What's the plural form of hadrontherapy? Here's the word you're looking for.
Answer
The noun hadrontherapy can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be hadrontherapy.
However, in more specific contexts, the plural form can also be hadrontherapies e.g. in reference to various types of hadrontherapies
or a collection of hadrontherapies.