1950, a similar set up of an X-ray tube, motorized collimator, rotating chair and fluoroscopy screen was designed and constructed in the workshop of the Netherlands Cancer Institute (NKI).
This is the first description of a system for image-guided rotational therapy that has been found in the NKI archives. NB. The photo has most probably been provided to Lokkerbol by Siemens.
Lokkerbol studied rotational and multiple beam irradiation and presented his findings at the Leeuwenhoek study day in 1950. He made good use of the possibilities offered by the new physics and technical workshops, which were now under the direction of Mr. Sangster. One of his assignments was to develop a system allowing a rotational irradiation with a static X-ray machine of a patient sitting on a rotating chair. The idea came from a course on rotational irradiation, which had been given by Siemens in Erlangen.
The system consists of an X-ray collimator with a remote control for the collimator leaves, a rotating chair for the rotational irradiation and a screen for X-ray fluoroscopy. During the actual X-ray treatment the radiation beam is partly absorbed in the patient and the remaining, filtered beam makes the treated anatomy of the patient visible on the fluorescent screen. This image is observed by the radiologist via a mirror. If the irradiation deviates from the target area during the rotation, the field size and position can be corrected using remote control of the motorized collimator blades.