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PubMedDate not supplied

Left ventricular ejection fraction calculated from gated technetium-99-sestamibi SPECT.

BACKGROUND: The accuracy of the left ventricular ejection fraction (LVEF) calculated from gated single photon emission computed tomography (GSPECT) studies is dependent on the accuracy of the determination of the end-diastolic volume (EDV) and end-systolic volume (ESV) of the left ventricle (LV). In this study we evaluated the feasibility of calculating the EDV, ESV and LVEF from the area under the polar graph (APC) of the edges of the LV image determined by a first derivative edge-detection method. METHODS AND RESULTS: Technetium-99m ((99m)Tc) sestamibi GSPECT studies and planar equilibrium radionuclide ventriculography (ERNV) were performed on 15 male subjects in whom the LVEF ranged from 19% to 75%. Images were reconstructed to obtain short axis slices of the LV spanning the cardiac cycle. On each slice the LV edge points were determined at 10 degrees intervals using the APC method. The area of each short axis slice was determined by conversion to polar co-ordinates, interpolation and numerical integration of the graphs and multiplication by a pre-determined conversion factor. RESULTS: Edges were successfully determined in all 15 patients using the APC method. The LVEF results correlate well with conventional planar ERNV studies (r = 0.96, LVEF(GSPECT) = 8.80 + 0.66 LVEF( ERNV)). The absolute difference between the LVEF for ERNV and for the APC method was 6.1% with a standard deviation of 7.6%. The reproducibility of SPECT LVEF using the APC method was good (intra-observer r = 0.99, inter-observer r = 0.99). CONCLUSIONS: The APC method provides for easy and accurate ejection fraction determination with limited underlying mathematical assumptions. The ability to interpolate the edge points provides for stable edge detection even in hypoperfused myocardium.

Adult↗
PubMed2001

Effective renal plasma flow calculated from a single blood sample following Technetium-99m mercaptoacetyltriglycine renal scan can predict delayed graft function in renal transplantation.

PURPOSE: Effective renal plasma flow (ERPF) can be calculated by obtaining a single blood sample at a fixed time after injection in a patient undergoing a technetium-99m mercaptoacetyltriglycine (99mTc MAG3) renal scan. The purpose of this study was to determine whether the calculated ERPF following cadaveric renal transplantation could accurately predict the need fordialysis within the first 10 postoperative days or the serum creatinine at postoperative day 10. MATERIALS AND METHODS: Between February 1994 and September 1998, 41 patients underwent 45 99mTc MAG3 renal scans within the first 10 days following a cadaveric renal transplantation at Harbor-UCLA Medical Center. A blood sample was drawn 44 minutes after injection of 99mTc and was used to calculate ERPF. This calculated ERPF was compared to measures of early function, such as the need for dialysis and serum creatinine. RESULTS: Decreased ERPF strongly correlated with the need for dialysis within the first 10 postoperative days (p < .0001). No patient with ERPF >210 mL/min/1.7 M2 required dialysis, whereas 35% (6/17) of patients with ERPF < or =210 mL/min/1.7 M2 required dialysis within the first 10 postoperative days. For those patients who did not undergo dialysis, the calculated ERPF was significantly related to the serum creatinine on postoperative day 10 (p<.0001 ). CONCLUSIONS: ERPF can be calculated from a single blood sample when performing a 99mTc MAG3 renal scan following cadaveric renal transplantation. This calculated ERPF provides a useful clinical tool to identify patients at high risk for development of delayed graft function.

Cadaver↗
PubMed1975

Technetium-99m-pyridoxylideneglutamate: a new hepatobiliary radiopharmaceutical. II. Clinical aspects.

