The word 'isotron' has no specific synonym in English. Nonetheless, depending on the context, it may be possible to find alternative words with similar meaning or use. For instance, if the word describes a type of particle accelerator, other terms like cyclotron or linear accelerator may be used. If it refers to a type of isotope used in medical imaging, PET or SPECT radiopharmaceuticals could be employed instead. However, 'isotron' is a somewhat uncommon term, and the context would be necessary to determine the most suitable substitute. It's always essential to consider the context when using words and finding synonyms, to ensure that the meaning is clear and appropriate.