Abstract
Purpose: The authors report comprehensive commissioning and quality assurance (QA) procedures for Intrabeam, Intra-Operative radiotherapy (IORT) unit. The Intrabeam system miniature X-ray source is a 50 kV and 40 µA unit. Methods: The authors’ tests include measurements of output, beam deflection, isotropy, kVp and mAs measurements, quality index, isodose, reproducibility, linearity, depth dose verification, and 3D dose distribution. IC ionization chamber and the UNIDOSE dosimeter were used for the output commissioning. Probe adjuster/ionization chamber holder (PAICH) was used to check the mechanical straightness of the probe. For radiation tests, NACP parallel plate chamber, Standard Imaging electrometer, 30 × 30 × 30 cm 3 IAEA water phantom, solid water slabs, EDR-2 Films with RIT software, and ionization based survey meters were used. Unfors Xi platinum edition kVp meter was used to measure the kVp and mAs. Results: In mechanical QA test, X-Beam position (-0.09 mm), Y-Beam position (0.01 mm), and radial position (0.11 mm) errors were within the tolerance level. Isotropy test with PDA, survey meter, ion chamber, and film measurements also produced results within the specifications. Output measurements with PAICH and external chamber measurements were matched. Beam quality, linearity, and reproducibility values were ascertained at 50KV and 40 µA and found to be within limits. Isodose, 3D dose distribution, transverse, and horizontal profiles showed the good isotropy of the source. Conclusion: The authors’ methodology provides comprehensive commissioning and calibration procedures for the Intrabeam system.
Highlights
Intrabeam system (Carl Zeiss Surgical GmbH, Oberkochen, Germany) is a mobile unit used for Intraoperative Radiotherapy (IORT), especially for localized tumor irradiation and for sharp fall of dose from the source
Since Intrabeam system installed at our center was the first of its kind in India, various quality assurance procedures and radiation safety issues were to be addressed at the time of commissioning both from regulatory as well as operational standpoints
We have summarized the simple quality assurance (QA) procedures to test the various parameters of the IORT unit (50 keV, 40 μA)
Summary
Intrabeam system (Carl Zeiss Surgical GmbH, Oberkochen, Germany) is a mobile unit used for Intraoperative Radiotherapy (IORT), especially for localized tumor irradiation and for sharp fall of dose from the source. The heart of this system is a miniature with high dose rate and low energy X-ray source (XRS) equipped with a 10 cm long (ø 3.2 mm) probe. The tip of the XRS probe is placed into a lesion or a tumor bed. It is a truly flexible system for IORT. In IORT facility, the quality assurance needs to be more stringent due to miniature x-ray source and its high dose rate.[1,2] Since Intrabeam system installed at our center was the first of its kind in India, various quality assurance procedures and radiation safety issues were to be addressed at the time of commissioning both from regulatory as well as operational standpoints
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
