The Kennedy brothers have spawned so many conspiracy theories that it seems excessive to add to the directory. But there's some speculation among medical professionals about Ted Kennedy's brain cancer diagnosis, which we're going to air. In particular: why was the recent operation to remove part of the senator's tumor conducted at Duke University Medical Center in North Carolina and not in Kennedy's home state?

Now Duke (in Durham, North Carolina) is ranked by US News and World Report among America's top ten cancer centers. Allan Friedman, the doctor who performed the surgery, is a "thought leader" in neuro-oncology, according to an official at the American Cancer Society. And wealthy patients facing a deadly disease do seek out the best treatment-even if that's only available out-of-state.

But Kennedy was first flown to Massachusetts General after he experienced seizures at the political dynasty's famous compound nearby at Hyannisport. Nearby Mass Gen is that match of Duke as a top-tier cancer treatment center. The local hospital would also be the default choice because it would have records of Kennedy's earlier health problems, such as the carotid artery blockage detected last year in the senator's neck. Yet that may also explain why the senator and his family decided to seek care elsewhere.

Mass Gen said Kennedy had shown no sign of a brain tumor when the arterial blockage was flagged by an MRI scan seven months ago. And the operation did indeed show that Kennedy's artery was 70% blocked, which would have given doctors reason to believe they had got to the root of Kennedy's problem.

But some of the symptoms of a malignant glioma, the deadly disease from which Kennedy suffers, can be confused for those of a blocked carotid artery, I'm told. And a fast-growing tumor might have been so small last year that it could easily be missed on a scan, according to Dr. Keith Black, director of neurosurgery at Cedars-Sinai.

Among some doctors unconnected with the case, there's an inevitable suspicion that Mass Gen missed the diagnosis and Kennedy switched to a hospital in which he had more faith.

One should not jump straight to that conclusion. Medical science is inexact. And Ted Kennedy and his family can't entirely have lost confidence in Mass Gen because the senator is receiving follow-up radiation and chemotherapy there.

But the fact remains that the tumor would have been much more amenable to treatment if it had been caught earlier. So here's a mission for some enterprising journalist at the Boston Globe or Boston Herald: find out what killed the last Kennedy brother.