Technetium-99m-pyridoxylideneglutamate (99mTc-PG) is a nontoxic radiopharmaceutical that was found to undergo rapid biliary excretion in normal humans. The biliary tree and gallbladder were seen within 10-15 min of injection and by 20 min marked accumulation of radioactivity was noted in the gallbladder and gastrointestinal tract. Of ten "control" volunteers, seven had normal 99mTc-PG-cholescintigrams. In the remaining three, the gallbladder was not visualized. Gallbladder disease was not excluded in these three subjects. Of 24 patients referred for investigation of right upper quadrant abdominal pain, 13 proved to have gallbladder disease. All seven patients with acute cholecystitis and one of four patients with chronic cholecystitis had nonvisualization of the gallbladder on the cholescintigram whereas five patients with chronic cholecystitis or cholesterolosis had normal cholescintigrams. Six of the eight patients with nonvisualization of the gallbladder on cholescintigram had contrast radiologic studies (oral cholecystogram or intravenous cholangiogram or both), and in all six, nonvisualization of the gallbladder was also reported on the contrast study. cholescintigraphy was found to be greatly inferior to contrast radiologic studies in the detection of gallbladder stones. Eleven patients had complete extrahepatic biliary obstruction and this diagnosis was correctly made in all 11 by the cholescintigram. Fourteen patients had incomplete extrahepatic biliary obstruction. The correct diagnosis was made on the cholescintigram in seven but in the remaining seven it was not possible to distinguish between incomplete extrahepatic biliary obstruction and hepatocellular disease. Malignant lesions (carcinomas of head of pancreas, gallbladder, common bile duct or ampulla of Vater) were the cause of obstruction in 10 of the 25 patients with complete or incomplete obstruction and the diagnosis of obstruction due to malignancy was correctly made in 8 of these 10 by means of a scintigraphic equivalent to Courvoisier's sing. Finally, 11 patients had hepatocellular disease and a nonspecific pattern consistent with either imcomplete biliary obstruction or hepatocellular disease was observed on the cholescintigram in all 11. The 99mTc-PG cholescintigram is suggested for a role complementary to that of contrast radiologic studies in the preoperative investigation of patients with possible surgical disease of the biliary tract. Contrast radiologic techniques are advocated as being more appropriate in the nonjaundiced patient with suspected gallbladder disease whereas the 99mTc-PG cholescintigram is advocated as being more appropriate in the patient with jaundice. The value of the 99mTc-PG cholescintigram lies in the confidence with which complete extrahepatic biliary obstruction can be diagnosed. The "scintigraphic Courvoisier's sign" seems a useful indicator of malignant obstruction.

Ampulla of Vater↗
PubMed2000

Detecting residual ischemia and identifying coronary artery disease after myocardial infarction using dobutamine technetium-99m-MIBI SPECT.

OBJECTIVE: To evaluate dobutamine technetium-99m methoxy isobutyl nitrile (sestamibi) single-photon emission computed tomography (Dobu-ECT) in detecting residual ischemia and identifying coronary vessel disease after myocardial infarction. METHODS: Sixty-two patients with confirmed myocardial infarction were studied with Dobu-ECT at the time of coronary artery angiography. Dobutamine was administered intravenously in incremental rates from 5 to 40 micrograms.kg-1.min-1 at 3-minute intervals. At the highest infusion rate, 7.4 x 10(8) Bq 99mTc-MIBI was injected intravenously, and tomographic imaging was performed after one hour. Resting images were taken after 24 hours, with a second dose of 99mTc-MIBI. RESULTS: The sensitivity of Dobu-ECT in detecting residual ischemia of myocardial infarction was 76%, which was higher than dobutamine electrocardiography (Dobu-ECG). Regardless of the single-, double- or triple-vessel diseases, Dobu-ECT was superior to Dobu-ECG in identifying residual ischemia (56% vs 4%, 86% vs 27%, 100% vs 47%, P < 0.01, respectively). The incidence of residual ischemia in patients receiving thrombolytic therapy was 67%, lower than patients without thrombolysis (72%) or those with an old myocardial infarction (94%). But the differences were not statistically significant. Dobu-ECT detected only 56% of ischemias in non-infarct related myocardium. Eighty-two percent of all significantly stenosed vessels were detected with Dobu-ECT, and 84% of patients with multivessel disease could be accurately identified. The sensitivity of Dobu-ECT was significantly greater for detecting severe stenosis over moderate stenosis. The sensitivity for detecting stenosis in the right coronary artery was greater than left anterior descending or left circumflex, but its specificity was lower. CONCLUSION: Dobu-ECT can identify residual ischemia, as well as its location and extent after myocardial infarction. Dobu-ECT can also accurately detect significantly stenosed vessels.

Adult↗
PubMed1999

[Evaluation of clinical value of technetium-99m(V) dimercaptosuccinic acid SPECT in diagnosis of parotid lump].

