium-201. Tc-99m-teboroxime (18 to 25 mCi) was injected after dipyridamole infusion. A second injection, at rest, was repeated 4 hours later. Planar imaging (3 standard views of 1 minute/view for the first 2 views, and 90 seconds for the last view) was obtained 2 minutes after Tc-99m-teboroxime injection. Blinded reading was performed by 3 observers. Thallium-201 showed perfusion defects in 182 myocardial segments corresponding to 33 of 45 (73%) significantly stenosed coronary arteries ([is greater than or equal to]70% reduction in endoluminal diameter), and Tc-99m-teboroxime detected 160 abnormal segments corresponding to 29 of 45 (64%) stenosed arteries. Thallium-201 and Tc-99m-teboroxime studies were normal in 3 patients. In conclusion, this study shows that there is a good correlation in the imaging results found with thallium-201 and Tc-99m-teboroxime using dipyridamole infusion on both a segmental and a diagnostic comparison.

Acute or subacute ischemia (lack of blood flow due to an obstructed blood vessel) in the lower legs may be successfully treated using peripheral arterial thrombolysis (dissolution of clots blocking the vessel by injection of a thrombolytic solution into the artery). Thrombolysis used to treat patients with chronic arterial occlusion, on the other hand, has not been as successful. Thrombolysis is associated with a small but significant risk of death from stroke or other bleeding complications; therefore, it is important that patients be selected carefully. Unfortunately, arteriography (X-ray examination of an artery following injection of radio-opaque contrast dye) cannot distinguish between recent (acute) and chronic arterial obstruction. Imaging of platelets (cells involved in clotting) using radioisotope-labeled platelets can identify arterial thrombi (clots), but this is a complex and time-consuming procedure. A platelet-specific antibody (an immune protein produced in response to the presence of an antigen, in this case platelet-surface receptors) was assessed for its ability to identify arterial clots quickly and accurately. Seventeen patients with acute leg ischemia were studied using arteriography and platelet-specific antibody imaging. Arteriographic findings excluded four patients from clot-dissolving therapy; 13 patients underwent thrombolysis treatment. Of these 13 patients, six patients had positive antibody images; the identified arterial segment was reopened and at 30 days, four of these had remained open. Of the seven patients with negative scans, only four exhibited clot dissolution and two of these patients had reformation of clots. These findings suggest that platelet-specific antibody imaging can identify areas of acute arterial clot formation, and further studies may show this technique to be useful in selecting patients for thrombolytic therapy. (Consumer Summary produced by Reliance Medical Information, Inc.)

Lung cancer is the leading cause of cancer death in men aged 35 years or older, and the second leading cause of cancer death in women 35 to 74 years [...]

The value of the new radionuclide tracer, technetium-99m (Tc-99m) sestamibi, to demonstrate myocardial perfusion in areas supplied by specific coronary arteries was evaluated in patients injected with the agent during cardiac catheterization. Tc-99m sestamibi differs from thallium-201 in its physical characteristics (photon energy 140 keV) half-life (6 hours) and lack of significant redistribution allowing its administration during an episode of chest pain or ischemia occuring outside the nuclear medicine laboratory with later imaging to visualize the distribution. In 13 patients Tc-99m sestamibi was administered intravenously during balloon-occlusion angioplasty. In 11 to 13 patients, defects of the single photon emission computed tomography images corresponded to the area made ischemic during angioplasty. In the remaining 2 patients, abundant collateral flow was present and no defects were seen. In a second study, 15 patients had Tc-99 sestamibi selectively injected into a coronary artery during angiography. Later imaging identified the area supplied by the artery injected. Tc-99m sestamibi imaging can detect perfusion defects associated with short episodes of ischemia, and the area supplied by the different coronary arteries. (Am J Cardiol 1990;66:85E-90E)

