AbstractID: 7459 Title: Design, development and performance of an adapter for
simulation of ocular melanoma patients in supine position for proton beam therapy
The design, development and performance of a patient assembly adapter system
for ocular melanoma patient simulation are presented. The aim for the construction of
the apparatus was to simulate the patients in the supine position using a commercial x-ray
simulator. The apparatus consists of a base plate, head immobilization holder and patient
assembly system that includes a fixation light and a collimator system.
The
reproducibility of the repeated fixation was initially tested with a head phantom.
Simulation and verification films with fixation light at (0,0) of seven consecutive patients
treated with proton beam therapy (PBT) were studied. Patients were positioned supine
during simulation using an individualized bite block and head mask immobilization
device and the patient adapter system. Two orthogonal x-rays were obtained for
obtaining the x, y, and z position of rings for EYEPLAN software. The verification films
were obtained in the treatment position having fixation light at (0,0). The results indicate
good agreement within uncertainties.
In conclusion, we may say that the results of this investigation showed that the
same planning accuracy could be achieved by performing simulation-using the adapter
described above in the supine position as obtained by simulating in a sitting treatment
position. The adapter can also be attached to the chair head for simulating in the seated
position using rotating arm x-ray unit. This will save radiation therapist time and will not
occupy the treatment room for simulation.