# Compliance and Quality of Endoscopic Tattooing in Colorectal Cancer: A Retrospective Audit

## TL;DR

This study found that endoscopic tattooing for colorectal cancer is often not done or poorly documented, especially for tumors not visible on CT scans, which could affect surgical outcomes.

## Contribution

The study provides a detailed audit of endoscopic tattooing compliance and quality in colorectal cancer care, highlighting gaps in practice for CT-invisible lesions.

## Key findings

- Only 72% of mandatory lesions were tattooed at the initial colonoscopy.
- 40.1% of lesions were not visible on CT imaging, but repeat tattooing was performed in only 9 of 16 such cases.
- Adequate documentation of tattooing details was recorded in just 41.4% of cases.

## Abstract

Background

Colonoscopy is integral to the diagnosis and staging of colorectal cancer. Endoscopic tattooing enables accurate intraoperative localisation of malignant lesions, particularly when lesions are not visible on cross-sectional imaging. Despite established local guidelines, variability in tattooing practice and documentation persists, potentially affecting surgical planning and outcomes.

Objectives

This study aims to assess compliance with local endoscopic tattooing guidelines for colorectal cancer and evaluate the quality and consistency of current practice.

Methodology

A retrospective audit was conducted over a 12-month period (February 2019 to February 2020). Data were collected using multidisciplinary team (MDT) lists and extracted from colonoscopy reports, operative notes, and imaging records for 231 patients with colorectal cancer. Data were entered into a password-protected Microsoft Excel (Microsoft Corporation, Redmond, Washington) file and cross-checked for completeness and accuracy. Statistical analysis was performed using IBM SPSS Statistics for Windows, Version 29 (Released 2023; IBM Corp., Armonk, New York), and results were summarised using descriptive statistics and presented in tabular format. Findings were assessed against local trust guidelines and interpreted in the context of relevant literature.

Results

Of 142 lesions where tattooing was mandatory, only 102 (72%) were tattooed at the index colonoscopy. Fifty-seven lesions (40.1%) were not visible on CT imaging. Among non-tattooed lesions, 16 were CT-invisible; however, only nine underwent repeat endoscopic tattooing prior to surgery. Documentation quality was suboptimal, with adequate tattooing details recorded in only 41.4% of cases. These findings indicate inconsistent adherence to recommended practices, particularly in cases where accurate lesion localisation is most critical.

Conclusion

Compliance with local endoscopic tattooing guidelines was suboptimal, with significant deficiencies in both implementation and documentation. Inadequate tattooing and poor recording may hinder intraoperative localisation, particularly for CT-invisible tumours, potentially affecting surgical efficiency and outcomes. Targeted endoscopist education, standardised documentation proformas, and system-level interventions are required to improve compliance. These findings suggest that inadequate tattooing and poor documentation are most prevalent in lesions not visible on CT, where accurate endoscopic localisation is crucial for surgical planning. A repeat audit is recommended to evaluate the effectiveness of these measures and ensure sustained improvement in clinical practice.