Safety and Efficacy Study of Pulsed Electric Field (PEF) Therapy in Patients With Advanced or Unresectable Esophageal Squamous Cell Carcinoma

Inclusion criteria

• Aged 20 years or older when signing the informed consent form.
• Able to provide written informed consent, and understand and follow the study requirements and assessment schedule.
• Screening period tumor patients ECOG performance status score of 0 or 1.
• Laboratory test data within 7 days before the planned PEF treatment date during the screening period must meet the following standards.

• Neutrophil count (ANC) ≥1500 cells/mm3
• Platelet count ≥100,000 cells/mm3
• Hemoglobin ≥9 g/dL or ≥5.6 mmol/L
• Serum total bilirubin ≤ 1.5 x ULN.
• Females of childbearing potential must have a negative serum pregnancy test at screening and be willing to undergo additional pregnancy testing during the study.

Exclusion criteria

• Subjects with active respiratory tract infection who need antibiotic or antiviral treatment;
• Patients with locally advanced ESCC whose tumors can be surgically removed by the investigator or can be potentially cured by radical chemoradiotherapy according to the judgment of local investigators.
• Patients with esophageal lesions that severely invade adjacent organs (esophagus/bronchus or esophagus/aorta) and are assessed as high-risk esophageal leakage/fistula by the investigator.
• Evidence of complete esophageal obstruction that is not suitable for treatment, and gastroscopy cannot be performed.
• Patients with a history of esophageal stent implantation for esophageal obstruction;
• Patients with a history of gastrointestinal bleeding in the past 4 weeks, or gastroscopy indicates a high risk of tumor ulcer bleeding.
• Patients with obstruction caused by anastomotic stenosis without esophageal primary lesions after previous esophageal cancer surgery.
• Patients with active leptomeningeal disease or brain metastasis.
• Any active malignant tumor within 5 years before screening.
• Subjects have undergone metal implantation surgery such as esophageal stents and airway stents. Or the patient has an implantable cardioverter-defibrillator, pacemaker or other implantable electronic device.
• Patients with positive HIV test.
• Subjects are currently participating in other research clinical trials;
• Subjects who are considered by the investigator to have other high-risk conditions and are not suitable for gastroscopy and surgery;
• Subjects who have adverse events that have not yet returned to baseline or stable levels due to previous anti-tumor treatment, except for adverse events that do not pose safety risks (such as hair loss and abnormal values of specific laboratory tests)