Would you consider SBRT for multiple bilateral lung primaries and/or a lung primary with metastases to multiple lobes?

This is a difficult situation. There is not a ton of information on SBRT for synchronous lung nodules. Ironically I'm on one of the articles (Owen et al. Radiation Oncology, 2015). We treated 60+ patients with multiple nodules but many of them were metachronus, which is a bit different situation. Since I get the job of seeing and managing them most times, my approach has been more of clinical judgement, rather than founded in quality data. In someone like what you are describing, I'd be very hesitant to do 50/5 to all 3-4 nodules. I've done 2 at a time when forced by the biology, but I can't think of a time I've done 3 and never done 4. Cases like this, I visit with surgery and ask if they can wedge 1 or 2 and I SBRT 1 or 2. I do think that...

I agree with Dr. @Dr. First Last's thoughtful response from 5 years ago. Our group has some institutional data in a manuscript currently under review on 60 patients treated to synchronous lung primaries with SBRT simultaneously. Based on this, I believe that treating 2 or occasionally even 3 simultaneously could be safe in highly selected patients.

While I sometimes treat up to 2 isocenters at a time, I try to limit myself to 1 isocenter at a time to minimize the amount of time the patient has to stay on the table. This is typically easy to do in the case of multiple synchronous primary adenocarcinomas, since the untreated ones often grow indolently and may not change much (or at all) in the 3-6 months after treating the first lesion (when ...

I generally agree with the provided discussions. There is very little data. In my experience, I will treat a number up to the dose constraints (usually lung) that I would use for a stage III NSCLC. Practically, this depends on the size of the lesions and their proximity to each other. Of course, I recommend systemic therapy after the SBRT is done.