Implementation and Evaluation of Phantomless Intensity Modulated Radiotherapy Delivery Verification Using...

Area of Science:

• Medical Physics
• Radiotherapy
• Quality Assurance

Background:

• Dynamic Intensity-Modulated Radiation Therapy (IMRT) requires precise delivery verification.
• Traditional verification methods can be time-consuming and require external measurement devices.
• Automated software solutions are needed to improve efficiency and accuracy in IMRT QA.

Purpose of the Study:

• To implement and evaluate the DynaLog file-based FractionCHECKTM software for automated IMRT delivery verification.
• To assess the software's performance in analyzing treatment accuracy for various patient cases.
• To determine the pass/warn/fail rates and analyze errors in dynamic IMRT deliveries.

Main Methods:

• Analysis of DynaLog files from 40 dynamic IMRT cases across different treatment sites (head & neck, brain, cervix, esophagus).
• Validation of FractionCHECKTM software using standard DMLC QA test fields.
• Calculation of mean RMS error, 95th percentile leaf error, and gamma analysis (1%, 1mm criterion) for planned vs. delivered fluences.

Main Results:

• Analysis of 1134 fractions and 25,166 log files from 40 patients.
• Overall pass rate of 95.4% (23,906/25,166 files), with 4.1% warning (1022) and 0.9% failure (238).
• Mean RMS error of 0.34±0.08 mm and mean 95th percentile leaf error of 0.66 ± 0.18 mm, meeting established safety standards.

Conclusions:

• FractionCHECKTM software offers an efficient, automated method for verifying IMRT treatment deliveries.
• The tool can be rapidly implemented, minimizing delays in busy clinical settings.
• FractionCHECKTM is a powerful, simple tool for routine QA and treatment delivery assessment in IMRT.