sodium-pertechnetate-tc-99m and Colorectal-Neoplasms

Biodistribution of chimeric mouse/human monoclonal antibody against non-specific cross-reacting antigen (chNCA Ab) was studied in athymic mice and patients with metastatic bone disease. 99mTc-chNCA Ab showed a high labelling efficiency, stability and also a high binding ratio to human granulocytes. Since NCA showed cross-reactivity with carcinoembryonic antigen (CEA), animal experiments showed that 99mTc-chNCA Ab was accumulated in the xenografted tumour which expressed CEA, suggesting the preserved immunoreactivity of labelled materials. In the clinical study, injected 99mTc-chNCA Ab formed a high molecular weight complex immediately after intravenous administration and was trapped mainly in liver. The first-phase plasma half-life was 6.4 +/- 1.1 min. None of the patients showed adverse reaction or human antimurine or anti-chimeric antibody in their serum. 99mTc-chNCA Ab demonstrated remarkably different biodistribution between patients and the animal model and showed different pharmacokinetics from other murine and chimeric Abs reported previously. For safety HPLC analysis should be performed before clinical radioimmunodetection or radioimmunotherapy by incubating radiolabelled MAb with human serum under strict conditions.

Topics: Aged; Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Bone Neoplasms; Cell Adhesion Molecules; Colorectal Neoplasms; Humans; Immunoconjugates; Male; Membrane Glycoproteins; Mice; Mice, Inbred BALB C; Mice, Nude; Middle Aged; Neoplasm Transplantation; Prostatic Neoplasms; Radioimmunodetection; Recombinant Fusion Proteins; Sodium Pertechnetate Tc 99m; Tissue Distribution

Topics: Colorectal Neoplasms; Doxorubicin; Drug Carriers; Erythrocyte Membrane; Glutaral; Humans; In Vitro Techniques; Liver Neoplasms; Male; Middle Aged; Sodium Pertechnetate Tc 99m

Topics: Adenoma; Cell Proliferation; Colorectal Neoplasms; Diagnosis, Differential; Humans; Hyperplasia; Indium Radioisotopes; Male; Middle Aged; Sodium Pertechnetate Tc 99m; Somatostatin; Technetium Tc 99m Sestamibi; Thyroid Gland; Thyroid Neoplasms; Tomography, Emission-Computed, Single-Photon

The anti-carcinoembryonic antigen (CEA) antibody, BW 431/26 (Scintimun CEA, Behringwerke, Marburg, Germany ) labeled with technetium pertechnectate (99mTc), is an intact immunoglobulin G1, monoclonal antibody that has been used to image colorectal cancer. Planar and SPECT images of chest, abdomen and pelvis were performed at 10 minutes, 4-6 and 18-24 hours after the intravenous antibody injection. 44 patients were studied and the pathological antibody concentration localization by radioimmunoimaging (RI) were correlated with surgical, clinical and other imaging modality findings to validate the RI. The RI was positive in 29 patients and negative in the other 15 patients. The CEA and CA 19.9 were elevated in the serum of some patients with primary tumors or recurrence. The HAMA were determined in all the patients before and after the RI.

Topics: Adult; Aged; Animals; Antibodies, Monoclonal; Antigens, Neoplasm; CA-19-9 Antigen; Carcinoembryonic Antigen; Carcinoma; Colonic Neoplasms; Colorectal Neoplasms; Evaluation Studies as Topic; Female; Humans; Male; Mice; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local; Neoplasm, Residual; Predictive Value of Tests; Radioimmunodetection; Rectal Neoplasms; Sigmoid Neoplasms; Sodium Pertechnetate Tc 99m; Species Specificity; Tomography, Emission-Computed, Single-Photon

The immunoscintigraphic detection of tumour foci less than 1 cm in diameter fails even with single photon emission tomography (SPET) owing to low contrast against background activity. In an attempt to improve detection of macroscopically invisible tumour spread, intraoperative scintimetry (IOSM) with a hand-held gamma-probe was performed in addition to SPET 24-30 and 41-48 h after injection of the technetium-99m carcinoembryonic antigen (CEA MoA) on 12 patients with colorectal carcinoma and 3 patients with different neoplastic and inflammatory diseases. Tumour specimens were measured in vitro in a gamma well counter. For comparison, the presence and amount of CEA in the tumour cells were evaluated immunohistochemically. After modification, the gamma-probe originally designed for iodine-131 was 20 times more sensitive; activities of 99mTc located close to the collimator hole were measured with absolute sensitivity of 100 cps = 2.5 kBq 99mTc. The unfavourably high background activity affected both the in vitro and in vivo analysis: SPET results had been considered positive in 8 of 15 cases. In vitro tumour/non-tumour (t/nt) ratios greater than 2.0 were found in 4 cases. In vivo IOSM resulted in t/nt ratios greater than 2.0 in only 3 patients. In most cases, there was no coincidence of elevated t/nt ratios from the different methods. A correlation was derived between positive immunoscintimetric in vitro findings and immunohistochemically proven interstitial localization of CEA in tumor cells. In conclusion, the measurement technique of IOSM seems adequate, but clinical success will depend on a more specific enrichment of MoA in tumour tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Colorectal Neoplasms; Female; Humans; Intraoperative Care; Male; Middle Aged; Preoperative Care; Radioimmunodetection; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m; Tomography, Emission-Computed, Single-Photon

