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Biomedical subjects

O Israel

Publications and source records attributed to O Israel.

At least 73 records · Page 4Linked to original sources
PubMed1988

Gallium 67 imaging in monitoring lymphoma response to treatment.

The value of gallium 67 (Ga) imaging in monitoring lymphoma response to treatment was assessed in 25 patients with Ga-avid tumors and compared to body computed tomography (CT), chest radiographs, and palpation of tumor infiltrated peripheral lymph nodes. Ga imaging was negative in 95% (20/21) of the patients who were clinically considered to be in remission and in whom treatment was stopped. The disease did not recur during a follow-up of 12 to 26 months in 15 patients. Six patients developed recurrence of the disease 3 to 12 months after treatment was stopped. In all six patients Ga imaging became positive again at the time of the appearance of active disease. In the group of patients in remission, CT was negative in 57% (11/19), chest x-rays in 55% (6/11) and peripheral lymph nodes were palpated in none of the patients (13/13). In four patients that did not achieve remission after treatment, Ga scans were positive. Ga imaging appears useful in monitoring lymphoma response to treatment. This is probably because Ga imaging monitors tumor cell viability, whereas body CT and chest radiographs show the tumor mass, which may consist of fibrotic or necrotic tissue.

Adolescent↗
PubMed1988

Acute respiratory failure in hyperleukocytotic acute myeloid leukemia: the role of perfusion lung scintigraphy.

A patient with acute hyperleukocytotic myelogenous leukemia who presented with acute respiratory distress is reported. Clinical manifestations included dyspnea, tachypnea, hyperventilation, and cyanosis. Blood gas analysis revealed hypoxemia, hypocapnia, and metabolic acidosis. Chest X-ray and perfusion lung scanning were normal. Pulmonary leukostasis syndrome (PLS) was later confirmed at autopsy. In a patient with hyperleukocytosic from acute nonlymphocytic leukemia and respiratory distress, a normal perfusion lung scintigraph should make one consider the PLS.

Acute Disease↗
PubMed1988

SPECT quantitation of cobalt-57 bleomycin delivery to human brain tumors.

A newly developed and validated noninvasive quantitative SPECT method was used to measure the in vivo uptake of [57Co]bleomycin (Co-bleo) in 13 human brain tumors and the uptake of [99mTc]glucoheptonate (GH) in 23 brain tumors. Significant differences in tumor uptake were found. The tumor concentration over time, the tumor to blood radio at 30 min and the tumor cumulative concentration of radioactivity showed marked differences even between tumors with the same histology. Only a weak correlation was found between tumor concentration of Co-bleo and of GH. Therefore a simple imaging agent such as GH cannot, at the present time, serve as an indicator of individual tumor uptake and further experience with other agents is still necessary. Contrary to the generally held view, no correlation was found between the concentration of drug in the blood and its tumor concentration. It is suggested therefore that the level of a drug in the blood cannot be used as a criterion of the amount that will penetrate the tumor. Direct SPECT measurement of the concentration of the drug in the tumor itself should be performed. The bioavailability of a drug is critical in order for it to exert it tumoricidal effect. The results, showing marked differences in uptake between brain tumors, suggest that before chemotherapy is administered, uptake of the chemotherapeutic drug in the individual tumor to be treated should be assessed and comparisons should be made between the uptake of a series of drugs to determine which drug would be most efficacious on the basis of its uptake as well as its tumor cell killing potential.

Biological Availability↗
PubMed1988

Normal and abnormal single photon emission computed tomography of the skull: comparison with planar scintigraphy.

Using a rotating gamma camera the normal single photon emission computed tomography (SPECT) anatomy of the skull was defined in eight subjects. The value of SPECT as compared with planar scintigraphy was assessed in 34 patients with known or suspected disease of the skull. Seven patients had normal planar scintigraphy and SPECT. In 12 of 27 patients with bone involvement SPECT and planar scintigraphy showed essentially the same findings. In 15 patients SPECT was superior to planar scintigraphy. In three of these patients SPECT detected lesions while planar scan was normal. In the other 12 patients SPECT showed better anatomic localization and defined the full extent of the lesion. This was most obvious in patients with involvement of sphenoid, petrous, clivus, maxilla, and zygomatic bones. Our findings confirm the potential of SPECT to detect lesions in deep bones that are overlapped by superficial bony structures that cannot be visualized clearly with planar scintigraphy.

