Alana Thibodeau-Antonacci

Name: Alana Thibodeau-Antonacci

Level at MPU: MSc

Email: alana.thibodeau-antonacci [at]

Supervisor(s): Shirin Abbasi Nejad Enger

Research interests: Brachytherapy


Research summary

High dose rate brachytherapy is a form of radiotherapy where a radioactive source is temporarily placed via catheters inside the tumor using needles or in proximity to the tumor using special applicators inside a body cavity. This close contact with the area to be treated allows a very efficient dose delivery. However, radiation sources used in conventional brachytherapy provide rotationally-symmetric dose distributions, which deliver high doses to the tumor but often with poor target conformity due to the irregular shape of the lesion. This can result in dose spillage to the surrounding radiation sensitive organs, which increases the risk of negative side effects. By incorporating dynamically-rotating metallic shields, intensity modulated brachytherapy opens the possibility to deliver more conformal dose distributions by directing the radiation towards the tumor and away from organs at risk.

Worldwide, colorectal cancer is the third most commonly diagnosed cancer in men and the second in women. Up to a third of all colorectal cancer cases originate in the rectum with the majority being adenocarcinomas. Surgical resection is the primary curative treatment for this type of cancer, often preceded by neoadjuvant chemoradiotherapy. External beam radiation therapy is the best-studied form of radiotherapy in this context. This method delivers dose by aiming high energy x-rays or electrons from outside the body into the tumor. However, this type of treatment is associated with significant toxicities. Alternatively, preliminary results indicate fewer treatment related toxicities when high dose rate brachytherapy is used.

The goal of this project is to design and develop a dynamic-shielding intensity modulated brachytherapy applicator for the treatment of rectal cancer to reduce the dose received by the organs at risk while ensuring an optimal irradiation of the tumor. Different brachytherapy sources will be investigated and a novel Monte Carlo based treatment planning system will be used to find the best dose distribution for each patient.

A better shielding of organs at risk allows for dose escalation to the tumor, which can significantly improve the curative potential of this treatment, while simultaneously increasing the quality of life of patients.

Key publications

Mansour, R., A. Thibodeau Antonacci, L. Bilodeau, L. Vazquez Romaguera, M. Cerny, C. Huet, G. Gilbert, A. Tang and S. Kadoury (2020). "Impact of temporal resolution and motion correction for dynamic contrast enhanced MRI of the liver using an accelerated golden-angle radial sequence." Phys Med Biol 65(8): 085004

Thibodeau-Antonacci, A., L. Petitclerc, G. Gilbert, L. Bilodeau, D. Olivie, M. Cerny, H. Castel, S. Turcotte, C. Huet, P. Perreault, G. Soulez, M. Chagnon, S. Kadoury and A. Tang (2019). "Dynamic contrast-enhanced MRI to assess hepatocellular carcinoma response to Transarterial chemoembolization using LI-RADS criteria: A pilot study." Magn Reson Imaging 62: 78-86.


FRQNT MSc Scholarship (2020)

FRQS MSc Scholarship (2020) - Declined

McGill Graduate Excellence Fellowship (2019)

NSERC Alexander Graham Bell Canada Graduate Scholarship Master Award (2019)

ISMRM Trainee Educational Stipend (2018)

UdeM Excellence Scholarship (2015)


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