Amplification of the antitumor activity of phleomycins and bleomycins in rats and mice by caffeine.

While having no antitumor effect per se, caffeine substantially enhanced the antitumor effects of the phleomycins PLM-CHP and PLM-PEP, and the bleomycins BLM-CHP and Blenoxane in rats carrying Walker 256 carcinosarcoma and/or mice carrying Ehrlich ascites tumor, even at doses of phleomycin and bleomycin below the minimum effective level. Positive but less conclusive results were also obtained with PLM-A4A4G and PLM-G.

Resolution of metastatic calcification revealed by bone scanning: case report.

We report here a case that shows the resolution of metastatic visceral calcification after correction of hypercalcemia. The resolution was visualized by serial whole body scans with the bone-scanning agent Tc-99m methylene diphosphonate.

Radionuclide demonstration of small-bowel anatomy in the afferent-loop syndrome: case report.

Radionuclide imaging with I-131 rose bengal and orally administered Tc-99m colloid was successfully used to show the presence of an afferent loop that was not visualized by radiographic, endoscopic, or ultrasonic procedures.

Production of cerebrospinal fluid leak artifact by residual 99mTc-pertechnetate.

Residual oropharyngeal 99mTc activity was detected on an 111In-DTPA cisternogram creating the appearance of a CSF leak. This can be prevented by employing a spectrometer setting that encompasses only the higher principal photopeak of 111In.

Gallium-67-citrate scanning of renal parenchymal malacoplakia.

UNLABELLED: The purpose of this article is to review the potential role of nuclear medicine scanning, especially with 67Ga, in the presumptive diagnosis and clinical management of patients with renal parenchymal malacoplakia (RPMP), a rare disease associated with coliform bacterial infection of the kidney and characterized by chronic unresolving inflammatory infiltrates containing von Hansemann macrophages in the renal parenchyma. METHODS: Published cases of RPMP were collected from the archival literature by searching the MEDLINE database and by reviewing bibliographic references contained in articles on malacoplakia. Data on the clinical features and radiographic evaluation of patients with RPMP were extracted from the clinical case reports. RESULTS: Forty-three cases of RPMP published over the past 20 yr were identified. Ten of the 43 patients (23%) had 67Ga scanning as a component of their diagnostic evaluation. In all 10 patients, renal uptake of 67Ga was classified as intense. Two of those 10 patients had serial 67Ga scanning performed to assess response to antibiotic treatment; both patients exhibited decreased uptake or complete resolution of abnormal renal uptake over time, a finding also exhibited by our patient. CONCLUSION: Intense renal uptake of 67Ga, typically in the clinical setting of fever, progressive renal failure and nephromegaly, strongly supports a diagnosis of RPMP. In those patients receiving prolonged antimicrobial therapy for RPMP, resolution of abnormal 67Ga uptake over time may provide an objective endpoint for treatment.

Technetium-99m-sestamibi SPECT localization of mediastinal parathyroid adenoma.

We report a case in which 99mTc-sestamibi SPECT was used to localize a middle mediastinum parathyroid adenoma that was not detected with planar sestamibi imaging on two previous occasions. Despite prior surgical exploration of the neck and mediastinum, the patient had a 20-yr history of hyperparathyroidism.

Localization of 99mTc-Sn-pyrophosphate in left ventricular aneurysms.

Concentration of 99mTc-pyrophosphate (99mTc-PPi) in the area of left ventricular aneurysms is discussed. In three cases clinical, laboratory, and electrocardiographic (ECG) evidence did not indicate that these patients currently had an acute myocardial infarction, but each patient had a clinical history and an ECG picture compatible with an old myocardial infarction. Cardiac catheterization revealed a large left ventricular aneurysm in all three cases. The reason for the preferential uptake of the radionuclide in the area of these aneurysms is not certain at this time.

Comparison of Tc-99m pyrosphosphate and Tc-99m hydroxymethylene diphosphonate in acute myocardial infarction: concise communication.

