ASCO 2015

Risks of adjuvant whole brain radiation therapy outweigh benefits for patients with limited brain metastases

Dr Jan Buckner - Mayo Clinic, Rochester, USA

You were taking on an important question and that is what to do about brain metastases. Can you tell me what it was you were trying to do with this study you’ve just reported here?

We were trying to determine if adding whole brain radiation to stereotactic radiosurgery resulted in better functional outcomes or worse functional outcomes. In other words, is the treatment worse than the disease?

Now, in fact, however, whole brain irradiation does bring quite a marked reduction in recurrences, doesn’t it?

Whole brain radiation does reduce the number of radiographically visible tumours. The question was whether or not that is associated with better or worse cognitive outcomes and in fact whole brain radiation is associated with worse cognitive outcomes, even though the disease control is better.

Can you describe to me what you did in the study?

Patients with 1-3 brain metastases were randomised either to stereotactic radiosurgery alone or stereotactic radiation plus whole brain radiation. The primary endpoint was cognitive decline three months following treatment.

And what happened in fact in terms of your measures of cognitive decline?

Patients that had whole brain radiation in spite of having fewer brain metastases had worse cognitive function at three months and at six months compared with stereotactic radiation alone.

What about other quality of life measures?

There were several other quality of life measures that were patient provided. There was worse functional outcome and physical outcome for the patients that had whole brain radiation based on the patients’ report.

And was there an impact on survival between the two arms?

There was no difference in survival between the two arms.

So what is your clear clinical finding, the outcome of this study?

The clear clinical finding is that whole brain radiation in addition to stereotactic radiation results in worse cognitive function than with stereotactic radiation alone.

And your recommendations to doctors all over the world?

Our recommendation is that as initial treatment for patients with 1-3 metastases, patients should have stereotactic radiation and then patients should be observed carefully for recurrent disease.

What about when there is a symptomatic decline? Is there a role for whole brain irradiation then?

I would say this is the context of the overall patient care because they may well have other disease and may have a very short life expectancy. Then, to a certain extent, it becomes an existential problem of whether or not the patient wishes to risk cognitive decline with possible longer term survival. Or is it appropriate to say we have done what is appropriate under the circumstances? I think it’s a very individual decision.

Finally and briefly, what is the moral coming out of this story that you’ve reported quite clearly here at ASCO?

I think the moral of the story is regardless of the treatments we utilise, we need to assess functional status in addition to imaging status to know how patients really experience the disease.