In high dose rate brachytherapy (HDR – Brachytherapy), which is offered at the GOC, we place guided catheters into pre-located positions inside or very close to the tumor so that the radioactive source Ir192 can be administered to the patient. This procedure is always carried out under the guidance/navigation of an ultrasound or CT Scan.
Once the comprehensive dosimetric plan, which specifies exactly where the catheter needles must be placed and how long should they remain in the patient, the catheters are then connected to an applicator and attached to a computer controlled machine, known as an afterloader.
The afterloader sends small radiation sources down the applicator and catheters delivering highly conformal doses with steep dose gradients to tumors that are not surgically resectable, mainly because of the close proximity to critical organs. The radiation sources are then left in place for a predetermined period of time.
The computer is programmed to control very accurately where the radiation is delivered and how long it remains in the organ. This ensures that a very precise and accurate dose of radiation is delivered to the tumor.
This procedure is carried out in special units which are radioactive-protected, the patient is alone but is observed via camera by the doctor and a medical physicist.
Once radiation has been delivered, the catheters are removed, if only one session has been decided, or remain implanted if the patient is programmed to repeat the treatment shortly.