The goal of this observational study is to learn about the efficacy and safety of the Volumetric Modulated Arc Therapy (VMAT) dose sculpting technique combined with different radiotherapy doses (local dose escalation vs. conventional dose) in patients with unresectable pancreatic cancer, with a focus on survival outcomes, tumor response, and toxic/adverse effects.

The main question it aims to answer is:Does the VMAT dose sculpting technique combined with local dose escalation radiotherapy (total dose 60-65Gy) improve overall survival (OS), progression-free survival (PFS), and tumor response rate while maintaining acceptable safety (i.e., manageable toxic/adverse effects) compared to conventional dose radiotherapy (total dose 45-50.4Gy) in patients with unresectable pancreatic cancer? Participants who have already received VMAT (as part of their regular medical care for unresectable pancreatic cancer) at Chifeng City Cancer Hospital from February 2018 to May 2026 will be divided into two groups based on the radiotherapy dose they received: the study group (local dose escalation, 60-65Gy) and the control group (conventional dose, 45-50.4Gy). All participants will undergo follow-up via phone calls, WeChat, and outpatient re-examinations to collect data on their survival status (OS, PFS), tumor response (assessed by RECIST 1.1 criteria), and toxic/adverse effects (assessed by RTOG for radiation injury and CTCAE 4.0 for chemotherapy-related reactions) until the completion of outcome evaluation.

Inclusion Criteria:

• Patients with locally advanced pancreatic cancer confirmed by pathological diagnosis or PET-CT.
• Patients who refuse surgery or are inoperable.
• No history of radiotherapy.
• Aged 18-76 years with a performance status score of 0-1.

Exclusion Criteria:

• Patients with other concurrent primary malignant tumors.
• Patients unable to tolerate radiotherapy.
• Patients who are unable or unwilling to cooperate with the study.
• Patients with severe dysfunction of vital organs such as liver and kidneys.

he study population consists of patients with locally advanced pancreatic cancer recruited from Chifeng Tumor Hospital between 2018 and 2026. Inclusion criteria include: pathological or PET-CT confirmed diagnosis, age 18-76 years, Eastern Cooperative Oncology Group (ECOG) performance status 0-1, and no prior radiotherapy. Exclusion criteria are: concurrent other malignant tumors, severe liver/kidney dysfunction, inability to tolerate treatment, and unwillingness to cooperate with the study. Demographic and clinical characteristics such as age, gender, and disease stage will be recorded.