4 tests to confirm gastric cancer bone metastasis

The patient is a 57-year-old male. He was diagnosed with advanced gastric cancer four months ago and underwent a total gastrectomy. After two chemotherapy sessions, he developed lumbar and cervical spine pain. What happened?

According to the patient's condition, it is considered to be a phenomenon of bone metastasis in the late stage of gastric cancer, and there is a possibility of further development.

Gastric cancer is a common malignant tumor of the digestive system. Due to its high malignancy, it may metastasize and spread throughout the body in the early stage. The metastasis of gastric cancer is generally through the blood circulation. Cancer cells can metastasize to the spine and grow, causing low back pain accompanied by radiating soreness, swelling, and numbness in the lower limbs.

Commonly used tests for gastric cancer bone metastasis:

1. Bone scan (bone ECT) is an early diagnostic method

In the diagnosis of bone metastasis, bone ECT has high sensitivity. When bone metabolism, especially bone regeneration, accounts for only 5%, abnormal concentration of radioisotopes can be seen in the diseased bone, and bone changes can be shown 3 to 6 months before positive changes on X-ray films. Therefore, it can be used as an early diagnosis method for bone metastasis.

2. Bone biopsy if necessary

For hyperplastic bone metastases, bone biopsy should be performed to confirm the diagnosis if necessary. For smaller bone metastases, it can also be performed under the guidance of CT or MRI.

3. X-ray examination is the most economical and most commonly used

X-ray examination is less sensitive than bone scanning for gastric cancer bone metastasis but has higher specificity. It is the most economical and most commonly used method for diagnosing bone metastasis. X-ray films can generally only be displayed when the decalcification rate at the lesion site is greater than 30% to 50% or new bone is formed. Most bone metastases are osteolytic changes, and X-rays show destruction of the bone cortex; while osteogenic changes are mainly manifested by increased bone density on X-rays.

4. CT and MRI for final diagnosis

CT and MRI can detect lesions of 3 to 5 mm and confirm suspected bone metastases on bone scans. CT is more sensitive to changes in cortical bone than MRI, and has advantages in detecting bone metastases in the pelvic bones and shoulder joints. MRI has a 12.8% higher detection rate for bone metastases than plain X-rays and bone scans, and is more sensitive to bone marrow (where most bone metastases first appear) and bone marrow lesions.