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PubMed2006

[Esophageal stricture following complete remission after chemotherapy for malignant lymphoma in an elderly patient].

A 75-year-old woman was given a diagnosis of malignant lymphoma (non-Hodgkin, diffuse large B cell type, stage IIA) at our hospital on August 2003. She received six courses of rituximab-based chemotherapy (R-CHOP regimen) and then she achieved complete remission. On August 16, 2004, she was readmitted in our hospital for difficulty in swallowing. Upper gastrointestinal endoscopy reveled esophageal stricture and an ulcerative lesion on the esophageal mucosa. The X-ray examination of the upper gastrointestinal tract reveled a severe esophageal stricture with niches and hiatus hernia. No malignancy was seen on CT scanning, gallium radioisotope scanning and histological examination of biopsy specimens with the upper gastrointestinal endoscopy. The physical examination showed gibbosity, and MR imaging showed multiple compression spined fractures. Finally, we diagnosed benign esophageal stricture with reflux esophagitis. She underwent laparoscopic partial esophagectomy in September 21, 2004, and the postoperative course was satisfactory. The pathological findings showed benign esophageal stricture caused by esophagitis. We report here a case of esophageal stricture following complete remission after chemotherapy for malignant lymphoma in an elderly patient.

Aged↗
PubMed1985

[Mechanism of 67Ga uptake by an experimental abscess--permeability of plasma from blood vessels in abscessed tissue].

In the previous paper, we reported that 67Ga was accumulated in abscess and uptake rate of 67Ga in abscess increased with time after the injection of 67Ga-citrate. The present study was undertaken to elucidate the influence of blood flow on the accumulation of 67Ga in abscess. Five days after subcutaneous injection of 0.2 ml of turpentine to the rats, 131I-human serum albumin (HSA) was injected intravenously to the rats. At an appropriate time after the injection (10 min to 6 days), uptake rates of 131I-HSA in abscess and normal tissues were measured. Similarly, 51Cr-red blood cells (RBC) were injected intravenously to the above rats and the uptake rates of 51Cr-RBC were also measured. One, three, and 24 hours after injection of 131I-HSA, the uptake rates of 131I-HSA in abscess were 1.32 %dose/g, 1.84 %dose/g, and 0.82 %dose/g, respectively. However, the uptake rates of 51Cr-RBC in abscess was very small, and the value was 0.14 %dose/g at 24 hours after the injection. In the case of abscess, blood in the tissue fluid was very little, but the permeability of 131I-HSA from the blood vessel in the tissue was much larger than that of normal tissues. From these facts, it was deduced that the accelerated permeability caused the abscess accumulation of 67Ga.

Abscess↗
PubMed2001

Advantages of short-lived positron-emitting radioisotopes for intracoronary radiation therapy with liquid-filled balloons to prevent restenosis.

UNLABELLED: Balloon catheters filled with liquid radioisotopes provide excellent dose homogeneity for intracoronary radiation therapy but are associated with risk for rupture or leakage. We hypothesized that the safety of liquid-filled balloons may be improved once positron emitters with half-lives below 2 h are used instead of the high-energy beta-emitters 166Ho, 186Re, or 188Re, all of which have a longer half-life of at least 17 h. METHODS: To support this concept, the suitability of 18F (half-life, 109.8 min), 68Ga (half-life, 67.6 min), 11C (half-life, 20.4 min), 13N (half-life, 9.97 min), and 15O (half-life, 2.04 min) for intracoronary radiation therapy was evaluated. Potential tissue penetration of positron radiation was assessed in a series of phantom experiments using Gafchromic film. Antiproliferative efficacy of positrons emitted by 68Ga was investigated in vitro using cultured bovine aortic smooth muscle cells (BASMCs), and was compared with gamma-radiation emitted by 137Cs. To characterize the remaining risk, we estimated radiotoxicity after accidental intravascular balloon rupture on the basis of tabulated isotope-specific doses (ICRP 53) and compared these values with 188Re. RESULTS: Half-dose depth of tissue penetration measured in phantom experiments was 0.29 mm for 18F, 0.42 mm for 11C, 0.54 mm for 13N, 0.79 mm for 15O, and 0.9 mm for 68Ga. Irradiation of cultured BASMCs with positron radiation (68Ga) induced dose-dependent inhibition of proliferation with complete proliferative arrest at doses exceeding 6 Gy. ED(50) and ED(80) were 2.5 +/- 0.4 Gy (mean +/- SD) and 4.4 +/- 0.8 Gy, respectively. Antiproliferative efficacy was equal to that of the 662-keV gamma-radiation emitted by 137Cs (ED(50), 3.8 +/- 0.2 Gy; ED(80), 8.0 +/- 0.3 Gy). Estimates made for patient whole-body and organ doses were generally below 50 mSv/1.85 GBq for all investigated positron emitters. The same dose estimates for 188Re were 6-20 fold higher. CONCLUSION: Among the studied radioisotopes, 68Ga is the most attractive source for liquid-filled balloons because of its convenient half-life, sufficient positron energy (2.92 MeV), documented antiproliferative efficacy, and uncomplicated availability from a radioisotope generator. The safety profile for 68Ga is significantly better than that of 188Re, which suggests this radioisotope should be evaluated further in preclinical studies.