A clinical comparison between a new bone seeking radiopharmaceutical, Tc-99m hydroxymethylene diphosphonate (TcHMDP) and the standard agent, Tc-99m pyrophosphate (TcPPi), was performed in 18 patients with acute myocardial infarction. Each patient was imaged initially with either TcHMDP or TcPPi, and imaged 24 hr later with the other tracer. All 18 patients had images positive for acute myocardial infarction with TcPPi, whereas 16 of 18 patients (89%) had positive studies with TcHMDP. The TcPPi images were graded significantly superior to those obtained with TcHMDP in 61% of the patients, and they were equal in 33%. In only one patient (6%) was TcHMDP better. The results indicate that compared with TcHMDP, TcPPi not only has a superior sensitivity for acute myocardial infarction but also has a significantly increased intensity of uptake in positive areas. TcPPi remains the agent of choice for myocardial infarct imaging.

A comparison of brain imaging with gamma camera, single-photon emission computed tomography, and transmission computed tomography: concise communication.

We have evaluated the utility of a single-photon axial tomographic scanner (ECT) in brain imaging, using routine tracers in 238 patients. When compared with routine delayed gamma-camera images (DGCI), there was agreement in 191 negative studies and 39 positive studies. Four patients had positive DGCI and negative ECT studies, and four had positive ECT and negative DGCI. In the 102 patients in this series who also had transmission CT (TCT) studies, there were five who had positive emission studies and negative TCT, and 38 with an abnormal TCT and normal ECT. The ECT was occasionally helpful in distinguishing brain and skull metastases, in better portrayal of deep lesions, and in resolving equivocal DGCI findings. For the ECT to become clinically rewarding, however, we feel that it will need development of new tracers that will provide functional information in addition to that already attainable by routine gamma-camera images.

Relative lesion detection ability of Tc-99m HMDP and Tc-99m MDP: concise communication.

To compare the efficacy of Tc-99m HMDP and Tc-99m MDP to define skeletal lesions, 28 adult patients were examined in a double-blind, randomized, crossover study. Each patient was imaged with both agents over a period of 7-14 days. Both quantitative and qualitative evaluations were performed on the resulting images. Both agents detected the same number of skeletal lesions, and the number of lesions detected was the same whether the imaging was performed 2 or 4 hr after injection. Relative uptake of the tracer in the lesion relative to normal bone was also the same for both agents. Lesions were easier to see at 4 hr after injection than at 2 hr, presumably because soft-tissue levels were lower. Retention of tracer in bone compared with soft tissue was greater, and image quality was judged to be better, with Tc-99m HMDP than with Tc-99m MDP.

Conventional radionuclide brain imaging in the era of transmission and emission tomography.

The clinical applications for conventional radionuclide brain imaging have declined considerably since the introduction of newer imaging modalities (computerized cranial tomography [CCT], nuclear magnetic resonance [NMR]). Currently, conventional brain imaging primarily serves as a complementary test when CCT is negative or equivocal and strong clinical suspicion remains. Selected areas in which radionuclide imaging may be the preferred modality include evaluation of cerebral perfusion in assessment of brain death, detection of early viral encephalitis, evaluation of major venous sinus patency, external marking for localization of intracranial tumor, and in selected cases of suspected subdural hematoma, brain tumor, and cerebrovascular disease. The concept of conventional radionuclide brain imaging will likely undergo considerable change in the near future as newer radiopharmaceuticals are introduced and wider application is made of single photon emission computerized tomography (SPECT) and positron emission tomography (PET) imaging.

Special characteristics and potential of single photon emission computed tomography in the brain.

Single photon emission tomographic techniques for evaluation of the brain have as their major advantage the ability to employ readily available radionuclides, such as technetium-99m. With present radiopharmaceuticals, single photon emmision tomography of the brain primarily provides morphological information that may be complimentary to standard gamma camera images. Particular areas of assistance have included detection of basal lesions, delineation of multiplicity of lesions, definition of medial extent of abnormalities, clear separation of skull and intracranial abnormalities, and perhaps improved lesion characterization. Overall, however, the reported improvement in sensitivity has been relatively small. To optimally utilize the tomographic and quantiative capabilities of single emission tomography, new classes of radiopharmaceuticals must be developed that can penetrate the blood-brain barrier and provide information on CNS function and pathophysiology. If such radiopharmaceuticals can be labeled with single emission radionuclides, this technique has the potential to provide critically important information. The ultimate outcome of single emission tomographic techniques for the study of the brain may depend on radiopharmaceutical advances.

