7．Guidelines for Intratumoral Injection of Chlorine Dioxide in Gastric Cancer

7.1 Indications

• 7.1.1 Early or mid-stage gastric cancer that is inoperable or where the patient refuses surgery.

• 7.1.2 Advanced gastric cancer with metastasis; local chlorine dioxide treatment can be applied to both the gastric tumor and metastatic lesions.

• 7.1.3 Recurrence of gastric cancer after surgery or after chemoradiotherapy.

• 7.1.4 Normal bleeding and clotting times, with normal prothrombin time and coagulation parameters.

7.2 Contraindications

• 7.2.1 Large cancerous ulcers in the stomach with signs of perforation.

• 7.2.2 Platelet count < 60×10⁹/L.

• 7.2.3 Severe anemia with Hb < 60g/L.

• 7.2.4 Gastric cancer with significant ascites or cachexia.

• 7.2.5 Patients unable to tolerate endoscopic procedures.

7.3 Pre-treatment Preparation

• 7.3.1 Complete necessary examinations:

  • Routine blood, urine, and stool tests, including occult blood in stool.

  • Liver and kidney function tests, peripheral blood T lymphocyte subsets (CD4, CD8).

  • Abdominal ultrasound and upper gastrointestinal barium X-ray.

  • Tumor markers: CEA, CA72-4, CA19-9.

  • ECG.

• 7.3.2 Conduct a pre-procedure consultation and obtain treatment consent. Address concerns about endoscopic treatment, discussing potential complications like fever, localized pain, bleeding, gastric perforation, and related peritonitis.

• 7.3.3 Administer intramuscular injections of 10mg anisodamine, 0.1g butorphanol, and 1KU of antihemorrhagic agent 15 minutes before treatment. Use oral anesthetic (10ml of endoscopic lubricating gel) to anesthetize the oropharynx and esophageal mucosa.

7.4 Treatment Procedure

• 7.4.1 Position the patient on their left side with the head slightly forward.

• 7.4.2 Insert the endoscope through the mouth to the gastric lesion. Check for any mucosal congestion, edema, or ulceration. If there is a narrowing that prevents the scope from passing, choose an injection site on the proximal tumor and inject chlorine dioxide solution in divided doses using a puncture needle through the scope’s treatment channel. If the scope passes through, inject at multiple points on the tumor, using a volume equal to 30% of the tumor size (ml) per point.

• 7.4.3 After the injections, remove the endoscope and observe the patient for 10–15 minutes before returning them to the ward.

7.5 Post-treatment Care

• 7.5.1 Allow intake of liquid or semi-liquid foods 2 hours after treatment.

• 7.5.2 Administer antibiotics and antacid medications intravenously.

• 7.5.3 Monitor for fever, abdominal pain, nausea, vomiting, and manage symptoms promptly.

• 7.5.4 Repeat blood tests, fecal occult blood, and liver and kidney function tests every 3-4 days.

• 7.5.5 If further treatments are necessary, schedule them approximately one week apart. Before discharge, conduct peripheral blood T lymphocyte subset (CD4, CD8) tests, gastric barium X-ray, and chest and abdominal CT to assess immune function and disease progression.

7.6 Clinical Experience and Considerations

• 7.6.1 Bloating, belching, or coughing: Encourage the patient to sit up and expectorate saliva post-treatment. Suggest attempting liquid food 2 hours later as analgesics may still affect the swallowing reflex, preventing choking or aspiration pneumonia.

• 7.6.2 Throat pain or foreign body sensation: Discomfort may occur within 1-2 days post-treatment. Consider iodine lozenges or Scleroglucan lozenges and use mannitol to reduce mucosal edema if necessary.

• 7.6.3 Ensure the patient fasts for at least 8 hours before treatment. Fully anesthetize the oropharynx and esophageal mucosa with endoscopic gel before injecting, and inject in increments to avoid acute inflammatory obstruction of the tumor.

• 7.6.4 Thoroughly communicate with the patient pre-procedure, position them correctly, and seek their cooperation for a successful treatment.