9. Guidelines for Intratumoral Injection of Chlorine Dioxide in Breast Cancer

9.1 Indications

• 9.1.1 Breast cancer at any stage.

• 9.1.2 Recurrence after radical mastectomy or chemoradiotherapy.

• 9.1.3 Metastasis to the breast pectoralis or supraclavicular lymph nodes.

• 9.1.4 Distant organ metastasis from breast cancer.

• 9.1.5 Normal bleeding and clotting times.

9.2 Contraindications

• 9.2.1 Platelet count < 60×10⁹/L.

9.3 Pre-treatment Preparation

• 9.3.1 Complete pre-treatment examinations:

  • Blood count and coagulation tests.

  • Liver and kidney function tests.

  • Tumor markers: ER, PR, HER2, CA153, CEA.

  • Imaging: Mammography, breast ultrasound, abdominal and neck/axillary ultrasound, CT of the chest and brain.

  • Histopathological diagnosis.

• 9.3.2 Discuss the procedure and obtain consent, addressing possible complications such as fever, local skin ulcers, and pain.

• 9.3.3 Administer intramuscular injections of 0.1g butorphanol, 1KU antihemorrhagic agent, and 4-8mg ondansetron 15 minutes before treatment.

9.4 Puncture Needle and Auxiliary Equipment

• Use a 23G×15.0 cm or 25G×9.0 cm puncture needle, syringe, 10ml and 20ml syringes, and ultrasound or CT machine.

9.5 Treatment Procedure

• 9.5.1 Select the puncture site under ultrasound or CT guidance.

• 9.5.2 Disinfect the skin, wear sterile gloves, and cover with a sterile drape.

• 9.5.3 Use 2% lidocaine for local anesthesia, stabilize the puncture site with the left hand, and insert the needle into the tumor center with the right hand.

• 9.5.4 Withdraw the needle core, connect a high-pressure syringe, and slowly inject chlorine dioxide solution under ultrasound or CT guidance. For tumors ≤4 cm, use single-point injection based on 30% of the tumor volume (ml). For tumors >4 cm, use multi-point injections with the same volume calculation.

• 9.5.5 After injection, remove the needle, cover with sterile gauze, and secure with tape.

• 9.5.6 Observe for 5–10 minutes post-procedure and then send the patient back to the ward.

9.6 Post-treatment Care

• 9.6.1 Monitor for redness, swelling, ulceration, pain, fever, and fatigue, and treat any complications promptly.

• 9.6.2 Check blood counts twice weekly, monitor WBC and PLT changes. Use granulocyte colony-stimulating factor if WBC < 4.0×10⁹/L, interleukin-11 for PLT < 80×10⁹/L, and oral iron supplements for Hb < 80g/L; transfusion if Hb < 60g/L.

• 9.6.3 Conduct weekly liver and kidney function tests to check for any damage.

• 9.6.4 After one treatment cycle, assess peripheral blood T lymphocyte subsets (CD4, CD8), and relevant molecular biological markers and genes.

9.7 Experience and Complications Management

• 9.7.1 For local redness, heat, and pain, provide anti-infective treatment and magnesium sulfate wet compress to reduce swelling.

• 9.7.2 For exudation or ulceration, apply ozone treatment locally to keep the wound clean and dry.

9.7.3 Skin ulceration post-treatment can occur due to drug leakage or shallow puncture. Choose puncture points near the base to avoid irritating the skin. Post-treatment, apply a local wet compress to reduce congestion and edema.