Medical dosimetrists are members of the Radiation Therapy Treatment Planning Team. Medical dosimetrists use CT data or other measurements to create treatment plans for people who need radiation therapy.
Dosimetrists work mostly behind the scenes, and patients usually meet them only during their CT scans or simulations.
When attending a CT, the dosimetrist positions the patient on the CT table in the same way he/she will be positioned for their daily treatments. The dosimetrist works with the CT technologist to assure that all the required anatomy is scanned and that the data obtained meets any special requests made by dosimetrists, physicians, or physicists for a particular case.
Once the scan is obtained, the data is transferred electronically to the radiation therapy treatment planning system. The patients' anatomy is outlined in the computer, and a virtual patient is "built." The virtual patient is the exact shape, size, and position of the person it represents.
The dosimetrists' work is done using this virtual patient. Beam angles, sizes, and energies can be viewed and tested using the treatment planning software. The treatment planning software allows us to visualize the virtual patient three-dimensionally, with the treatment fields applied.
Beam entrance and exit points can be seen. Anatomy in the beam path can be reviewed and critical structures can be protected from the radiation field. Once beam directions and properties are decided, different beam shaping devices can be tested to find the correct device to create dose distributions to meet the needs of an individual patient.
All of this work can be done without the patient having to be present; the virtual patient assumes the burden of being available for uncomfortable and time-consuming measurements.
Any organ that can be outlined can be represented, for example skin, lungs, spinal cord, and right eye are entered.