What dose constraints do you use when treating ultra-central lung tumors with a hypofractionated/ultra-hypofractionated approach using 8-10 fractions?

Typically, ultra-central lung tumors mean that they abut/invade critical central structures such as the bronchial tree, tracheal, esophagus, major vessels, etc. For these critical structures, particularly for the esophagus, bronchial tree and tracheal, ablative dose could cause severe chronic toxici...

This is what we use when we treat central lesions - 70 Gy in 10 fractions.

Total Lung Mean dose ≤ 9 , V40 ≤ 7%
Trachea V40 ≤ 1 cc, Dmax ≤ 60 Gy
Bronchial Tree V50 ≤ 1cc, Dmax ≤ 60 Gy
Hilar Major Vessels V50 ≤ 1 cc, Dmax ≤ 75Gy
Other Chest Great Vessels V50 ≤ 1 cc, Dmax ≤ 75 Gy
Esophagus V40 ≤ 1 cc, Dmax ≤...

In Canada, we have had a lot of experience with 60 Gy in 15 fractions for early lung cancer, and with ultra central tumors, this is our centre's usual go-to fractionation, unless patients are enrolled on the currently ongoing SUNSET trial. The constraints for 60/15 are largely based on the completed...