One of the major dangers that cancer patients face is the spread (metastasis) of the cancer from its point of origin to other tissues and organs in the body. Bone scans are performed on cancer patients to detect changes that might be indicative of metastases. The scans can detect abnormalities, but cannot always determine if the abnormalities are due to cancer. Correlative radiographs (X-rays) are frequently taken of the bone abnormalities and are often used to make a final diagnosis. The reliability of using X-rays for final diagnosis in these cases has not been examined previously. Results of X-rays, taken after bone scans showing new abnormalities in cancer patients, were compared with the final diagnosis. A total of 306 scans indicating new abnormalities in patients without previously diagnosed metastases were performed. X-rays results initially appeared normal for 132 patients (43 percent); 22 (17 percent) of these abnormalities were later found to be cancerous. In 115 cases, X-rays results showed a benign condition such as a fracture; in only one case was cancer found at follow-up. X-rays results suggestive of cancer were seen in 17 cases, and 4 (24 percent) of these abnormalities were cancerous. X-ray results consistent with cancer were seen in 21 cases, of which 15 (71 percent) were cancerous. These results indicate that when correlative X-rays are taken in response to abnormal findings on bone scans in cancer patients, results showing a benign cause of the abnormality are reliable. However, if the findings are either normal or suggestive of cancer, further investigation is recommended. (Consumer Summary produced by Reliance Medical Information, Inc.)

Gastroesophageal reflux is a disorder often seen in children and infants in which food being digested is regurgitated and possibly aspirated. It is associated with a number of serious disorders that can be life-threatening. Diagnosis of this disorder often relies upon measuring gastric (stomach) emptying by scintigraphy (imaging of radioactively labeled materials given as food). Most of these tests are only performed for one hour. Research indicates that results vary widely for gastric emptying after one hour and that two or more hours is a realistic time between feedings. This study examined the usefulness of the emptying test in predicting emptying after two hours. The study involved examining the records of 181 patients given a gastric emptying test at one and two hours. The results found that the amount of gastric emptying measured after one hour could not be used to predict the amount of emptying after two hours. Gastric emptying is related to gastroesophageal reflux, in that low rates of emptying are indicative of the disorder. The problem in measuring emptying is that it can vary greatly in the initial stages. The results of this study indicate one hour is too short a time to get stable results and that for diagnostic use, gastric emptying should be measured for at least two hours. (Consumer Summary produced by Reliance Medical Information, Inc.)

Which Test(s) to Order--and Why A 14-year-old boy complains of diffuse abdominal pain, low-grade fever, and nausea of 24 hours' duration. He has no history of recent trauma. Temperature is [...]

INDIUM 111 ([sup.111] In) has been the primary radioisotope used to label leukocytes for detecting abscesses. Technetium 99m ([sup.99m] Tc), the most commonly used radioisotope in nuclear medicine, has a [...]

SUCCESSFUL TRANSPLANTATION OF cadaveric organs requires the removal of organs soon after the donor's death. A prompt determination of the donor's death is necessary to avoid deterioration of the organs [...]

Gastroesophageal reflux (GRE, regurgitation of stomach contents) is often seen in infants. It is implicated in a number of other diseases affecting infants, including asthma, failure to thrive, and sudden infant death syndrome (SIDS). Examination of gastric (stomach) emptying is used to detect GRE and its underlying causes. This often involves the use of radionuclides (radioactive material) to produce images of the upper gastrointestinal tract. The patient is fed a meal containing the radionuclide and then scanned for 90 minutes to measure gastric emptying rate. The lower limits for normal gastric emptying have been standardized as being 45 percent by 60 minutes and 60 percent by 90 minutes. Images are continually obtained during the 90 minutes. These images are enhanced by a computer and examined for any signs of reflux. The episodes of reflux are characterized and staged. This careful review of the images helps diagnose, characterize and find the underlying causes of delayed gastric emptying. Aspiration (taking into the lungs) of gastric contents is also studied after gastric emptying has been completed. The important question is whether delayed gastric emptying is an indicator of GRE. No definitive studies have been performed to show this, but it is likely that such a relationship exists. An article in the February 1991 issue of Radiology contends that gastric emptying test results may be highly variable, depending upon time examined, such that an abnormal result in a one-hour test might be normal in a two-hour test. The continuous and close evaluation of the emptying process yields important information beyond just the mere percentage of emptying at two time periods. Such data can be very useful in detecting GRE. (Consumer Summary produced by Reliance Medical Information, Inc.)

Scientists at Organon International in Netherlands have developed a novel approach for targeting radioisotopes to tumor cells as part of cancer radioimmunotherapy. The process involves the administration of an antibody-oligonucleotide conjugate and a radioisotope-carrying complementary oligonucleotide conjugate. The conjugate links to a tumor antigen while the complementary oligonucleotide attaches to the primary conjugate as the radioisope is directedto the tumor.

THALLOUS CHLORIDE Tl 201 is a safe, nontoxic radiopharmaceutical currently used to assess myocardial perfusion and viability. Its use has been increasing recently to detect tumors and to characterize tumor [...]