(Light-sheet fluorescence microscopy) In vitro generated cancer multicellular spheroid of 1 mm of diameter. The spheroid has been imaged using a light-sheet fluorescence microscope. In the last decade, it has been extensively established that cancer multicellular spheroids represent an efficient model to validate effects of drugs and radiotherapy treatments. However, a lack of methods for quantitative analysis today still limits the usage of spheroids as models for routine experiments. Accordingly, there is an important call on the topic for the computer vision community.