Proton Therapy for Unresectable and Medically Inoperable Locally Advanced Pancreatic Cancer: Results From a...

Area of Science:

• Oncology
• Radiation Oncology
• Medical Physics

Background:

• Proton beam radiation therapy (PBT) offers potential advantages over photon-based techniques for improving the therapeutic ratio in radiation therapy (RT).
• Data on PBT for locally advanced pancreatic cancer (LAPC) have been limited, primarily to single-institutional experiences.
• Evaluating PBT's efficacy and safety in LAPC requires multi-institutional data.

Purpose of the Study:

• To examine the toxicity, survival, and disease control rates of patients with LAPC treated with PBT.
• To assess outcomes from a multi-institutional prospective registry study.
• To compare PBT with established photon-based RT techniques for LAPC.

Main Methods:

• A multi-institutional prospective registry study involving 19 patients with inoperable LAPC treated with PBT.
• Patients received a median dose of 54 Gy in 30 fractions, often with concurrent or prior chemotherapy.
• Toxicity was assessed using NCI CTCAE v4.0, and survival outcomes were analyzed using Kaplan-Meier methods.

Main Results:

• No patients experienced grade ≥3 acute or chronic treatment-related adverse events; 78.7% had grade 1-2 events.
• Median overall survival was 14.6 months, with 2-year freedom from locoregional recurrence at 81.7%.
• Locoregional recurrence-free survival, distant metastasis-free survival, and time to new progression were 11.0, 11.0, and 13.9 months, respectively.

Conclusions:

• Proton beam RT for LAPC demonstrates excellent tolerability and maintains disease control and survival rates comparable to dose-escalated photon-based RT.
• The findings align with the physical and dosimetric benefits of proton therapy.
• Larger clinical studies are warranted to confirm these benefits and explore dose-escalated PBT for LAPC.