Bone Diseases↗
PubMed1987

Osteomyelitis and soft-tissue infection: differential diagnosis with 24 hour/4 hour ratio of Tc-99m MDP uptake.

The lesion-to-nonlesion 24 hour/4 hour ratio of technetium-99m methylene diphosphonate (MDP) uptake was used to distinguish osteomyelitis from increased bone uptake caused by adjacent soft-tissue infection. In a prospective study, this ratio was measured in 38 patients with 41 sites of increased uptake that were suspected to be osteomyelitis. The mean ratio was 1.18 +/- 0.18 in patients with proved osteomyelitis, which was significantly higher (P less than .001) than that in patients with increased uptake resulting from soft-tissue infection (0.98 +/- 0.05). On the basis of a receiver operating characteristic curve, a ratio of 1.06 was selected as the cutoff for differentiating osteomyelitis from soft-tissue infection. This method resulted in a sensitivity of 82%, a specificity of 92%, and an accuracy of 85%, and it appears to be more reliable than three- and four-phase scintigraphy, which are subjective and nonquantitative techniques.

Adolescent↗
PubMed1987

In vivo quantitation using SPECT of radiopharmaceutical uptake by human meningiomas.

A single photon emission computed tomographic method was designed for the measurement of radiopharmaceutical uptake in brain tumors. Results of phantom studies showed a correlation coefficient of .99 when measured volume was compared with actual volume. The correlation coefficient for measured radioactivity concentration compared with the actual concentration was .97. In 13 meningiomas the correlation between in vivo SPECT measurements of uptake and in vitro measurements in samples of the same tumors removed surgically was .84; when two tumors that contained regions of necrosis and fibrosis were excluded it was .93. This method can be used for in vivo quantitative assessment of pharmacokinetics of labeled drug uptake in human brain tumors.

Evaluation Studies as Topic↗
PubMed1987

Human lung tumors: SPECT quantitation of differences in Co-57 bleomycin uptake.

A newly developed single photon emission computed tomography (SPECT) method was used to measure noninvasively the concentration of labeled drugs in human lung tumors. The validity of the method was established by the high correlation (r = .92) between in vivo SPECT measurement of the concentration of glucoheptonate labeled with technetium-99m and in vitro measurement of the concentration of the drug in specimens of nine of the same tumors obtained at surgery. The in vivo concentration of intravenously injected bleomycin labeled with cobalt-57 was measured over time in 14 human lung tumors. Significant differences were found in the uptake of bleomycin by the tumors, even those with the same histologic characteristics, when the concentration over time, the tumor/blood ratio at 30 minutes, and the tumor cumulative concentration were measured in vivo. Since the drug concentration in the blood was not related to the concentration in the tumor (r = .54), uptake of chemotherapeutic drugs should be measured in each patient individually.

Adenocarcinoma↗
PubMed1987

Monitoring of 57Co-bleomycin delivery to brain metastases and their tumors of origin.

The concentration of cobalt-57 (57Co)-labeled bleomycin delivered to three brain metastases and to their tumors of origin in the lungs was measured using a single-photon emission computerized tomography technique. In two brain metastases the 57Co-bleomycin concentration measured at different times after the intravenous injection was significantly lower than that in the originating lung tumors (p less than 0.01 and p less than 0.001). In these two patients, the tumor cumulative concentration (TCC) of drug in the brain neoplasm compared to the lung carcinoma was 12.92 versus 15.12 and 10.30 versus 19.74 micrograms/cc/min. In the third patient there was no significant difference in drug concentration between the tumor in the brain and in the lung (TCC 16.02 vs. 15.09 micrograms/cc/min). There was a significant difference in the drug TCC between the three brain metastases: the difference between the lowest and highest concentrations was more than 50% (10.3 vs. 16.02 micrograms/cc/min). When the concentration in the tumor over time (CT(t)) of the 57Co-bleomycin was compared in the brain and lung tumors, a good correlation was found in each of the three cases (r = 0.93, 0.99, and 0.97). This suggests that the difference in drug uptake between brain metastases and their originating lung tumor is a quantitative rather than a qualitative phenomenon. The results show that the amount of drug to which brain metastases are exposed varies and may be very low in some tumors; therefore, effectiveness of drug delivery may play a role in the nonresponsiveness of brain metastases to treatment.

