Tuesday, July 1, 2008

Brachytherapy

Brachytherapy is an umbrella term used to describe three forms of radiation delivery: High Dose Rate, Low Dose Rate and Pulsed Dose Rate. These are all delivered via a machine frequently referred to as an "afterloader". So the terms brachytherapy and afterloader therapy are interchangeable.

The three deliver methods are simply variations in the strength and frequency of the dose. HDR (High Dose), LDR (Low Dose) and PDR (Pulsed Dose).







In brachytherapy, the patient and afterloader are placed into a lead shielded room. The afterloader contains a radiation source that is safely contained within an integral lead container. Tubes are connected between the patient and the afterloader to allow wires to feed the radiation source from the afterloader to the cancerous area in the patient. Brachytherapy is common in brain, prostate, cervical and many other types of other cancers.


The planning criteria for the room includes the following:
1. The room must be shielded to prevent radiation exposure to the adjacent areas. (Walls, floor and ceiling).

2. Both audio and video communication are used to maintain surveillance and communication between the patient and the technician. A CCTV camera and an intercom are used.

3. The afterloader is typically housed in a lead lined room in the oncology department or cancer center and transported to the patient.

Brachytherapy can occur in a lead-lined patient room or within a specialized room designed specifically for brachytherapy. If available, a linac vault can also be used. The ability to contain the radiation within the room, allow the staff to maintain visual and audio communication, and allow the transport of the afterloader from its "home" to the treatment space are the key design criteria.

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