Multi-Institutional Phase II Study on the Efficacy and Safety of Dynamic Tumor-Tracking, Moderately Hypofractionated...

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Organ motion management is crucial for delivering high radiation doses to pancreatic tumors.
• Limited studies exist on organ motion management for pancreatic cancer.
• Dynamic tumor tracking (DTT) with intensity-modulated radiotherapy (IMRT) is a potential solution.

Purpose of the Study:

• To evaluate the efficacy and safety of DTT-IMRT in patients with locally advanced pancreatic cancer (LAPC).

Main Methods:

• Patients with confirmed LAPC were treated with DTT-IMRT using a linac system with gimbal function.
• The prescribed dose was 48 Gy in 15 fractions.
• The primary endpoint was the 1-year rate of freedom from locoregional progression (FFLP).

Main Results:

• DTT-IMRT was successfully administered to 25 patients.
• Median respiratory motion was 9.8 mm, with a median tracking accuracy of 2.6 mm.
• The 1-year FFLP rate was 75.3%, meeting the primary endpoint. Grade 3 acute GI toxicity occurred in 8% of patients, with no grade 4 or 5 toxicities.

Conclusions:

• DTT moderately hypofractionated IMRT provides effective locoregional control for LAPC.
• The treatment was well-tolerated, with no significant increase in severe toxicity.
• This approach represents a promising strategy for managing pancreatic cancer with organ motion.