Leakage reduction for the Siemens ModuLeaf
| Autor: | R. Alfredo Siochi |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Treatment field
Materials science Siemens High resolution Radiation Dosage Linear particle accelerator law.invention Optics law commissioning Radiology Nuclear Medicine and imaging Instrumentation Leakage (electronics) Radiation business.industry Radiotherapy Planning Computer-Assisted Particle accelerator Tail region Multileaf collimator Particle Accelerators Radiotherapy Conformal Technical Notes treatment planning system Nuclear medicine business MultiLeaf Collimator |
| Zdroj: | Journal of Applied Clinical Medical Physics |
| ISSN: | 1526-9914 |
| DOI: | 10.1120/jacmp.v10i2.2894 |
| Popis: | The ModuLeaf, an add‐on miniature multileaf collimator (MMLC) for the Siemens ONCOR linear accelerator, provides high resolution field shaping with a maximum interleaf leakage dose of 1.50% at 6 MV. However, beyond the maximum treatment field size, the distribution of leakage and scatter along the y‐axis is different from that of the x‐axis, with maximum leakage values of 1.53% and 0.39%, respectively. Such differences cannot be modeled in the Pinnacle treatment planning system. Also, within the 10 cm×12 cm treatment region, leakage from the crack between closed leaf ends was 3.76%. To resolve these issues, gaps in the ModuLeaf frame were filled with lead sheets, and the Siemens MLC was operated in MLC mode (rather than bank mode). As a result, a rectangle of 10.4 cm×11 cm was formed with the MLC leaves closed behind the Y jaws, whose opening was 10.4 cm. This significantly reduced the difference between the leakage patterns in the x and y directions, with maximum leakage doses of 0.43% outside the treatment region and 1.67% near the crack between abutting ModuLeaf leaves. The modification also reduced the mean square error between Pinnacle profiles and measured profiles in the tail region. PACS number: 87.56.jk |
| Databáze: | OpenAIRE |
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