Grant: Operating Grant

Breast cancer affects more than 20 000 women each year in Canada. The treatment recommended for the majority of patients with stage I and II breast cancer is conserving surgery followed by radiation therapy. The radiation therapy treatment is usually performed in 4 to 5 weeks with 5 days of treatment per week. Various studies and current ongoing randomized trials have investigated methods to accelerate treatment, in which the irradiation portion of the treatment would be no more than a single week. This has become possible with the use of advanced imaging devices in the design and delivery of the radiation therapy treatments. Of all the methods used to deliver an accelerated breast treatment, brachytherapy offers the greatest potential to deliver a high dose to the tumor while sparing normal tissues because it brings a source close or inside the area to be treated. In prostate brachytherapy, this potential has reached an enhanced state with the recent combination of real-time 3D imaging of the tissues and the catheter/needle positioning, and modern planning tools. However to reach that level, breast brachytherapy (BBT) requires the use of an efficient imaging system. This proposal combines the unique strengths of two laboratories in Canada to demonstrate that a 3DUS guidance system can be used with efficacy in BBT for real-time tumor visualization, 3D contouring and choosing the right number and position of catheter used during insertion. Therefore, 3DUS will be the central technology for a complete treatment system, bypassing the need for CT imaging (extra radiation), increasing the precision and decrease the procedure time for BBT delivery. We anticipate that the 3DUS system will show superiority in term of procedure time, reduced CT dose, dose distribution and reduced # of catheters used (related to cosmetic and side effects). If proven, the system will have a tremendous impact on BBT procedures worldwide.