A comparison of the treatment techniques for a typical case of lung cancer has been performed between 10 Swiss radiation oncology centers. The description and basic imaging data of a locally advanced non-metastatic lung cancer were sent to each institution and participants were asked to perform the treatment planning as for a routine case. The comparison shows that, in addition to a broad spectrum of treatment techniques, there was a significant variation in the major treatment parameters: definition of the target volume, prescription procedure, total dose to the tumor and dose per fraction. Although some reasons could be found to partially explain these differences, the lessons learned from this comparison are, first, that a standardization, in particular for dose prescription, is urgently needed, and, second, that a search for a better consensus in standard managements should be promoted in radiation oncology.