Animals↗
PubMed1984

Evaluation of neutrophil labeling techniques using the chemotaxis radioassay.

Neutrophils isolated from human blood were labeled by various methods and exposed to a chemotactic gradient. The chemotactically functional cells that migrated into the gradient were isolated. The portion of radioactivity of the original cell suspension carried with the chemotactically responsive cells was related to the relative number of migrating cells as determined microscopically. Of the radionuclides used, P-32 diisopropylfluorophosphate (DFP), In-111 oxine, and Tc-99m sulfur colloid provided cell preparations with the highest relative portion of radioactivity confined to functionally intact (chemotactic) neutrophils. Results with Na2(51)CrO4 and with SnCl2-reduced 99mTcO4- were less than optimal. Neutrophils exposed to Ga-67 citrate apparently took up the label and retained chemotactic responsiveness. However, little or no radioactivity was detected in the neutrophils that migrated from the suspensions of Ga-67-labeled cells. The results indicate that the chemotaxis radioassay can yield unique information pertaining to the extent to which a radiotracer is specifically associated with viable neutrophils in a suspension of labeled cells.

Chemotaxis, Leukocyte↗
PubMed1981

[Nuclear medicine in pneumonology in the light of 9 year's experience at the S. Luigi Gonzaga Hospital].

An attempt is made to draw a picture of the results obtained with nuclear medicine in the pneumological field in the light of 9 years experience. An attempt is also made to identify from among recently introduced techniques (T.A.C., echotomography) which ones might be substituted for radioisotopes and when, and on what occasion they can be used as complementary treatment. It is concluded that nuclear medicine is of absolute value for functional examinations of the respiratory apparatus (perfusors and ventilators) and for lung onconscannning with Ga67 citrate and Bleomycin-Co57 under present circumstances and that in other fields certain morphological scans (bone scans) are still useful by virtue of their cost-benefit ratio.

Bleomycin↗
PubMed1981

Functional imaging of uptake of radiopharmaceuticals as a method for tumor visualisation in rats.

Dynamic studies of kinetics of 99mTcO4, 57Co-Bleomycin, 67Ga, A2 fraction of 57Co-Bleomycin in Yoshida sarcoma bearing rats were undertaken. Then the regional variations of rate of the initial uptake of a radiopharmaceutical were examined using functional representation of the rate constants as a function of position. It was concluded that--for radiopharmaceuticals with a high initial uptake rate--the method resulted in visualization of tumor and in suppression of the blood background, within five to eight minutes after administration. This approach based on an evaluation of the parameters of the radiopharmaceutical kinetics in organs and tumor makes possible the use of short-lived radionuclides for tumor visualization and could offer some possibilities of distinguishing the tumor from other accumulating organs.

Animals↗
PubMed1978

[Radiopaque hemithorax, with special reference to scintigraphic methods].

Radioopaque hemithorax is frequently observed. The various situations in which it may occur are examined aetiopathologically, along with the general and specifically radiological methods used for its investigation. Particular attention is given to the employment of radio-isotopes for this purpose and the methods involved. Results obtained with perfusion are noteworthy, and even more so those achieved with positive tracers such as 67Ga citrate and 57Co Blm, especially in the differential diagnosis of pleural effusion and mesothelioma through what is described as the "paradox effect".

Cobalt Radioisotopes↗
PubMedDate not supplied

Gene therapy using antisense oligodeoxynucleotides labeled with Auger-emitting radionuclides.