OBJECTIVE: To evaluate the clinical value of single photon emission computed tomography (SPECT) on classifying parotid lump as benign or malignant before treatment. METHODS: SPECT images of the parotid region were obtained in forty-five patients with parotid lump before surgery. We used technetium-99m(V) dimercaptosuccinic acid as imaging agent. The results were compared with their pathological diagnoses, clinical examination, and ultrasonography. RESULTS: The sensitivity, specificity and accuracy of Tc-99m(V)-DMSA SPECT imaging in determining malignancy of parotid lump were 93.7%, 72.4%, 80.0%, respectively. The uptake ratios of parotid lesions were higher in malignant tumors than benign tumors, cysts, and inflammatory lumps (P < 0.05). CONCLUSION: It is suggested that Tc-99m (V)-DMSA SPECT can be a useful aided method of preoperative diagnosis of parotid lumps. The uptake ratios can help increase the accuracy of diagnoses. For the benign tumors and inflammatory masses of parotid gland, the diagnoses had some false positives which may be reduced by combined clinical examination and ultrasonography.

Adolescent↗
PubMed2001

[Significance of lung perfusion scanning with technetium labeled macroaggregated albumin and pulmonary function assay for diagnosis of early hepatopulmonary syndrome].

OBJECTIVE: To evaluate the values of pulmonary function assay and dynamic pulmonary perfusion imaging with technetium labeled macroaggregated albumin ((99m)TcMAA) in the early diagnosis of hepatopulmonary syndrome (HPS). METHODS: The pulmonary function assay and (99m)TcMAA scans were performed in 28 patients with HPS, 30 cirrhotic patients (CP) without HPS, and 21 healthy controls (HC). RESULTS: In the patients with HPS, PaO(2), SaO(2) and diffusion capacity for carbon monoxide of lungs (DLco) was significantly lower than that in CP (P<0.01) and HC (P<0.01), and alveolar-arterial gradient [P((A-a))O(2)] was significantly increased (P<0.001). Results from (99m)TcMAA scans showed that the radionuclides were distributed over the spleen, kidney, liver and brain, and the ratios of arterivenous shunt were significantly higher than that in CP (P<0.001) and NC (P<0.001). In cirrhotic patients, DLco significantly decreased (P<0.05), P((A-a))O(2) and shunt ratios increased (P<0.01 and 0.001). CONCLUSIONS: Pulmonary function assay and dynamic pulmonary perfusion imaging with (99m)TcMAA are sensitive methods for diagnosis of the early HPS.

Hepatopulmonary Syndrome↗
PubMedDate not supplied

Comparison of technetium-99m tetrofosmin and gallium-67 citrate scintigraphy for detecting malignant lymphoma.

The aim of this study was to compare the value of technetium-99m tetrofosmin (Tc-TF) scintigraphy with that of gallium-67 citrate (Ga-67) scintigraphy for detecting malignant lymphoma. In this study, 50 patients with malignant lymphoma underwent Tc-TF and Ga-67 scintigraphy before receiving any therapy. Tc-TF scintigraphy detected malignant lymphoma in 44 (88%) patients, but was false-negative in 4 cases of infradiaphragmatic malignant lymphoma and in 2 cases of malignant lymphoma with chemotherapy resistance. Ga-67 scintigraphy detected malignant lymphoma in 45 (90%) patients, but was false-negative in 3 cases of low-grade non-Hodgkin's lymphoma and in 2 cases of malignant lymphoma with bone marrow involvement. There was no significant difference in sensitivity between Tc-TF and Ga scintigraphy. However, a combination of Tc-TF and Ga-67 scintigraphy detected malignant lymphoma in all 50 patients (100%). We conclude that it is necessary to combine Tc-TF and Ga-67 scintigraphy to accurately detect malignant lymphoma.

Adult↗
PubMed1975

Vial retention of technetium-99m sulfur colloid in commercial kits.

Vial retention of technetium-99m sulfur colloid in five commercial kits used for the preparation of this radiopharmaceutical was studied. Radiochromatography and microscopic particle sizing were performed on all products; the biologic distribution in rats of two products was tested. Loss of activity attributable to vial retention was evident with only two products. The resulting loss of specific concentration did not affect biologic distribution. The cause of the "plating-out" of the radiopharmaceutical on the interior reaction vial surface was not determined, although the gelatin component of the product was suspected to be a factor.

Colloids↗
PubMed1975

Technetium-99m-labeled stannous imidodiphosphate, a new radiodiagnostic agent for bone scanning: comparison with other 99mTc complexes.

