Portal imaging by a.orphous silicon (aSi) photodiode is currently the most a.plied technology for in-vivo dosimetry (IVD) of static a.d dynamic radiotherapy beams. The strategy, a.opted in this work to perform the IVD procedure by a.i EPID, is based on: in patient reconstruction of the isocenter dose a.d day to day comparison between 2D-portal images to verify the reproducibility of treatment delivery. About 20.000 tests have been carried out in this last 3 years in 8 radiotherapy centers using the SOFTDISO program. The IVD results show that: (i) the procedure can be implemented for linacs of different manufacturer, (ii) the IVD a.alysis can be obtained on a.computer screen, in quasi real time (about 2min a.ter the treatment delivery) a.d (iii) once the causes of the discrepancies were eliminated, a.l the global IVD tests for single patient were within the a.ceptance criteria defined by: ±5% for the isocenter dose, a.d P γ<1≥90% of the checked points for the 2D portal image γ-analysis. This work is the result of a.project supported by the Istituto Nazionale di Fisica Nucleare (INFN) a.d Università Cattolica del S.Cuore (UCSC).
|Rivista||NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION A, ACCELERATORS, SPECTROMETERS, DETECTORS AND ASSOCIATED EQUIPMENT|
|Stato di pubblicazione||Pubblicato - 2015|
- In-vivo dosimetry