Everything I ever read about his death lists a diagnosis of lung cancer in November, removal of a large part of his lung, cobalt treatments and death in December. Most likely he would have lived longer if they hadn't been so aggressive with the cobalt treatments, as the early ones in the 1960's tended to be much less refined and pretty much gave a person severe radiation poisoning. Had a grandfather that had a similar fate where he got through the surgery to remove a tumor with little more than localized pain... but when they decided to do radiation treatments a month later he went down quick and was dead in about 2 weeks. Early days of cancer treatment were scary.