Imidodiphosphate (IDP) is an analog of pyrophosphate and diphosphonate, with a P-N-P bond instead of P-O-P or P-C-P. We have labeled IDP with 99mTc quantitatively (98%) using stannous ions as the reducing/complexing agent in a freeze-dried kit form. Radiobioassay of this compound was carried out in rabbits and the results were compared with those of eight other Tc-labeled bone-imaging agents, using the performance of simultaneously administered 85Sr as a reference standard. The 99mTc-IDP concentrated 20% higher in the bone, and its soft-tissue and blood levels were lower than with 85Sr. By comparison, the concentrations in the bone of the other 99mTc agents were 20% less than that of 85Sr. Regarding blood levels, Tc-IDP performed worse than the Tc-diphosphonate but better than the pyrophosphate and the other technetium complexes. Scintillation camera images of 99mTc-IDP in both rabbits and dogs showed excellent details of the skeleton. In a preliminary human study, images with 99mTc-IDP were somewhat inferior to those comparably procured with 99Tc-methylene diphosphonate, but count rates with the IDP complex were about twice those with the MDP compound. Because of its better bone uptake, however, it is suggested that 99mTc-IDP may be clinically useful in spite of its relatively slow blood clearance.

Adult↗
PubMed1975

Technetium-99m-human fibrinogen.

Exogenous fibrinogen has been successfully labeled with 99mTc using a modified electrolytic method. The exact labeling mechanism has not been determined. Experimental data suggest that the labeling process of 99mTc-fibrinogen is quite similar to that of 99mTc-human serum albumin as reported earlier by Benjamin. Technetium-99m-fibrinogen is stable in human plasma or in 1% buffered human serum albumin. A binding efficiency of 76% has been achieved with approximately 25% clottable protein. The entire labeling procedure requires less than 1 hr of preparation time. This short labeling time in a closed system may allow development of a practical method for labeling autologous fibrinogen, thus eliminating the risk of hepatitis transmission.

Fibrinogen↗
PubMed2002

Ultrasound grade of hydronephrosis and severity of renal cortical damage on 99m technetium dimercaptosuccinic acid renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty.

PURPOSE: We performed ultrasonography and (99m)technetium dimercaptosuccinic acid (DMSA) renal scan in infants with unilateral hydronephrosis during followup and after pyeloplasty to examine the correlation of ultrasound hydronephrosis grade with the severity of renal cortical damage and assess the recovery of renal function in the obstructed kidneys after surgery. MATERIALS AND METHODS: We studied 80 boys and 19 girls with unilateral hydronephrosis detected in the first year of life, including 75 (76%) in whom it was detected prenatally. Ultrasound images were graded according to the Society for Fetal Urology grading system. The severity of renal cortical damage was assessed by DMSA renal scan. Absolute function of the right and left kidneys was estimated by DMSA uptake and relative DMSA uptake was calculated by the formula, relative uptake = uptake in obstructed kidney/total uptake in right and left kidneys x 100%. RESULTS: On ultrasonography grades 1 to 4 hydronephrosis were diagnosed in 9, 21, 19 and 50 kidneys, respectively. On DMSA renal scan cortical damage was detected in 10 kidneys (53%) with grade 3 and 49 (98%) with grade 4 hydronephrosis but not in kidneys with grade 1 or 2 disease. Dysfunction in the obstructed kidney, defined as relative DMSA uptake less than 40%, was noted in 13 patients with grade 4 hydronephrosis. Relative DMSA uptake significantly increased after successful pyeloplasty compared with preoperative uptake (44% +/- 2% versus 40.1% +/- 2%, p <0.01). CONCLUSIONS: Ultrasound grading of hydronephrosis correlates with the severity of cortical damage or the decrease in renal function on DMSA renal scan. Differential renal function on DMSA renal scan may be a useful and less invasive tool for determining surgical indications and examining changes in renal function after surgery.

Female↗
PubMed2002

Technetium-99m methoxyisobutylisonitrile imaging in the follow-up of differentiated thyroid carcinoma.

