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

International Journal of Cancer Therapy and Oncology

KR Muralidhar¹  A Poornima²  Adavala Mallikarjuna²  Birendra Kumar Rout²  P Narayana Murthy³ 

[1] Department of Radiation Physics, American Oncology Institute Nallagandla, Lingampally, Hyderabad, India;Department of Radiation Physics, Indo-American Cancer Institute, Hyderabad, India;Department of Radiation Physics, Nagarjuna University, Guntur, India;

关键词: IORT;    Intrabeam;    X-Ray Source;    Isotropy;    Photo Diode Array;   

DOI  :  10.14319/ijcto.0204.15

来源: DOAJ

【 摘 要 】

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 cm³ 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.

【 授权许可】

Unknown