You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "when was radiotherapy first used to treat cancer?" whose answer is 1895.
Each document should contain about 30 words, and these documents should contain useful information.

Query: when was radiotherapy first used to treat cancer
Useful Output:

Doc 1: In the mid-20th century, both were engaged in research into the best possible radiotherapy technology for cancer treatment.
Doc 2: Emil Grubbe claimed to be the first person to attempt to treat cancer with X-rays, although the evidence on this is somewhat disputed. Meanwhile
Doc 3: In 1898, Maria Sklodowska-Curie and her husband Pierre Curie discovered the radium as a source of radiations. Only three years later, Becquerel
Doc 4: Since the first description of X-rays in 1895, radiotherapy has become a standard treatment option for a wide range of cancers around the world.
Doc 5: So, the use of radiation for medical purposes dates back to the late 1800s, when radiation was first discovered. However, it wasn't until the