5. Guidelines for Chlorine Dioxide Intratumoral Injection in Pancreatic Cancer

5.1 Indications

• 5.1.1 Applicable for cancers in all parts of the pancreas, including periampullary, distal bile duct, second part of the duodenum, and uncinate process cancers.

• 5.1.2 Patients with normal blood count and coagulation profiles.

• 5.1.3 Metastatic pancreatic cancer, whether in single or multiple tumors.

• 5.1.4 Patients with recurrent pancreatic cancer post-surgery or where surgery was unsuccessful.

• 5.1.5 Patients who refuse surgery despite surgical indications.

• 5.1.6 When systemic chemotherapy fails.

5.2 Contraindications

• 5.2.1 Periampullary cancer with duodenal obstruction, preventing oral intake.

• 5.2.2 Severe jaundice, ascites, and cachexia.

• 5.2.3 PLT < 60×10⁹/L.

• 5.2.4 Pancreatic cancer with diabetes or active pulmonary tuberculosis.

• 5.2.5 KPS ≤ 40.

5.3 Pre-Treatment Preparation

• 5.3.1 Conduct necessary tests, including routine blood, urine, and stool tests, liver, kidney, and heart functions, and tumor markers like CA199, CA50, CEA, CA724.

• 5.3.2 Conduct a pre-treatment discussion and obtain informed consent.

• 5.3.3 Administer 0.1g buclizine, 1 KU antifibrinolytic drugs or 1.0g phenethylamine, and 4-8mg ondansetron intramuscularly 15 minutes before treatment to prevent pain, bleeding, and vomiting.

• 5.3.4 For CT-guided procedures, have the patient drink 500ml of 1%-2% gastrografin solution before treatment.

5.4 Needles and Auxiliary Equipment

• 5.4.1 Puncture needles: 23G×15.0 cm or 25G×9.0 cm.

• 5.4.2 Use ultrasound or CT scanners and syringes for guidance.

5.5 Procedure

• 5.5.1 Use ultrasound or CT to locate the puncture site and measure the distance to the tumor center.

• 5.5.2 Disinfect the area, wear sterile gloves, and apply sterile drapes.

• 5.5.3 Administer local anesthesia with 2% lidocaine, stabilize the site, insert the needle into the tumor center using imaging for guidance.

• 5.5.4 Remove the needle core, attach the syringe, and slowly inject the chlorine dioxide solution. For tumors ≤4 cm, use a single-point injection at 30% of the tumor volume; for larger tumors, use multiple points with each point receiving 30% of that section's volume.

• 5.5.5 After injection, briefly pause, remove the needle, cover the site, and observe the patient for 5-10 minutes before returning to the ward.

5.6 Post-Treatment Care

• 5.6.1 Monitor for fever, local pain, eating difficulties, or signs of peritonitis.

• 5.6.2 For fever, administer compound aminopyrine barbiturate and dexamethasone; for pain, use morphine or buclizine orally or inject as needed.

• 5.6.3 Recommend a liquid or semi-liquid diet for 1-3 days post-treatment to prevent duodenal obstruction; administer antibiotics for peritonitis.

• 5.6.4 Schedule subsequent treatments 5-7 days apart. Assess immune and tumor status via T lymphocyte subset testing and imaging before discharge or one week after treatment.

5.7 Clinical Experience

• 5.7.1 CT-guided injections are recommended as they provide a clear tumor view.

• 5.7.2 Ensure precise needle placement to avoid gastrointestinal puncture; strive for a single successful puncture.

• 5.7.3 If pain occurs during injection, administer additional lidocaine before proceeding.

• 5.7.4 Follow dosage calculations strictly, without unnecessary adjustments.

• 5.7.5 Manage acute inflammation post-injection as acute pancreatitis, potentially using octreotide.