Poster - Thurs Eve-02: 3 dimensional ultrasound-guided breast brachytherapy.

Breast cancer is one of Canada's leading causes of death, taking the lives of approximately 5000 people annually. Breast-conserving tumour excision, or lumpectomy followed by radiation therapy is becoming an increasingly common treatment method for smaller tumours. High dose rate (HDR) brachytherapy is a precise form of radiation delivery following surgery involving the delivery of radiation dose through an HDR afterloader attached to catheters inserted into the breast. Currently, a CT scan of the patient is taken to properly reconstruct the tumour and guide catheter insertion. We propose to use our three-dimensional ultrasound (3DUS) scanner as the primary treatment planning device, eliminating the need for a CT scan. This would greatly increase patient comfort along with saving time and money. We have designed and constructed a 3DUS scanner specifically to be used in breast brachytherapy. It attaches to a Kuske breast application kit already used in the clinic. Software to view 3DUS images produced by the device is already being used, and needle guidance software is currently being developed. Laboratory tests on agar phantoms are set to begin shortly to evaluate the precision of the device and perform brachytherapy catheter insertion simulations. When the results of these tests are satisfactory, a full brachytherapy procedure will be performed in Quebec City using the 3DUS scanner.

[Analysis of the development of the arch form after treatment using "ARCAD'Image" software]. / Analyse de l'évolution de la forme d'arcade après traitement par le logiciel "ARCAD'Image".

The dental arch post-therapeutic modification plays a significant role in relapse phenomenon. This article describes the design work of the dental arches used as a base for the study of modifications that have arisen during orthodontic treatment then during the retention stage using pre-formed arch wires. ARCAD'Image software tries to design the patients dental arches by submitting a linear regression mathematical design on some characteristic landmarks of a photograph of the buccal impression. The designed dental arch can then be considered as being the closest/nearest to the patients morphology. This model enables the practitioner to bend the arch wire and is used as a base for the study of arch shape modifications. Our study shows that the term "relapse" appears to be used excessively; it would be more matter of evolution due to changes in neuro-muscular balance along with facial aging.