A Multicenter, Prospective Single-arm Study of Multimodal Thermal Therapy Combined With Toripalimab and AG Chemotherapy in the Treatment of Advanced Pancreatic Cancer

• Multimodal Thermal Therapy (MTT) System (Device): The MTT system is a medical device that performs sequential ablation therapy. Treatment consists of initial cryoablation followed immediately by radiofrequency ablation (RFA) to achieve a synergistic thermal effect against the tumor.
• Toripalimab (Drug): Toripalimab is a humanized IgG4 monoclonal antibody against programmed death-1 (PD-1). It is administered via intravenous infusion at a standard dose according to the protocol to block the PD-1/PD-L1 pathway and enhance anti-tumor immunity.
• Gemcitabine and Nab-Paclitaxel (Drug): Gemcitabine combined with nab-paclitaxel (albumin-bound paclitaxel) is a standard chemotherapy regimen for advanced pancreatic cancer. Both drugs are administered via intravenous infusion according to the clinical protocol to inhibit cancer cell proliferation and division.

Primary outcomes

• Conversion success rate [From the start of treatment (Multimodal Thermal Therapy) until the evaluation of surgical conversion following at least 4 cycles of subsequent combination therapy, assessed up to 2 years]: Percentage of subjects achieving successful conversion among all enrolled subjects

Secondary outcomes

• Progression-Free Survival(RECIST 1.1) [From the start of treatment until documented disease progression or death, assessed up to 2 years]: Time from the start of treatment until disease progression (according to RECIST 1.1 based on enhanced abdominal/chest-abnormal CT or MRI every 6-8 weeks) or death from any cause, whichever occurs first.
• Recurrence-Free Survival [From the date of radical surgical resection until disease recurrence or death from any cause, assessed up to 2 years]: From the date of radical surgical resection to the first confirmed disease recurrence by imaging or pathology, or death from any cause, whichever occurs first. Disease recurrence, including local recurrence and distant metastasis, is assessed by imaging examinations (CT/MRI ± PET-CT) or confirmed by histopathological evidence. For patients without recurrence, follow-up data will be censored at the date of the last disease assessment.
• Overall Survival [up to approximately 24 months]: Time from the date of first study intervention to the date of death from any cause or the date of the last confirmed survival follow-up. Long-term survival will be tracked through regular follow-up visits until death, loss to follow-up, or study termination.
• Objective Response Rate [up to approximately 24 months]: Imageological evaluation was conducted according to the RECIST 1.1 criteria for solid tumors. Target lesions included both the primary pancreatic tumor in situ and measurable metastatic lesions in the liver or lungs. Quantitative measurement of the longest diameter of each target lesion was performed using contrast-enhanced CT or MRI, and the sum of the longest diameters was calculated to determine the change, thereby assessing tumor response.
• Incidence of Adverse Events [From the first study intervention until 30 days after the last treatment or up to 24 months]: The incidence, severity, and type of adverse events (AEs) and serious adverse events (SAEs) evaluated according to the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE v6.0), as well as changes in laboratory tests, vital signs, and physical examinations.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* 1\. Aged 18-75 years, regardless of gender;
* 2\. Histologically or cytologically confirmed pancreatic ductal adenocarcinoma;
* 3\. Metastatic pancreatic cancer assessed by MDT as initially unresectable, with metastases confined solely to the liver or lungs, and no metastases to other organs beyond the liver or lungs;
* 4\. Liver or lung metastases: number of lesions ≤ 3, and maximum diameter of each lesion ≤ 3 cm;
* 5\. No prior systemic therapy for pancreatic cancer;
* 6\. ECOG PS 0-1;
* 7\. Child-Pugh score ≤ 7;
* 8\. Voluntarily signed informed consent form.

Exclusion Criteria:

* 1\. Diffuse hepatic/pulmonary metastasis;
* 2\. Participation in another interventional clinical study treatment within 4 weeks;
* 3\. Diagnosis of any other malignant disease other than pancreatic cancer within 5 years prior to the first dose (excluding cured cutaneous basal cell carcinoma, cutaneous squamous cell carcinoma, and/or radically resected carcinoma in situ);
* 4\. History of solid organ or hematopoietic stem cell transplantation;
* 5\. Suffering from any disease requiring systemic treatment with corticosteroids (prednisone or equivalent at a daily dose >10 mg) or other immunosuppressive drugs within 14 days prior to enrollment;
* 6\. Previous or current diagnosis of brain metastases with symptoms not fully controlled (i.e., persistent or worsening symptoms, or requiring adjustment of symptomatic treatment to maintain symptom relief);
* 7\. Uncontrolled active infection;
* 8\. Renal dysfunction: serum creatinine >176.8 μmol/L or creatinine clearance <30 ml/min;
* 9\. Uncorrectable abnormal coagulation function: platelet count <50×10⁹/L, prothrombin time >18 s, prothrombin activity <40%, and uncorrectable;
* 10\. History of ruptured esophagogastric varices that have not been effectively treated by endoscopy, interventional therapy, or surgery;
* 11\. Patients with psychiatric disorders in the active phase;
* 12\. Pregnant or lactating women, or women of childbearing age who plan to become pregnant within 3 months after the end of study treatment;
* 13\. Expected survival <3 months;
* 14\. Any other factors that the investigator deems unsuitable for inclusion or that may affect the subject's participation in the study.