OBJECTIVE: To evaluate the potential of technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) imaging as an alternative to I-131 total-body scan (I-131 TBS) for the follow-up of patients with differentiated thyroid carcinoma (DTC). PATIENTS AND METHODS: We performed 87 Tc-99m MIBI imaging studies in 76 DTC patients who had total or near-total thyroidectomy followed by a radioactive iodine ablation while receiving thyroxine therapy. The final diagnosis was correlated with I-131 TBS, serum thyroglobulin (Tg), other conventional imaging modalities, clinical outcome, and/or pathological report. RESULTS: Seventy-six recurrent tumours or metastatic conditions in 58 DTC patients were detected. The overall findings of Tc-99m MIBI showed 72% sensitivity, 100% specificity and 77% accuracy. The figures for I-131 scan were 57%, 100% and 66%, respectively. When classifying upon tumour locations, Tc-99m MIBI imaging had sensitivity of 79% for cervical, 50% for mediastinal, 65% for skeletal and 69% for pulmonary metastases and the corresponding values for I-131 TBS were 33%, 67%, 94% and 75%, respectively. Furthermore, Tc-99m MIBI could detect only 44% of thyroid remnants demonstrated by radioiodine scan. CONCLUSIONS: Tc-99m MIBI imaging is more sensitive than I-131 TBS in detecting tumours in the neck but less sensitive for metastasis elsewhere, as well as thyroid remnants. Therefore, Tc-99m MIBI imaging should not substitute but rather complement I-131 TBS for evaluation of DTC patients post-radioiodine ablation.

Adenocarcinoma, Follicular↗
PubMed2002

Anti-CEA monoclonal antibody: technetium-99m labeling and the validation process of a scintigraphic animal model with a non-cellular antigenic implant.

Animal models are currently used to verify the biodistribution of different radiopharmaceuticals before its clinical application in Nuclear Medicine; however, there may be some limitations. The utilization of labelled anti-tumor monoclonal antibodies (MoAb) in experimental models often requires implant of human antigens (usually a cellular implant), which cannot be achieved in immunocompetent animals. Our purpose was to label an anti-CEA MoAb with technetium-99m (99Tc) and to validate a simplified animal model using a noncellular antigenic implant. MoAb was directly labelled with 99mTc, after reduction with 2-mercaptoethanol. Labeling efficiency was checked by ascending chromatography and immunoreactive fraction was measured in plastic wells sensitized with the antigen. Radiopharmaceutical biodistribution was evaluated by dissection and scintigraphy in 5 mice groups; following the subcutaneous administration of Al(OH)3, CEA adsorbed Al(OH)2 and a control group evaluation. Labeling efficiency was 94+/-3%, which showed to be stable for 24 hr, with immunoreactive fraction above 50%. Invasive biodistribution evaluation showed prolonged blood retention, hepatic and renal uptake. A significant increase in uptake was observed in scintigraphic studies of animals with CEA-adsorbed Al(OH)3 implants compared with the other groups (p<0.05). The non-cellular antigenic implant model simplifies the pre-clinical evaluation of labelled MoAb.

Animals↗
PubMed2002

Increased uptake of technetium-99m-hexamethylpropyleneamine oxime related to primary leptomeningeal melanoma.

We present an autopsy case of primary leptomeningeal melanoma visualized with technetium-99m-hexamethylpropyleneamine oxime (Tc-99m-HMPAO) single photon emission CT (SPECT) of the brain. Increased uptake of Tc-99m-HMPAO coincided with leptomeningeal enhancement on MR images and with the tumor location of the autopsy findings. It was thought that Tc-99m-HMPAO could correlate closely with melanoma. Tc-99m-HMPAO SPECT clearly showed primary leptomeningeal melanoma and severe hypoperfusion induced by intracranial hypertension and tumor proliferation.

Adult↗
PubMed2002

Detection of cervical lymph node metastases in nasopharyngeal carcinomas: comparison between technetium-99m methoxyisobutylisonitrile single photon emission computed tomography and magnetic resonance imaging.

We compared the effectiveness technetium-99m methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) and magnetic resonance imaging (MRI) of head and neck in evaluating cervical lymph node (LN) metastasis in nasopharyngeal carcinomas (NPC). Forty NPC patients with cervical LN metastases confirmed histopathologically underwent Te-99m MIBI SPECT and MRI of the head and neck to evaluate cervical LN metastases. For 16 LN lesions with discordant results between Tc-99m MIBI SPECT and MRI, Tc-99m MIBI SPECT could correctly detect 1 metastatic and 10 benign LN lesions as well as MRI could correctly detect 3 metastatic and 2 benign LN lesions. Agreement positive results of Tc-99m MIBI SPECT and MRI could correctly detect all of the remaining 24 metastatic LN lesions. Tc-99m MIBI SPECT has a better specificity but a lower sensitivity for detecting cervical LN metastases in NPC when compared with MRI. The combined use of Tc-99m MIBI SPECT and MRI could increase the accuracy compared with the single use of either Te-99m MIBI SPECT or MRI to detect cervical LN metastases in NPC.