To estimate the radiation exposure to surgical personnel caused by intraoperative radioimmunoscintimetry, we measured dose rates at different distances from patients who had been injected with 950 MBq technetium-99m-labelled intact carcinoembryonic antigen (CEA)-specific antibodies (Szintimun CEA, Behring AG Marburg, FRG) for immunoscintigraphy 24 h earlier. At 0.05 m (corresponding to working positions during surgery) we found 2.0-16.0 microSv h-1 (average 6.4), which is similar to results for nuclear medicine staff. Thus, if radioimmunoscintimetry is to become a routine procedure, according to national regulations in some countries of the European Communities surgical personnel might be regarded as professionally exposed to radiation.

Topics: Colorectal Neoplasms; General Surgery; Humans; Intraoperative Care; Occupational Exposure; Radiation Dosage; Radiation Protection; Radioimmunodetection; Sodium Pertechnetate Tc 99m

Topics: Antibodies, Monoclonal; Carcinoembryonic Antigen; Colorectal Neoplasms; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

The monoclonal antibody PR1A3 against a normal colonic columnar cell surface antigen has been labelled with 99mTc and used for imaging colorectal cancer. High uptake in undifferentiated cancer is seen. The tumour to mucosa ratio was up to 63:1 and the percentage of the injected activity in the tumour up to 1.7 X 10(-2%)g-1. As 99mTc is continuously available in a Nuclear Medicine Department, on receipt of a request the study may be completed within 24 h enabling radioimmunoscintigraphy to be used routinely in the management of patients with colorectal cancer.

Topics: Adenocarcinoma; Antibodies, Monoclonal; Colorectal Neoplasms; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Using the intact monoclonal IgG1 anti-CEA antibody BW 431/26 (Behringwerke Marburg, FRG) labelled with 99mTc by a new labelling procedure (Schwarz method), 72 patients suspected of tumour recurrences (colorectal cancer, n = 59) and with rising serum carcinoembryonic antigen (CEA) levels were studied. Sixty-nine of 72 studies had a positive result by immunoscintigraphy of which 52 have since been proven histologically/clinically. In six patients only immunoscintigraphy revealed a tumour recurrence while all other diagnostic modalities were negative. Of 52 studies 46 were true positive (diagnostic sensitivity 88%). In this series there was one false positive result. About one-third of all patients injected with the antibody developed a human anti-mouse response (HAMA), but no severe side effects were seen even after four applications. For the follow-up of colorectal and other CEA positive adenocarcinomas this 99mTc-labelled monoclonal antibody seems to be very promising in patients with rising serum CEA, especially if conventional diagnostic imaging procedures remain negative.

Topics: Antibodies, Monoclonal; Carcinoembryonic Antigen; Colorectal Neoplasms; Follow-Up Studies; Humans; Radionuclide Imaging; Sodium Pertechnetate Tc 99m

Sixty-four patients operated for colorectal cancer comprise the study group. CEA and CA-19.9 markers were used. The antibodies were labelled with 131I, using for the scintigraphy 99mTc as well. Eighty eight metastatic foci were detected, 67 of them (76.1 per cent) confirmed by the surgeon: Of 55 pelvic localizations, surgically detected were 47 (85.5 per cent), of 24 in the abdominal cavity 15 (62.5 per cent) were confirmed and of 9 in the liver--only 5 (55 per cent). Radioimmunoassay more accurate in pelvic localizations, whereas echography and computer tomography were more precise in liver examination (83.3 per cent).

Topics: Adult; Aged; Antibodies, Monoclonal; Antigens, Tumor-Associated, Carbohydrate; Carcinoembryonic Antigen; Colorectal Neoplasms; Humans; Iodine Radioisotopes; Middle Aged; Neoplasm Metastasis; Neoplasm Recurrence, Local; Sodium Pertechnetate Tc 99m