The High Dose Rate Brachytherapy Unit at The Cancer Centre, Bahamas

Brachytherapy 

Brachytherapy is a method of delivering radiation to a tumor by placing radioactive sources either directly into the tumor or very close to it. 

By having the radioactive source close to the tumor, the radiation does not have to travel through normal tissue before it reaches the tumor. 

Furthermore, because the dose rate drops off rapidly as the distance increases from the source, very high doses of radiation can be delivered to the tumor while keeping the dose to surrounding normal tissue at a minimum. 

Although the physical advantages of brachytherapy were known soon after the discovery of radioactivity, there still were many challenges that limited its clinical use. For example, it is difficult to treat a deep-seated tumor using brachytherapy. The physical size of the isotope, the placement of it, and radiation exposure to hospital personnel limited the application and the quality of brachytherapy treatment. 

Brachytherapy also produces a highly heterogeneous dose distribution because dose around the radioactive sources is much higher than a region just a few millimeters away. This complex dosimetry and lack of proper instruments to analyze it limited its application and slowed the progress of brachytherapy. Despite these limitations, excellent results using the treatment in various types of tumors have been well documented. 

Recent discoveries in science and technology have lead to significant breakthroughs in the application and delivery of brachytherapy. New imaging modalities and faster computers have significantly improved the quality of the treatment and widened the application of brachytherapy for cancer. Elegant ultrasound and/or CT/MR-guided implant procedures allow radiation oncologists to apply brachytherapy in the most difficult clinical scenarios These techniques enable the radiation oncologist to visualize the tumor while placing the radioactive isotope or after-loading catheter. 

Using these quite harmless image guide procedures has dramatically improved the quality of implants.