Goes down smooth.

We all know limiting dose to central structures is critical during lung stereotactic radiation (SBRT). Why? Because educated guesses on normal tissue tolerance at such high doses told us so. This large retrospective series from Princess Margaret questions whether dose constraints for the esophagus are too conservative. Institutional preference was for  60 Gy / 8 for central tumors and 48 Gy / 4 for peripheral tumors <3 cm, but about 15% of patients received 54 Gy / 3 usually for peripheral tumors >3 cm. The esophagus was limited to Dmax 45 Gy and D10cc < 40 Gy in 8 fractions, Dmax 40 Gy and D10cc < 35 Gy in 4 fractions, and Dmax 27 Gy in 3 fractions. Overall, the rate of any esophageal toxicity was only 3% (mostly G1-2), and only half occurred in patients with central tumors. So why ruin these stellar stats? Because tumor coverage is often sacrificed to meet these strict constraints. TBL: Perhaps we should accept a little more dysphagia in hopes of a little less lethal tumor recurrence. | Yau, Int J Radiat Oncol Biol Phys 2018