# Case Report: Is the isolated bone change in advanced colorectal cancer necessarily malignant metastasis?

## TL;DR

This case report shows how radiation osteitis can be mistaken for cancer spread in the bone, and how careful evaluation can avoid unnecessary biopsies.

## Contribution

The paper presents two cases that demonstrate non-invasive methods to distinguish radiation osteitis from bone metastasis in colorectal cancer.

## Key findings

- Radiation osteitis can mimic bone metastasis on imaging in advanced colorectal cancer.
- Comprehensive evaluation using imaging, lab tests, and MDT consultations can confirm RO without biopsy.
- Accurate diagnosis of RO helps avoid unnecessary treatments and improves patient care.

## Abstract

Radiation osteitis (RO) is a bone-related complication following radiotherapy (RT), often characterized by atypical imaging features. It is challenging to distinguish RO from early bone metastasis (BM), potentially leading to inappropriate treatment. Therefore, establishing reliable diagnostic criteria for accurately identifying RO is essential for improving treatment outcomes in advanced colorectal cancer (CRC).

Two cases of advanced CRC patients with atypical isolated bone changes on imaging are presented. Both patients received standard chemotherapy and radiotherapy after surgery. Through comprehensive imaging studies, laboratory evaluations, and multidisciplinary team (MDT) consultations, the diagnosis of RO was confirmed instead of BM, thereby avoiding the need for an invasive pathological biopsy.

This case report highlights imaging features of RO and provides valuable insights into differentiating RO from BM by integrating medical history, laboratory findings, and imaging results.