2-Dimensional IMRT dose audit: An Indonesian multicenter study.

Area of Science:

• Medical Physics
• Radiation Oncology
• Radiotherapy Quality Assurance

Background:

• Intensity Modulated Radiation Therapy (IMRT) is a precise radiation delivery technique.
• Accurate multileaf collimator function is critical for IMRT dose distribution.
• Deviations between planned and delivered IMRT doses can occur.

Purpose of the Study:

• To conduct a multicenter planar dosimetry audit of Indonesian radiotherapy centers.
• To evaluate IMRT delivery accuracy using AAPM TG-119 phantom data.
• To assess compliance with established dosimetry action levels.

Main Methods:

• Utilized AAPM TG-119 structure sets for dosimetry audits.
• Employed gamma index analysis with 3%/3 mm and 3%/2 mm criteria.
• Performed multicenter planar dosimetry evaluations across Indonesian radiotherapy centers.

Main Results:

• Achieved 100% gamma index passing rates for the 3%/3 mm criteria in most evaluations.
• Observed a decrease in gamma index passing rates with the stricter 3%/2 mm criteria.
• Confirmed that most participating centers met the tolerance limits for dosimetry action levels.

Conclusions:

• The multicenter audit demonstrated generally acceptable IMRT dosimetry accuracy in Indonesia.
• Stricter evaluation criteria highlight areas for potential improvement in IMRT delivery.
• This study provides a foundation for future standardized multicenter IMRT audits.