Detection of pseudomyxoma peritonei by radioimmunohistochemistry and radioimmunoscintigraphy
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Culture and Imaging of Ex Vivo Organotypic Pseudomyxoma Peritonei Tumor Slices from Resected Human Tumor Specimens
Published on: December 9, 2022
K J Kairemo1, A P Jekunen, S Bondestam
1Dept. of Oncology, Helsinki University Central Hospital, Finland.
Abstract:
Pseudomyxoma peritonei (PP) is a local slowly progressing disease with typical abdominal swelling. Treatment is uneffective and the long-term prognosis is poor. Conventional radiology provides usually only a delineation of low density area relating gelatinous masses accumulating in the peritoneal cavity. In this study, immunohistochemistry based on digital quantitative autoradiography utilizing radiolabelled monoclonal antibody B72.3 (MoAb) recognizing TAG-72 antigen on epithelial carcinomas was used for diagnosis of pseudomyxoma (7 patients). The PP patients were studied with radioiodinated I-131-labeled MoAb after intravenous (2 patients) and intraperitoneal (7 patients) injections. Radioactivities of MoAbs varied considerably in the tumors. Both intra- and extracellular staining pattern was observed by immunohistochemistry. Gamma imaging at 1, 3, 7 and 14 days after i.v. injection (2 patients) revealed targeting of all known lesions. The intraperitoneally injected MoAb (7 patients) retained long time in the peritoneal cavity, specific tumour targeting was seen up to 16 days by an antibody-SPECT, while maximum blood radioactivity was measured between 8-12 hrs. Radiolabelled B72.3 MoAb recognizing TAG-72 antigen is also present within pseudomyxoma cells. It can be used for radioimmunohistochemistry of PP. Accurate imaging of PP is possible by MoAb suggesting earlier diagnosis and more accurate location of residual disease after operations, and evaluating treatment response. Estimated tumour dose for intraperitoneal tumour (MIRD formalism) was 13 mGy/MBq. This indicates that the radioiodinated B72.3 antibody can be used for in vivo targeting and therapeutic applications of intraperitoneal pseudomyxoma.
Insights
Pseudomyxoma peritonei (PP) diagnosis and treatment can be improved using radiolabeled B72.3 monoclonal antibody (MoAb). This antibody targets TAG-72 antigen, enabling accurate imaging and potential therapeutic applications for this rare abdominal disease.
Area of Science:
- Oncology
- Nuclear Medicine
- Immunohistochemistry
Background:
- Pseudomyxoma peritonei (PP) is a rare abdominal malignancy with poor prognosis and limited treatment options.
- Conventional radiology often provides only low-density area delineation, lacking specificity for gelatinous masses.
- Effective diagnostic and therapeutic strategies for PP remain a significant clinical challenge.
Purpose of the Study:
- To evaluate the utility of radiolabeled monoclonal antibody B72.3 (MoAb) for the diagnosis and imaging of pseudomyxoma peritonei (PP).
- To assess the targeting capabilities and biodistribution of I-131-labeled MoAb B72.3 in PP patients.
- To explore the potential of MoAb B72.3 for both diagnostic imaging and therapeutic applications in PP.
Main Methods:
- Immunohistochemistry and digital quantitative autoradiography utilizing radiolabeled MoAb B72.3 targeting TAG-72 antigen.
- Intravenous and intraperitoneal administration of I-131-labeled MoAb B72.3 in 9 PP patients.
- Gamma imaging and antibody-SPECT were performed at various time points post-injection to assess MoAb distribution and tumor targeting.
Main Results:
- Radioactivities of MoAbs varied within tumors, with both intra- and extracellular staining observed.
- Gamma imaging demonstrated successful targeting of known lesions after intravenous injection.
- Intraperitoneal MoAb showed prolonged retention in the peritoneal cavity with specific tumor targeting up to 16 days, while blood radioactivity peaked between 8-12 hours.
Conclusions:
- Radiolabeled B72.3 MoAb effectively targets TAG-72 antigen in pseudomyxoma peritonei cells, enabling accurate imaging.
- The antibody's biodistribution suggests potential for earlier diagnosis, precise localization of residual disease, and evaluation of treatment response.
- Radioiodinated B72.3 antibody holds promise for in vivo targeting and therapeutic applications in intraperitoneal pseudomyxoma.
