The New York Times has an excellent investigative report into radiation treatment errors. They tell the story of two patients who died due to errors, and report on the frequency of these events. Sadly the errors usually look preventable in hindsight. And predictably, manufacturers of the machines blame the technicians who operate the machines, when in truth a main cause is bad software design without proper attention to safety and usability practices.
The article is the first in a series called The Radiation Boom. This kind of deep reporting is what makes the NYT and organizations like it so valuable.