COMMISSIONING OF MEDICAL LINEAR ACCELERATORS WITH MATCHED PARAMETERS (MATCHED LINACS)

Abstract

Introduction. The quality of treatment in radiation therapy is critically important for achieving positive outcomes. Unplanned treatment interruptions can extend the overall course of therapy and increase the risk of tumor recurrence, which is a problem observed across all forms of radiation therapy.

Methods. One of the main causes of interruptions is equipment being out of service temporarily. One possible solution is to transfer patients between two linear accelerators without the need for replanning in the event of equipment failure. Integrating multiple accelerators within a department enhances the efficiency and flexibility of treatment. This study focuses on analyzing the dosimetric characteristics of two linear accelerators using a water phantom and an anthropomorphic phantom with 1386 diode detectors for treatment plan verification.

Results.  The percentage depth doses, dose profiles and dose outputs were compared. Verification of dosimetric maps of the plans were performed using the criteria that 95 % of the dosimetric map points agreed within 3 % / 2 mm (dose/distance). It was shown that the average discrepancy in dosimetric parameters is less than 0.5 %, indicating high precision. The average plan agreement level between two linacs is 98,3 %.

Conclusions. The results confirm the high reliability and accuracy of treatment planning on both accelerators, ensuring optimal patient treatment.

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