I typically wouldn't, given limited data. CALGB 31102 (phase 1 trial) looked into this and found the maximal tolerated dose (MTD) to be at 60 Gy in 24 fractions (i.e., 2.5 Gy/fx). There's another phase 1 trial from Wisconsin which showed similar results (i.e., 2.5 Gy/fx). With these results in mind,...

There is an ASTRO clinical practice guideline recommending "moderate hypofractionation" (specifically 3000 cGy/10 fx @ 300 cGy/fx and 4200 cGy/15 fx @ 280 cGy/fx) WITH concurrent chemotherapy in patients with stage III NSCLC deemed "unsuitable for curative intent therapy" (with many appropriate cave...

55 Gy in 20 fractions of 2.75 Gy can be considered with reasonable evidence suggesting efficacy and safety for most patients. SOCCAR (Maguire et al., PMID 25304298) randomized 130 patients with inoperable stage III NSCLC to 55 Gy in 20 fractions over 4 weeks with either sequential or concurrent...

I do not routinely offer this as it is not currently SOC, and do all I can to do standard 30 fractions. However, I have done it a few times because of a few reasons, to name a few: Patient refusal/inability to come for 30 fractions (usually tied to point 2) Social issues that cannot be mitigated b...