• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.541-547
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• 1996

The previous monoclonal antibody labeling method for bone marrow immunoscintigrapy was complicated and laborious for clinical application. Also it showed a relatively low labeling efficiency. To improve this procedure, we compared several direct labeling methods of $^{99m}Tc$. 1) The labeling efficiency in the method using gluconate as a transchelator was low (40-70%), but immunoscintigraphy using this radiotracer produced a clear image. 2) To improve labeling efficiency, ${\beta}$-mercaptoethanol was removed after reduction. The labeling efficiency was improved up to 70-80%, but the radioactivity of the blood pool was high. 3) The higest labeling efficiency (>90%) and best quality images could be obtained by using MDP as a transchelating agent. It did not require additional procedures for separation of labeled antibodies. The immunoreactivity of this antibody was 60%. Residual MDP which can be taken up by the bone could be removed by PD-10 column. The reduced antibodies were stable with a high labeling efficiency (>90%) for up to 47 days by deep freezing. We concluded that the improved procedure for $^{99m}Tc$ labeling of anti-NCA-95 monoclonal antibody using MDP as a transchelating agent will be a simple and useful method for clinical application.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.344-353
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• 1998

Purpose: The purpose of this study was to evaluate the diagnostic accuracy of Tc-99m labeled antigranulocyte antibody immunoscintigrapy in the diagnosis of osteomyelitis and compare with the results of triphasic bone scan. Materials and Methods: The study population was 39 patients (22 male, 17 female) who had uncertain diagnoses of osteomyelitis. Fifteen patients had history of orthopedic surgery, and 5 had previous fracture. One milligram of monoclonal antibody against NCA-95 was labeled with 370 MBq of Tc-99m, injected intravenously, and 4 hour images were obtained. Triphasic bone scan images were obtained in 30 patients. The final diagnosis was confirmed by bacteriologic culture, biopsy or long term clinical follow up. Results: Twenty one patients were confirmed to have osteomyelitis (1 acute, 20 chronic). Eighteen patients were without osteomyelitis. Antigranulocyte antibody immunoscintigraphy had a sensitivity of 71% (15/21), and a specificity of 89% (16/18), while the sensitivity and specificity of triphasic bone scan was 93% (13/14) and 38% (6/16), respectively. Antigranulocyte antibody scan showed higher specificity of 100% (11/11) in comparison with 33% (3/9) of triphasic bone scan in patients with history of orthopedic surgery or fracture. Conclusion: Antigranulocyte antibody immunoscintigraphy is more specific than that of triphasic bone scan and may be helpful in patients with history of surgery or fracture. However, sensitivity is lower than triphasic bone scan in the detection of chronic osteomyelitis.

• The Korean Journal of Nuclear Medicine
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• v.36 no.5
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• pp.298-305
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• 2002

Purpose: Bone marrow scintigraphy has been used to evaluate the status of bone marrow in various hematologic disorders. We have analyzed the peripheral distribution pattern and central uptake ratio of bone marrow using anti-NCA-95 monoclonal antibody and the their correlation in patients with various hematologic malignancy. Materials and Methods: Bone marrow immunoscintigraphy was performed using Tc-99m anti-granulocyte monoclonal mouse antibody BW 250/183. Fifty patients were classified into four groups; 11 with acute myelogenous leukemia, 12 with acute lymphocytic leukemia, 15 with lymphoma and 12 with myelodysplastic syndrome. The extension of peripheral bone marrow was categorized into four grades: I, II, III and IV. The activity of central bene marrow was expressed as sacroiliac uptake ratio. Results: The patient's number was 4 in grade I, 27 in grade II, 15 in grade III and 4 in grade IV according to extension of peripheral bone marrow. The extension of peripheral bone marrow was marked (58% in grade III and IV) in myelodysplastic syndrome and acute lymphocytic leukemia and mild (93% in grade I and II) in lymphoma. Sacroiliac uptake ratio was highest ($8.5{\pm}4.0$) in myelodysplastic syndrome and lowest ($5.9{\pm}3.6$) in acute myelogenous leukemia, but not significantly different among four patient groups (p>0.05). Sacroiliac uptake ratio of whole patients was significantly different among four grades (p=0.003), but there was not correlated between grade of peripheral bone marrow and sacroiliac uptake ratio (r=0.05). Conclusion: The pattern of peripheral bone marrow extension and activity of central hemopoietic marrow were not specific to the disease entities. Response of hemopoietic bone marrow may be evaluated on both peripheral and central bone marrow in patients with hematologic malignancy.

• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.89-97
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• 1994

Although bone scan is a highly sensitive test for detecting bone metastasis, its findings are often limited in specificity and cannot be used for assessing the bone marrow. Bone marrow scintigraphy may provide useful information but previous experience with radiolabelled colloid has been disappointing. Recently, $^{99m}Tc$ labeled anti-granulocyte monoclonal antibody (anti-NCA-95 MAb) has been introduced as a new bone marrow imaging agent. To evaluate the usefulness of $^{99m}Tc$ anti-NCA MAb bone marrow scans for detecting skeletal metastasis, bone marrow scans of 44 malignant tumor patients were evaluated and compared with bone scan findings. Bone scan showed abnormal lesions in 26(59%) cases, and 18 of these patients also had an abnormal bone marrow scan. Seven of the 8 patients who had normal bone marrow scan despite bone scan lesions were confirmed to be free from metastasis. There was one case with a marrow defect despite normal bone scan but the presence of metastasis was not determined due to loss of follow up. Bone scan demonstrated a total of 64 lesions while bone marrow scan showed 38 lesions. Fifty percent (32/64) of the bone scan lesions had matching marrow defects while the remaining 50% did not. Most of these non matched lesions were suggested to be nonspecific lesions such as rib fractures or degenerative change. Meanwhile bone marrow scan was able to detect 6 new lesions not detected by bone scan, bit metastasis in each lesion was not confirmed. Bone marrow scan was also helpful in assessing equivocal bone scan lesions to be of metastatic nature in 10 patients by demonstrating a matched marrow defect. Thus $^{99m}Tc$ anti-NCA MAb bone marrow scan can help exclude metastasis in patients with nonspecific bone scan lesions and may be able to detect metastatic lesions not seen with bone scan. It appears useful as a complementary study to bone scan in evaluating malignant tumor patients.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.516-524
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• 1998

Purpose: Radiolabeled CEA79.4 antibody has a possibility to be used in radioimmunoscintigraphy or radioimmunotherapy of cancer. We investigated the in vitro properties and biodistribution of CEA79.4 antibody labeled with Re-188 or Tc-99m. Materials and Methods: CEA79.4 was reduced by 2-mercaptoethanol to produce-SH residue, and was labeled with Re-188 or Tc-99m. For direct labeling of Tc-99m, methylene-diphosphonate was used as transchelating agent. CEA79.4 in 50 mM Acetate Buffered Saline (ABS, pH 5.3) was labeled with Re-188, using stannous tartrate as reducing agent. In order to measure immunoreactivity and the affinity constant of radiolabeled antibody, cell binding assay and Scatchard analysis using human colon cancer cells SNU-C4, were performed. Biodistribution study of labeled CEA79.4 was carried out at 1, 14 and 24 hr in ICR mice. Results: Labeling efficiencies of Tc-99m and Re-188 labeled antibodies were $92.4{\pm}5.9%$ and $84.7{\pm}4.6%$, respectively, In vitro stability of Tc-99m-CEA79.4 in human serum was higher than Re-188-CEA79.4. Immunoreactivity and affinity constant of Tc-99m-CEA79.4 were 59.2% and $6.59{\times}10^9\;M^{-1}$, respectively, while those of Re-188-CEA79.4 were 41.6% and $4.2{\times}10^9\;M^{-1}$, respectively. After 24 hr of administrations of Re-188 and Tc-99m labeled antibody, the remaining antibodies in blood were 6.32 and 9.35% ID/g respectively. The biodistribution of each labeled antibody in other organs was similar because they did not accumulate in non-targeted organs. Conclusion: In vitro properties and biodistribution of Re-188-CEA79.4 were similar to those of Tc-99m-CEA79.4. It appears that Re-188-CEA79.4 can be used as a suitable agent for radioimmunotheraphy.