Drugmakers are betting that delivering radiation directly to tumors will become the next big cancer breakthrough. Bristol Myers Squibb, AstraZeneca, Eli Lilly and other pharmaceutical companies have spent some $10 billion on deals to acquire or work with radiopharmaceutical makers. They've snapped up smaller upstarts to get their hands on technology that, while in its infancy, could treat numerous cancers. Read more on how this technology works: | CNBC