To treat a pituitary tumor with radiation, doctors may use a variety of techniques depending on the size and location of the tumor. Conventional radiation covers a wide area in and around the tumor and is usually given daily for several weeks.
In the show, Stannis Baratheon dies under the sword of Jamie Lannister, wielded by a woman to fulfill a promise to Catelyn Stark, to avenge the death of Renly Baratheon. You can state he died of internal complications.
To defeat Bill in the series finale, Stan loses his memory, but regains it after seeing Mabel's scrapbook. He has been going by the name Stanford Pines, the name of his twin brother, and his real name is Stanley. He is based on Alex Hirsch's grandfather Stan.