Would you treat a patient with small cell lung cancer (limited to lung and mediastinum) but also with a malignant pleural effusion with upfront definitive thoracic chemoradiation?

I would treat such a case as EXTENSIVE DISEASE. That means chemotherapy with 4 cycles of Plat/Etop, and restage with PET. If the pleural disease has gone by imaging or/and pleural tap, I would add thoracic radiotherapy 30 gy/10 fractions and PCI 2.5 gy X ten. If the pleural space remains positive, I would not add local thoracic radiotherapy, but would deliver PCI 20Gy in 5 fx or 30 Gy in 10 fractions. I am fully aware of the Seto report from ASCO '15, and await a peer review update publication, and rely on the Slotman NEJM report until that time. The CREST trial of +/- TRT did not show a survival advantage at one year, and only a benefit at 2 years. A peristent pleural effusion would bode poorly for 2 year survival.

We would not treat like limited stage but this is subset of extensive stage if have nice response to chemo would add thoracic RT with PCI