14. Guidelines for Intratumoral Injection of Chlorine Dioxide in Soft Tissue Sarcoma

14.1 Indications

• 14.1.1 Located in connective tissue, subcutaneous tissue, other soft tissues, peripheral nerves, or within the retroperitoneum or mediastinum.

• 14.1.2 Unsuitable for or unwilling to undergo surgery.

• 14.1.3 Recurrence after surgery or chemo/radiotherapy.

• 14.1.4 No active diabetes, tuberculosis, or chronic hepatitis.

• 14.1.5 Normal bleeding and clotting times.

14.2 Contraindications

• 14.2.1 Severe cachexia.

• 14.2.2 Active diabetes, tuberculosis, or chronic hepatitis.

• 14.2.3 Platelet count < 60×10⁹/L.

14.3 Puncture Needle and Auxiliary Instruments

• Use 23G×15.0 cm, 25G×9.0 cm, 20G×9.0 cm, or 22G×9.0 cm puncture needles, a high-pressure syringe, ultrasound or CT machine.

14.4 Pre-treatment Preparation

• 14.4.1 Complete necessary examinations:

  • Routine blood, urine, and stool tests.

  • Liver, kidney function, and biochemical tests.

  • Chest CT, abdominal ultrasound, and relevant CT or ultrasound.

  • Peripheral blood T lymphocyte subsets (CD4, CD8).

  • ECG.

• 14.4.2 Discuss the procedure with the patient, obtain consent, addressing potential complications and precautions.

• 14.4.3 Administer intramuscular injections of butorphanol 0.1g or morphine 10mg, antihemorrhagic agent 1KU, ondansetron 4mg, and optionally diazepam 5–10mg, 15 minutes before treatment. Pediatric patients may require anesthesia assistance.

14.5 Treatment Procedure

• Depending on the tumor location, use ultrasound (abdomen, pelvis, or limbs) or CT (chest, abdomen, or pelvis) guidance.

• 14.5.1 Disinfect the puncture_site skin, wear sterile gloves, and use a sterile drape.

• 14.5.2 Post-anesthesia, stabilize the skin, insert the needle into the tumor center, and inject chlorine dioxide solution. For tumors ≤4 cm, use a single-point injection with a dose of 30% of the tumor volume (ml); for tumors >4 cm, use multi-point injections based on tumor segment (cm).

• 14.5.3 Monitor drug distribution within the tumor via ultrasound or CT and stop when saturation is achieved.

• 14.5.4 Remove the needle, cover the site with sterile gauze, and secure with tape.

• 14.5.5 Observe the patient for 10–15 minutes before returning them to the ward.

14.6 Post-treatment Care

• 14.6.1 During the first 1–3 days, monitor for redness, ulceration, pain, or fever. Provide anti-infection and symptomatic treatment if needed.

• 14.6.2 Check blood count and liver and kidney function on the 3rd and 7th days post-treatment.

14.6.3 For additional treatments, allow a 7-day interval. At the end of the treatment cycle, assess peripheral blood T lymphocyte subsets (CD4, CD8) to evaluate immune function.