Bleomycin↗
PubMed1986

Superior sagittal sinus thrombosis: assessment with Tc-99m labeled red blood cells.

The diagnostic value of scintigraphy with technetium-99m labeled red blood cells (Tc-RBC) was assessed in 19 patients with clinical suggestion of superior sagittal sinus thrombosis (SSST). Comparison of Tc-RBC static images with dynamic flow studies in the brain showed a sensitivity of 100%, specificity of 86%, and accuracy of 94% for static studies and values of 87%, 20%, and 61%, respectively, for the flow studies. Tc-RBC scintigraphy enables direct visualization of the integrity of the superior sagittal sinus, whereas CT scanning shows various but nonspecific changes in the brain associated with SSST. Single-photon emission CT study using Tc-RBC, performed in six patients, appears to have potential in the diagnosis of SSST, allowing separation of vascular structures that are superimposed on the superior sagittal sinus in planar scintigraphy study.

Adolescent↗
PubMed1986

Quantitative analysis of tight junctions and the uptake of 99mTc in human gliomas.

The structural dimensions of capillary tight junctions and the uptake of 99mTc pertechnetate in human gliomas were studied. Quantitative analysis revealed a correlation between the uptake of radionuclides and the length of endothelial tight junctions. It is suggested that brain scintigraphy might be used for the selection of malignant brain tumors with altered tight junctions which might be accessible to chemotherapy with water-soluble agents.

Blood-Brain Barrier↗
PubMed1986

Scintigraphic findings in Gaucher's disease.

Gaucher's disease involves the liver, the spleen, and the bone. Liver-spleen and bone scintigraphy were used during an 8-yr period to evaluate changes caused by this disease. Patients were investigated with a liver-spleen scan for abdominal pain, mechanical discomfort, enlarged liver or spleen on physical examination, abdominal mass, abnormal liver function tests, and symptoms of hypersplenism. Fourteen liver-spleen scans were performed in nine patients. Liver scintigraphy showed various degrees of enlargement and inhomogeneous uptake. In two patients focal defects were detected. In one, focal defects were due to liver involvement with Gaucher's disease, but in the other they were caused by metastatic pancreatic carcinoma. The study was also useful in detecting splenic infarction and in following enlargement of the spleen after partial splenectomy. The main indication for bone scintigraphy in six patients was bone pain. This was found to be caused by either aseptic necrosis of the head of the femur, bone infarction, pathological fractures, or osteomyelitis. Loosening after total hip replacement was ruled out in three patients and missed in one patient. Scintigraphy appears to be a simple, sensitive test for evaluation of the liver, spleen, and bony skeleton in patients with symptomatic Gaucher's disease.

Bone Diseases↗
PubMed1985

Stress fractures and bone pain: are they closely associated?

The relationship between bone pain and stress fractures diagnosed by bone scintigraphy was investigated in military recruits during active training. In three patients pain appeared in the site of abnormal uptake 7-14 days after the bone scan in a previously asymptomatic site. One hundred and twenty-four sites of stress fractures were found in 64 patients; 32 (26 per cent) were asymptomatic. In 38 patients (59 per cent) there were multiple stress fractures; 32 (33 per cent) had asymptomatic stress fractures. Fifty-three per cent of the regions with abnormal uptake in the femur were painless, compared with 17 per cent in the tibia. The necessity for imaging all bones susceptible to stress fractures, even when asymptomatic, is stressed. It is suggested that diagnosis of stress fracture should be made when typical abnormal uptake appears on scintigraphy. Bone pain in such cases may be delayed.

Adolescent↗