Radioimmunoguided surgery

Radioimmunoguided Surgery (RIGS) is a surgical technique that combines the use of radiolabeled antibodies with a gamma detection probe to identify and remove cancerous tissues during surgery. This method is particularly useful in the treatment of certain types of cancers, such as colorectal cancer, where it can help in the precise localization and excision of tumors and metastatic disease that might not be detectable through conventional surgical methods or imaging techniques.

Overview

Radioimmunoguided surgery involves the administration of a radiolabeled monoclonal antibody that targets specific tumor-associated antigens. After the administration of the radiolabeled antibody, the patient undergoes surgery where a handheld gamma probe is used to detect the radiation emitted by the radiolabeled antibodies. This allows the surgeon to identify and remove tumor tissues with greater accuracy, potentially leading to improved surgical outcomes and reduced recurrence rates.

Procedure

The RIGS procedure involves several key steps:

1. Preparation and Administration of Radiolabeled Antibody: A monoclonal antibody that targets a specific antigen present on the tumor cells is labeled with a radioactive isotope. This radiolabeled antibody is then administered to the patient several days before the surgery.
2. Detection of Radiolabeled Tumor Cells: During surgery, the surgeon uses a handheld gamma detection probe to identify areas within the surgical field that emit radiation, indicating the presence of radiolabeled tumor cells.
3. Surgical Excision: Guided by the gamma probe, the surgeon can more accurately determine the margins of the tumor and remove both the primary tumor and any metastatic disease that has been labeled by the radiolabeled antibody.

Applications

RIGS has been primarily used in the treatment of colorectal cancer, but its application has also been explored in other types of cancer, including ovarian cancer, prostate cancer, and pancreatic cancer. The technique is particularly valuable in cases where tumors are difficult to detect and delineate through conventional imaging or during surgery.

Advantages

The main advantages of radioimmunoguided surgery include:

• Improved accuracy in identifying tumor margins, leading to more precise surgical excision.
• The ability to detect and remove micrometastases that might not be visible or palpable during surgery.
• Potential reduction in the rate of tumor recurrence and improved patient survival.

Limitations

Despite its benefits, RIGS also has limitations:

• The success of RIGS depends on the availability of a suitable monoclonal antibody that targets a specific antigen present on the tumor cells.
• There is a risk of radiation exposure to the patient and surgical team.
• The technique requires specialized equipment and training.

Future Directions

Research is ongoing to identify new tumor-associated antigens and develop corresponding radiolabeled antibodies to expand the application of RIGS to other types of cancer. Additionally, advancements in imaging technology and the development of more sensitive gamma probes may further enhance the effectiveness and safety of RIGS.

See Also

• Monoclonal antibody therapy
• Gamma probe
• Surgical oncology
• Nuclear medicine