Incorporating Treatment Time into Butterfly Optimization to Reduce Total Treatment Time for Vaginal Cylinder...

Area of Science:

• Medical Physics
• Oncology
• Computational Biology

Background:

• Patient comfort and safety in high dose rate (HDR) therapy necessitate minimizing irradiation times while preserving treatment quality.
• Optimizing dwell times in HDR vaginal cylinder brachytherapy is crucial for precise dose delivery and reduced treatment duration.

Purpose of the Study:

• To employ the butterfly optimization algorithm (BOA) for simultaneous optimization of dwell times in HDR vaginal cylinder therapy.
• To achieve precise dose conformity and reduce total treatment time in HDR vaginal brachytherapy.

Main Methods:

• Utilized the butterfly optimization algorithm (BOA), a population-based meta-heuristic algorithm, for dwell time optimization.
• Developed an objective function incorporating root-mean-squared dose error (RMSE) and weighted total treatment time.
• Retrospectively re-optimized eight clinical HDR vaginal cylinder treatment plans using BOA.

Main Results:

• BOA-optimized plans demonstrated reduced treatment times by 5.4% to 8.9% compared to adaptive volume optimization algorithm (AVOA) plans.
• Achieved smaller dose deviations from the prescription in BOA-optimized plans compared to original plans.
• Reported time savings ranging from 13.1 to 47.7 seconds (or 29.3 to 64.6 seconds with 5 CI activity).

Conclusions:

• Dose optimization using the BOA algorithm results in superior dose conformity in vaginal HDR treatment compared to AVOA.
• Integrating total treatment time into the optimization process effectively reduces delivery time with minimal impact on dose conformity.
• BOA offers a promising method for enhancing efficiency and precision in HDR vaginal brachytherapy.