Novi TBI sistem/ Onkološki inštitut

TBI treatments was used at the Institute of Oncology Ljubljana with good clinical result. Due to the increasing unreliability of the system we currently use, we decided to design and manufacture a new system. New system proved to be reliable as the most im-portant parameter that was tested, speed of the treatment table,can be controlled within 0.2% of the prescribed treatment table speed. The system was manufactured in cooperation with the company PS d.o.o, Logatec, Slovenia.

We present only a short resume of TBI procedure. New system for translational method of TBI that was manufactured in cooperation with the company PS d.o.o. (PS d.o.o, Logatec, Slovenia). Basic components are: remotely controlled movable treatment couch with couch support system (rails), electronic cabinet and mobile control panel.A. Treatment couch and support system Rail guides of support system consists of three parts madeof aluminium, which are rigidly connected when system is in treatment position; all connecting elements are made of steel.The length of the assembled system is 504 cm and can be accomodated even in a small radiotherapy room (bunker). In our case the system is fixed diagonally on the floor in the bunker where we have 60Co treatment machine Theratron 780C. The driving system of the treatment table consists of precise tooth belt and servo motors with accurate regulation of table speed and position.

The cabinet is located in the treatment room and is connected to the mobile control panel in the operator’s room. With the control panel, we can control all important parameters among them actual speed and position of the treatment table.Among many tests of the system, the most important for our TBI technique is the one associated with the accuracy of the treatment table actual speed and its control. According to the system specifications, the data for actual speed are acquired every ms, and are averaged over 250 ms. The tests were carried out by monitoring the difference between prescribed and actual measured speed of the treatment table using mobile control panel.During the tests, we compared actual and prescribed speed of the treatment table. In none of the cases the difference between them was larger than 0.2%. This confirms that newly designed and manufactured system is reliable and ready for clinical use.