Five-field IMRT class solutions and dosimetric planning guidelines for implementing accelerated partial breast...

Area of Science:

• Radiation Oncology
• Medical Physics

Background:

• Accelerated partial breast irradiation (APBI) is an evolving technique for early-stage breast cancer.
• Standardized planning guidelines are crucial for reproducible dosimetric outcomes in APBI.

Purpose of the Study:

• To develop comprehensive planning guidelines for reproducible dosimetric results in external beam APBI.
• To establish class solutions and dose constraints for target coverage, conformity, and normal tissue sparing.

Main Methods:

• Simulated conservative patient setup on a linear accelerator with measured gantry and couch clearances.
• Developed reproducible and conformal 5-field intensity-modulated radiation therapy (IMRT) plans for 40 patients.
• Assessed plans based on patient-specific anatomy, including laterality and seroma location.

Main Results:

• Presented clearance tables for permissible gantry and couch orientations.
• Provided beam arrangement class solutions for left- and right-sided APBI.
• Reported dosimetric recommendations for target coverage, conformity, and normal tissue constraints (lung, breast, heart, liver), which were stricter than existing multi-institutional trials.

Conclusions:

• Developed and evaluated a 5-field IMRT technique for APBI, yielding highly conformal and reproducible plans.
• Provided clear methodology for implementing external beam APBI planning and delivery.
• Established stringent dose recommendations for improved patient outcomes.