11-year workload and barrier analysis for a high-energy linear accelerator

Authors

  • Isabela Rodrigues Rigo Faculdade de Medicina FMUSP, Universidade de São Paulo https://orcid.org/0000-0002-2705-6093
  • Ana Paula Vollet Cunha Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo
  • Caroline Zeppellini dos Santos Emiliozzi Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo
  • Gisela Menegussi Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo

DOI:

https://doi.org/10.15392/bjrs.v9i2.1687

Keywords:

shielding, workload, IMRT, VMAT

Abstract

The formalism used for barriers calculations is based on a conservative estimation of workload, use factor, and occupancy factor. IMRT techniques (Intensity Modulated Radiation Therapy) and VMAT (Volumetric Modulated Arc Therapy) are known for being superior to conventional techniques, but costly from the shielding standpoint, as they increase the number of monitor units used to deliver the same dose to the patient, increasing the leakage radiation produced and, consequently, the thickness of the secondary barriers. At InRad (Radiology Institute of HC-FMUSP) a 2100CD LINAC already installed was upgraded to perform IMRT/VMAT techniques, and the existing barrier was reassessed. The present study proposes a methodology for acquiring real workload data from the institution's management software (MOSAIQ®) to replace the initially estimated data and recalculate the thickness of the barriers, assessing the impact of the introduction of these techniques and understanding the profile of the treatments carried out at the institution over the years of 2010 to 2020. Through this methodology, a decrease in the workload of 15 MV was observed as the technique of modulated intensity with 6 MV was introduced, reducing the thicknesses calculated for primary barriers. However, no significant changes were observed in the thicknesses calculated for the secondary barriers, because despite the increase in the leakage workload of 6 MV, the total workload of 15 MV decreased. There was also a trend towards an increase in the number of patients treated with modulated intensity year after year, which went from 5% in 2016 to 67% in 2020.

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Author Biographies

Isabela Rodrigues Rigo, Faculdade de Medicina FMUSP, Universidade de São Paulo

medical physicist

Ana Paula Vollet Cunha, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo

Departamento de Radiologia e Oncologia, medical physicist

Caroline Zeppellini dos Santos Emiliozzi, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo

Departamento de Radiologia e Oncologia, medical physicist

Gisela Menegussi, Hospital das Clínicas HCFMUSP, Faculdade de Medicina, Universidade de São Paulo

Departamento de Radiologia e Oncologia, medical physicist

References

Steidley KD. NCRP Report No. 49: Structural Shielding Design And Evaluation For Medical Use Of X-Rays And Gamma Rays Of Energies Up To 10 MeV. Journal of Nuclear Medicine Technology. 1977 Jun 1;5(2):107-.

Schauer DA. NCRP Releases Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X-and Gamma-Ray Radiotherapy Facilities.

Rodgers JE. Radiation therapy vault shielding calculational methods when IMRT and TBI procedures contribute. Journal of applied clinical medical physics. 2001 Jun;2(3):157-64.

Mechalakos JG, Germain JS, Burman CM. Results of a one year survey of output for linear accelerators using IMRT and non-IMRT techniques. Journal of Applied Clinical Medical Physics. 2004;5(1):64–72.

Mutic S, Low DA, Klein EE, Dempsey JF, Purdy JA. Room shielding for intensity-modulated radiation therapy treatment facilities. International Journal of Radiation Oncology Biology Physics.1o de maio de 2001;50(1):239–46.

Price RA, Chibani O, Ma C-M. Shielding evaluation for IMRT implementation in an existing accelerator vault. Journal of Applied Clinical Medical Physics. 2003;4(3):231–8.

Reis Junior, J. P., V. G. L. Alves, and L. R. Fairbanks. Total Workload for Radiotherapy Facilities with Volumetric Modulated Arc Treatment. Brazilian Journal of Radiation Sciences. 2019; 7(3): 1-13.

Norma, CNEN. NE-3.01: Diretrizes Básicas de Proteção Radiológica.

Ali, Arif N., et al. "Dosimetric comparison of volumetric modulated arc therapy and intensity-modulated radiation therapy for pancreatic malignancies." Medical Dosimetry 37.3 (2012): 271-275.

Lafond, C., et al. "Quelle RCMI? Du «step and shoot» au VMAT: point de vue du physicien." Cancer/Radiothérapie 14.6-7 (2010): 539-549.

Van Benthuysen, Liam, Lee Hales, and Matthew B. Podgorsak. "Volumetric modulated arc therapy vs. IMRT for the treatment of distal esophageal cancer." Medical Dosimetry 36.4 (2011): 404-409.

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Published

2021-06-25

How to Cite

Rigo, I. R., Cunha, A. P. V., Emiliozzi, C. Z. dos S., & Menegussi, G. (2021). 11-year workload and barrier analysis for a high-energy linear accelerator. Brazilian Journal of Radiation Sciences, 9(2). https://doi.org/10.15392/bjrs.v9i2.1687

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