Antisense oligomers may be used as a vehicle for carrying a radiation source into a specific location inside a tumor cell. The effects of radioactive-labeled oligodeoxynucleotides (ODNs) may have both direct antisense inhibition and radiation. Thus far, the use of radioactive ODNs has been limited mostly to clinical biokinetic studies. Therapeutic possibilities remain unknown if the basic question of the optimal source of radiation is unanswered. We have shown previously that oligonucleotide therapy can be effective theoretically with the internally labeled ODN phosphorothioates 32P, 33P, and 35S. Here, we expand the selection of radionuclides; we calculated in vivo subcellular tissue distribution for ODN phosphorothioates using the decay characteristics of several beta- and Auger-emitting radionuclides: 32P, 35S, 51Cr, 67Ga, 111In, (1114m)In, 123I, 125I, 131I, and 201Tl. The absorbed nuclear doses of these radiolabeled oligonucleotides were estimated in different cellular dimensions using the subcellular biodistribution data for two oligonucleotides (ISIS 2105 and ISIS 2922). Our results indicate that Auger-emitter isotopes do not give higher absorbed cell nuclear doses than the isotopes suitable for internal labeling of ODN phosphorothioates. However, the biological difference is difficult to estimate. The best isotope for subcellular targeting was 35S, which gives the smallest variation of nuclear dose in the different cell dimensions we studied (nuclear diameter, 6-16 microm; cellular diameter, 12-20 microm). Therefore, we conclude that in oligonucleotide radiotherapy, nuclear targets should be treated with short-range beta-emitters (35S or 33P) that are suitable for the internal labeling of oligonucleotides unless the relative biological effectiveness of Auger-emitters could be remarkably improved. Dual labeling with 32P and 35S may provide therapeutic benefits when treating smaller and larger targets simultaneously. Further in vivo development, especially with 33P and 35S labels for ODNs, is strongly indicated.

Chromium Radioisotopes↗
PubMed1979

[Radioisotope topical diagnosis of malignant lymphomas using gallium-67 citrate].

The diagnostic value of Ga-67 citrate scintigraphy was estimated based on the comparison of clinical and roentgenological findings, including lymphography, in 46 patients with lymphogranulomatosis and other malignant lymphomas. The results obtained indicated that scintigraphy with Ga-67 citrate is a valuable adjunct for diagnosing malignant lymphomas and lymphogranulomatosis in previously untreated patients and in the recurrences.

Adult↗
PubMed1985

Diagnosis of intra-abdominal abscesses. A review.

Intra-abdominal abscess, resulting either from primary intraperitoneal disease or as a complication of surgery, remains a serious problem with high patient mortality if not treated early and adequately. The initial attempt at diagnosis rests on strong clinical evidence supported by nonspecific laboratory findings. The most helpful advance over conventional x-ray studies has been the advent of noninvasive imaging techniques such as ultrasonography or computed tomography. Radioisotopic scanning with gallium or indium makes possible a generalized survey of the peritoneal cavity, but only after a delay from the time of injection. Ultrasonography is somewhat limited in utility, particularly in the left subphrenic space, and CT scanning remains the technique with highest resolution. These noninvasive imaging techniques also have the potential for directed percutaneous catheter drainage.

Abdomen↗
PubMed1976

Radionuclide liver scans in tumor detection: current concepts.

Because of the frequency of spread of tumors arising elsewhere to the liver, hepatic evaluation plays a key role in planning therapy. Dynamic radionuclide transit studies depend upon the dual blood supply of the liver (hepatic artery and portal vein) and can be a useful prelude to static imaging, as most intrahepatic tumors have an hepatic arterial blood supply. Since most tumors do not have the ability to accumulate a radioactive colloid, static views are usually obtained after injection of particulates, which are accumulated by the reticuloendothelial system. A gross defect on the radiocolloid scan simply indicates the presence of an intrahepatic abnormality, but does not identify the nature of the lesion. The possible role to be played by use of additional radiopharmaceuticals, with different properties, in identifying the intrahepatic process is discussed. Other uses of liver scans, such as in evaluating the response of known intrahepatic lesions to therapy, are pointed out.

Chromium Radioisotopes↗
PubMed1987

Alterations in particle accumulation and clearance in lungs of rats chronically exposed to diesel exhaust.

