Commissioning and quality assurances of the Intrabeam Intra-Operative radiotherapy unit

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.

Intraoperative radiation therapy with 50 kV x‐rays: A multi‐institutional review

“…The latter include comprehensive testing and quality assurance of all delivery equipment along with beam data acquisition and validation. 41 The commissioning process may be divided into two broad categories: mechanical and radiation checks. Mechanical tests include the integrity checks of cables, QA devices, treatment applicators, robotic x-ray stand (including stand balancing and precision positioning tests), and software related to QA tests.…”

“…The radiation protection survey is followed by IORT commissioning measurements. The latter include comprehensive testing and quality assurance of all delivery equipment along with beam data acquisition and validation 41 …”

“…Other radiation measurements include a check of the x‐ray beam positioning (dynamic offsets <0.1 mm from center), dose isotropy (<5%), beam flatness/symmetry (for flat and surface applicators), and dose linearity and reproducibility (<1%). All of these tests have been described in detail by Muralidhar 41 …”

“…The latter include comprehensive testing and quality assurance of all delivery equipment along with beam data acquisition and validation. 41 …”

Assessment of two hemispherical and hemispherical-conical miniature sources used in electronic brachytherapy using Monte Carlo Simulation

“…Through these developments, electronic brachytherapy system has emerged as one of the most rapidly disseminating medical devices in the world. However, the core component of these systems is still the miniature tube that allows the low energy x-ray to be produced at high dose rates ( 20 ). The x-ray spectrum produced by this tube has a continuous distribution (bremsstrahlung effect) with a line spectrum characteristic ( 21 ), and has an extensive use in medical physics ( 22 ).…”