1953, Philips TU 1 rotating X-ray machine.
The X-ray tube is a standard therapy tube, 250 kV/25mA. Rotational treatment can be programmed over multiple arcs with interruption in between. The angle of rotation, start and stop angles and the velocity can be set. The machine is equipped with isocentric light markers. The portal film holder is folded away by remote control when the film dose is reached, so that the radiation doesn't have to be interrupted. An ionisation chamber for monitoring the given dose is part of the diaphragm system.
An important application of this machine will be the treatment of oesophagus carcinomas. In 1957, Dr. N.C. HARDER reports on 27 April during a 'Leeuwenhoek day': "Summary of the oesophagus carcinomas treated with X-rays."
Siemens Convergence machine.
The conventional X-ray tube (220 kV) is fitted on a converging collimator, see photo..
The collimator is in contact with the patient in a steady position. During the irradiation, the X-ray tube moves in a spiralling motion from the middle to the edge of the collimator. As the tube gets closer to the edge of the collimator, it is tilted more so that the central axis of the beam stays focussed on a target deeper in the patient. The aim is to significantly reduce the skin dose. However, the machine was not often used by Lokkerbol.
Radiation therapist Lyda Wallach-Elte at the control panel of the convergence machine
Dose distribution of convergence radiation, aimed at 8.5 cm depth. The skin sparing is about 50%, the homogeneity in the target area seems poor.
Apart from the machines for rotational therapay, the department has a number of units for static therapy.
Philips stationary X-ray unit for so called deep therapy. The X-ray tube is rated at 250 kV, 25 mA.
Philips Contact treatment unit, fitted with an X-ray tube type "Chaoul" at 50 kV high voltage.
With a short focus to skin distance of 2 to 4 cm and low X-ray energy this unit is designed for the treatment of superficial tumours and sparing of deeper seated tissues.