Adult↗
PubMed2002

Comparing whole body 18F-2-deoxyglucose positron emission tomography and technetium-99m methylene diophosphate bone scan to detect bone metastases in patients with non-small cell lung cancer.

Despite advances in morphological imaging, some patients with non-small cell lung cancer (NSCLC) are found to have non-resectable disease at surgery or die of recurrence within a year of surgery. At present, metastatic bone involvement is usually assessed using conventional technetium-99m methylene diophosphate (Tc-99m MDP) whole body bone scan (bone scan), which has a high sensitivity but a poor specificity. We have attempted to evaluate the usefulness of whole body positron emission tomography with 18F-2-deoxyglucose (FDG-PET) for the detection of malignant bone metastases of NSCLC, and to compare FDG-PET results with Bone Scan findings. Forty-eight patients with biopsy-proven NSCLC and suspected to have stage IV disease underwent whole body bone scan and FDG-PET to detect bone metastases. The final diagnoses of bone metastases were established by operative, histopathological findings or clinical follow-up longer than 1 year by additional radiographs or following FDG-PET/Tc-99m MDP bone scan findings showing progressively and extensively widespread bone lesions. A total of 138 bone lesions found on either FDG-PET or Tc-99m MDP bone scan were evaluated. Among the 106 metastatic and 32 benign bone lesions, FDG-PET and Tc-99m MDP bone scan could accurately diagnose 99 and 98, as well as 30 and 2 metastatic and benign bone lesions, respectively. Diagnostic sensitivity and accuracy of FDG-PET and Tc-99m MDP bone scan were 93.4% and 92.5%, as well as 93.5% and 72.5%, respectively. In conclusion, our data suggest that FDG-PET with the same sensitivity and a better accuracy than those of Tc-99m MDP bone scan to detect metastatic bone lesions in patients with biopsy-proven NSCLC and suspected to have stage IV disease.

Adult↗
PubMed2000

[The measurement of tracheo-bronchial mucociliary clearance by technetium-99m DTPA aerosol scintigraphy].

Mucociliary clearance of respiratory channels is one of the important mechanisms guarding against retention of foreign particles within the lungs. Thus objective assay of the system is essential to recognizing and understanding its abnormalities. In this study, 18 healthy subjects and 32 patients with chronic obstructive pulmonary diseases (COPD) were examined by technetium-99m-DTPA aerosol scintigraphy. Monitoring was performed by visual inspection (cinescintigraphy) and quantitative analysis. The mucociliary clearance rates of 18 healthy subjects and 32 COPD patients were 3.89 +/- 0.92 mm/min and 1.32 +/- 0.59 mm/min respectively. Statistical analysis indicated that the airway clearance rate and mucociliary clearance rate of COPD patients were significantly lower than those of normal subjects (P < 0.01). The method of assay reported here is simple and objective. It has not only the advantage of visual inspection and quantitative analysis, but also the potential usefulness in studying other bronchial diseases and evaluating therapeutic effectiveness of drugs.

Adult↗
PubMed2002

[Study on the biological character of liposome-mediated 99m-technetium labeled antisense oligonucleotide for c-myc mRNA].

OBJECTIVE: To probe the biological character of liposome-mediated 99m-technetium-labeled antisense oligonucleotide of c-myc mRNA, and lay the foundations for clinical research on antisense image or treatment. METHODS: Antisense, sense and scrambled oligonucleoyide, each containing 15 bases, were synthesized elsewhere. The rates of liposome-entrapped 99mTc-DNA and 99mTc-DNA combination with plasma protein were tested through trichloroacetic acid precipitation. BALB/c mice were used to test the biodistribution in vivo, and rabbits were used to investigate the pharmacokinetics characters. RESULTS: Their rates of combination with plasma protein ranged from 34.81% to 70.53%. Reticuloendothelial system played an important role in the biodistribution; stomach, blood and intestines were less important; other tissues accumulated the least of the liposome-mediated 99mTc-labeled c-myc oligonucleotides. The pharmacokinetics of liposome-entrapped 99mTc-DNA fitted the open dithecal model. Their distribution (t1/2 alpha) half time was about 2 to 5 minutes, and clearance (t1/2 beta) half time about 100 to 150 minutes. Plasma clearance was smaller than 2 ml/min. CONCLUSION: The rate of 99mTc-DNA combination with plasma protein was high. The biological half time of liposome-mediated 99mTc-DNA was proper. Plasma clearance was high. So liposome-mediated 99mTc-DNA is a potential kind of radioactive agent.

Animals↗