F344 rats were chronically exposed to diesel exhaust at target soot concentrations of 0 (control, C), 0.35 (low, L), 3.5 (medium, M), and 7.0 (high, H) mg/m3. Accumulated lung burdens of diesel soot were measured after 6, 12, 18, and 24 months of exposure. Parallel measurements of particle deposition and clearance were made to provide insight into the mechanisms of particle accumulation in lungs. The fractional deposition of inhaled 67Ga2O3 particles after 6, 12, 18, and 24 months of exposure and of inhaled 134Cs-fused aluminosilicate particles after 24 months were similar for all groups. Progressive increases in lung burdens of soot particles were observed in M and H exposed rats, reaching levels of 11.5 +/- 0.5 and 20.5 +/- 0.8 mg/lung (mean +/- SE), respectively, after 24 months. Rats in the L group had smaller relative increases in lung burden, reaching levels of 0.60 +/- 0.02 mg/lung after 24 months. Tracheal mucociliary clearance measurements, using 99mTc-macroaggregated albumin deposited in the trachea, showed no changes at anytime. There were statistically significant increases in clearance half-times of inhaled radiolabeled particles of 67Ga2O3 as early as 6 months at the H level and 18 months at the M level; no significant changes were seen at the L level. Rats inhaled fused aluminosilicate particles labeled with 134Cs after 24 months of diesel exhaust exposure to measure long-term components of pulmonary clearance. The long-term clearance half-times were 79 +/- 5, 81 +/- 5, 264 +/- 50, and 240 +/- 50 days (mean +/- SE) for the C, L, M, and H groups, respectively. Differences were significant between the C and both the M and H exposure groups (p less than 0.01). Lung burdens of diesel soot were more than expected at the H and M levels and were also associated with impaired particle clearance while smaller responses were observed in both burdens and clearance at the L level.

Animals↗
PubMed1984

Radionuclide-labeled red blood cells: current status and future prospects.

Radiolabeling of red cells and their clinical and research application in nuclear medicine constitute an area of continued interest and steady growth during the past two decades. Significant advances have been made so that at the present time, radiolabels with sufficient in vitro and in vivo stability are available for diverse applications. Technetium-99m-labeled red cells in particular have revolutionized the field of cardiovascular nuclear medicine by making possible the external evaluation of various heart parameters with minimum radiation dose or trauma to the patient. Among other areas of study that use 99mTc -RBC are blood pool imaging, detection of vascular malformations, red cell mass determination, detection of gastrointestinal bleeding, and of hemangiomas. Heat-damaged 99mTc -RBC find application in spleen imaging, accessory spleen localization, detection of GI bleeding, and in other areas. A critical evaluation is presented of the various in vitro and in vivo labeling techniques that are currently available for red cell labeling. Even though the presently used procedures provide satisfactory labeled preparations, ideal radioisotopic RBC labels remain to be developed. Intermediate (2-3 days) as well as long-lived (approximately 30 days) radionuclidic labels are highly desirable for a number of clinical procedures where 99mTc is not useful due to its short half-life. A clearer understanding of the mechanistic aspects of various labeling reactions is expected to aid in the design of better and improved RBC labels that will help fulfill various areas of need in nuclear medicine applications. New approaches such as the use of radiolabeled antibodies to red cell antigens, or labeling specific receptor sites in the cell may lead to substantial improvements in the labeling methodology and could yield labeled cells with the least damage and maximum in vivo stability.

Chromium Radioisotopes↗
PubMed1984

Neutrophil labeling: problems and pitfalls.

The use of neutrophils labeled with gamma-emitting radionuclides has been shown to be acceptable for in vivo kinetic studies as well as for imaging inflammatory foci. Among the gamma-emitting radionuclides, indium-111 appears to be the agent of choice. Labeling neutrophils with 111In, however, is a relatively new technique. Although simple to perform, it involves several stages, none of which could be carried out without problems. These are discussed and the current research aimed at eliminating the problems is outlined. The knowledge of specific chemotactic receptors and surface antigens has stimulated investigations into selective neutrophil labeling that will continue to be challenging and exciting.

Animals↗
PubMed1999

Co, Fe and Ga chelates for cell labelling: a potential use in PET imaging?

The radiolabelling of blood cellular elements with PET radionuclides offers a higher sensitivity and resolution than conventional imaging, but short-lived PET radionuclides have limited clinical use in cell labelling. Medium half-life PET radionuclides, such as 55Co (t1/2 = 18.2 h), 52Fe (t1/2 = 8.3 h) and 66Ga (t1/2 = 9.4 h), enable quantitative uptake and cell kinetic studies with radiolabelled blood cellular elements. Co(II) oxine, Co(III) tropolonate, Fe(III) oxine, Ga(III) oxine and Ga(III) MPO were prepared using gamma-emitting radionuclides and a number of cell labelling parameters were investigated. The uptake of 57Co(II) oxine into erythrocytes was only 37%, and 65% of the activity eluted from the cells in cell-free plasma within 30 min. In contrast, high leukocyte and erythrocyte labelling efficiencies (> 90%) were obtained with 57Co(III) tropolonate containing cobalt carrier and the elution in cell-free plasma over 4 h was < 8%. High labelling efficiencies were also observed with 59Fe(III) oxine and 67Ga-MPO and the elution from leukocytes over 4 h was < 25%. We conclude that Co(III) tropolonate, Fe(III) oxine and Ga-MPO may be useful for radiolabelling leukocytes for PET investigations.

Cell Survival↗