Naiyer Rizvi, MD: Tim, you know brain metastases are certainly very common in these patients. ALK-fusion patients especially tend to have a higher incidence of these brain metastases. Do you screen them often? Do you manage them with SRS [stereotactic radiosurgery] gamma knife? What’s your approach for the brain metastases in these targeted-therapy patients?

Tim Kruser, MD: There was some concern with the first generation and some earlier reports that the discordant responses warranted earlier brain-directed radiotherapy. We’ve become far more comfortable with osimertinib and erlotinib and such, doing surveillance. I often see these people at 1 month just to make sure they are responding, and then backing off to q3 [every 3 months] to q6 [every 6 months] MRI [magnetic resonance imaging] scans and hopefully instituting radiosurgery if they start to have localized progression. I would put a plug in as well for the recent hippocampal avoidance study that came out, which is making whole-brain radiation—although we are still loath to use it early—a more tolerable approach if we have to use it for diffuse progression at a later time.

Naiyer Rizvi, MD: For most of these patients, for whom the EGFR and ALK therapies have such good brain penetration, do you tend to just observe them initially?

Tim Kruser, MD: Yeah, the scenario that comes in is someone presents with symptomatic or larger, bulkier lesions, and you’re waiting for the targeted therapy. They’re a nonsmoker, and you’re not sure if you should institute radiation and wait and hope, so that can be a challenging clinical scenario. It’s not as challenging if it’s a radiosurgery option because you’re not as concerned about long-term toxicity. But if it’s burden of disease, that’s either whole-brain radiation or nothing. And you hope you can wait and use a targeted molecular therapy.

Transcript Edited for Clarity