Question

Techniques for margin assessment after tumor resection.

Hint:

Margin assessment is essential in oncologic surgery, with techniques like frozen section and permanent section analysis being critical to ensuring complete tumor removal and reducing recurrence risk.

Answer 1

Margin assessment after tumor resection is a crucial step in oncologic surgery to ensure complete tumor removal and reduce the risk of recurrence. The goal is to confirm that the resected tissue has no residual tumor cells at the surgical margin, which can be a potential source of local recurrence.
Step 1: Intraoperative Techniques:
- Frozen Section Analysis: During surgery, frozen section analysis is commonly performed. A portion of the resected tissue is rapidly frozen and stained, allowing pathologists to examine the margins for tumor cells. This technique enables immediate decision-making regarding additional tissue removal if cancerous cells are present at the margins.
- Touch Preparation: A touch preparation involves pressing the resected tissue against a slide, which is then stained for rapid evaluation. This technique is less common than frozen section but can be useful for quick margin evaluation.
Step 2: Postoperative Techniques:
- Permanent Section Analysis: After surgery, the tissue is sent for permanent sectioning, where the tumor and surrounding tissue are processed and examined under a microscope. This is the most definitive method for margin assessment, providing a clear evaluation of whether the resection was complete.
- Margins and Risk of Recurrence: The presence of tumor cells at the margin, especially if the tumor is within 1 mm of the margin, is associated with a higher risk of recurrence. Additional resection or adjuvant therapy may be required based on the findings.
Step 3: Imaging Techniques:
- Intraoperative Imaging: Techniques such as intraoperative ultrasound (IOUS) and positron emission tomography (PET) scans are used in some surgeries to provide real-time imaging of the tumor's boundaries, ensuring that the margins are clear. This can be particularly useful in abdominal or deep tissue surgeries.