David Santiago Ayala Alvarez

Name: David Santiago Ayala Alvarez

Most recent degree: MSc.

Level at MPU: PhD.

Email: david.ayalaalvarez [at] mail.mcgill.ca

Supervisor(s): Dr. Jan Seuntjens

Research interests: Electronic brachytherapy, intraoperative radiotherapy (IORT), kilovoltage dosimetry


Research summary

Miniature kV x-ray tubes for electronic brachytherapy are used in intraoperative radiotherapy (IORT) applications to improve the outcome of targeted populations of cancer patients. The implemented low-energy electronic method is found to be a convenient alternative to interstitial brachytherapy with radionuclides, reducing the inherent safety risks and shielding, yet with a higher dose rate. The INTRABEAM system is one of the most distributed examples of these sources, which is calibrated using the manufacturer’s own protocol. A comprehensive and feasible in the clinic dosimetry protocol for electronic brachytherapy is essential and is in active research. In this project, a brachytherapy dosimetry model based on a modified version of the TG-43 protocol for the INTRABEAM source will be developed. In addition, the absorbed dose to water will be determined with the Exradin A20 parallel plate ionization chamber, which presents improved characteristics over the PTW 34013 such as precisely defined dimensions and the inclusion of a guard ring. Monte Carlo models for both methods will be validated based on measurements in water. The validated methods will be used to calculate dose to patient tissues and to establish optimized combinations of INTRABEAM with EBRT, studying the radiobiological implications.


Key publications


Ayala Alvarez D S, Watson P G F, Popovic M, Heng V J, Evans M D C and Seuntjens J 2020 Monte Carlo calculation of the relative TG-43 dosimetry parameters for the INTRABEAM electronic brachytherapy source Phys. Med. Biol. 65 245041 https://doi.org/10.1088/1361-6560/abc6f1



FQRS - PhD Research Scholarship (2020-2024)

RI-MUHC Studentship (2020) - Declined

CREATE / Medical Physics Research Training Network Program (MPRTN) (2018)

McGill - Max Stern Recruitment Fellowship (2017)

McGill - Graduate Excellence Award (2017)

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