Conventional radionuclide cardiac imaging.

For more than two decades, conventional radionuclide techniques have been employed for the noninvasive evaluation of cardiac function. Standardized techniques have been developed and are widely available. Extensive clinical experience has confirmed the reliability of these techniques and has established important roles in providing diagnostic and prognostic information. Conventional radionuclide cardiac imaging currently emphasizes the demonstration of abnormalities in myocardial perfusion and ventricular function. Myocardial and radionuclide studies are infrequently employed but can offer helpful information in specific clinical situations.

Radionuclide techniques for brain imaging.

Over the past decade, many of the prime indications for radionuclide brain scanning have become instead indications for CCT, and nuclear medicine studies of the brain have assumed more of a complementary, supportive role. However, there is great promise for improvement in central nervous system radionuclide applications with advances anticipated in both radiopharmaceuticals and instrumentation. Nuclear medicine is continuing to function as a powerful research tool and, in the relatively near future, may regain its role as a major clinical test of the central nervous system.

Scintigraphic findings in renal malakoplakia.

The scintigraphic findings in a rare case of bilateral renal malakoplakia are presented. Markedly increased Ga-67 activity was present in both kidneys in sites corresponding to focal cortical defects on Tc-99m gluceptate (glucoheptonate) imaging. Interestingly, there was no abnormal renal activity with In-111 leukocyte scanning.

Plasmacytoma simulating meningioma on brain scan.

The flow study and static images of the brain scans of two patients with plasmacytoma of the skull were identical to the pattern most commonly seen with meningioma. There was a prominent blush on dynamic imaging which did not wash out combined with an intense uptake on static views adjacent to a meningeal surface. In patients with known multiple myeloma, the diagnosis of plasmacytoma of the skull or cranial cavity should be considered when this characteristic pattern is seen.

Tc-99m pertechnetate uptake in a thymoma: case report.

A case is reported to Tc-99m pertechnetate accumulation within an anterior mediastinal thymoma during a search for substernal goiter. This reemphasizes the non-specificity of Tc-99m pertechnetate uptake and the need for caution in using this agent to detect ectopic thyroid tissue.

Mediastinal uptake of I-131 in a hiatal hernia mimicking recurrence of papillary thyroid carcinoma.

I-131 is used to image patients diagnosed with papillary or follicular carcinoma of the thyroid after thyroidectomy to observe for metastatic disease or residual thyroid tissue. I-131 is excreted in gastric mucosa and is seen in the esophagus after the swallowing of saliva. The authors describe a patient in whom radiopharmaceutical activity in the mediastinum was subsequently shown to be due to a hiatal hernia.

Imaging of transplanted parathyroid tissue in a patient with recurrent hyperparathyroidism.

Parathyroid scintigraphy is useful in detecting residual hyperplastic parathyroid tissue in patients who continue to have hyperthyroidism after "total parathyroidectomy." Typically, only the neck and mediastinum are imaged. The authors report a case in which images of the forearm were helpful in detecting hyperplastic autologous transplanted parathyroid tissue.

The utility of adrenal scintigraphy in Cushing's syndrome and hyperaldosteronism.

Thirty-three adrenal scintigrams in 30 patients were reviewed to determine the utility of this noninvasive imaging technique. It was found to be very accurate in distinguishing bilateral from unilateral hyperfunction in patients who have clinical and biochemical evidence of adrenal cortical hyperfunction. The technique proved correct in 12 of 12 cases of Cushing's syndrome and 14 of 19 cases of hyperaldosteronism. Specific clinical questions were also answered in three miscellaneous cases.