A group of Dutch radiotherapists and physicists in a demonstration room of Siemens in Erlangen (DE) in the early 1950's. It is not certain on which occasion this photo was taken. It may have been a joint trip following the ICR radiology congress in Copenhagen (1953)
The following participants have been identified in the picture: on the far left Dr. Mann (Netherlands Cancer Institute NKI); at the front in the centre, left Professor Bakker, in the middle with dark coat and tie: Dr. Klaas Breur (Rotterdam Radiotherapeutic Institute RRTI), to the right in front of him Professor Siedzes des Plantes (University of Amsterdam); 4th from the right Ir. Bram Somerwil (physicist RRTI); on the far right Dr. Henri Lokkerbol (NKI).
Earlier, in the fall of 1951 a large group of Dutch radiotherapists and physicists led by Professor C. J. Bakker set out on a study trip to England.They visited the Atomic Energy Research Establishment in Harwell and several laboratories in London. The group learnt about medical applications of radioactive isotopes and the state of the development of linear electron accelerators for megavoltage radiotherapy. Dr Lokkerbol then travelled to the Christie's Hospital in Manchester and gave a presentation about his new radium equipment and radiation techniques.
In 1953 dr. Lokkerbol attended a course on dynamic radiotherapy (moving beam therapy) by Siemens in Erlangen (DE). Before, in 1950 he instructed the workshop and physics laboratory of the NKI to modify an X-ray unit with a remote controlled collimator, a rotating chair and optical fluoroscopy viewing. See the time line item in 1950. The growing understanding of the advantages of dynamic therapy and image-guidance led to the development of sophisticated equipment, suitable for routine use in the clinic. Examples on the time line are the rotating X-ray unit in 1954, and the image-guided Cobalt unit in 1961.