4121 - You need to be very careful when treating with radiation.

https://www.torahrecordings.com/rebbe/igroskodesh/012/005/4121 There are many other treatments with good results that are not as dangerous. Every one of the Chasidim needs to regard themselves as emissaries of our holy Rebbe's and needs to spread their teachings, guidance, and customs throughout the surroundings, the city, and their country.