What dose constraints do you use for 60 Gy in 15-20 fraction lung treatments that are adjacent to the hilum?

The LUSTRE trial, which is a Canadian RCT comparing SABR (60/8, 48/4) vs. 60/15 provides some max point constraints to address this for 15#.

Swaminath, Clin Lung Cancer. 2017 Mar;18(2):250-254.

Spinal Canal 36 Gy

Esophagus 48 Gy

Brachial Plexus 50 Gy

Heart 66 Gy

Great Vessels 66 Gy

Trachea/PBT 66 Gy

Skin ...

For tumors abutting the esophagus and PTV including a portion of the esophagus, what is your recommended dose fractionation? Esophageal Dmax is 50.5 Gy in SUNSET for 15 fraction regimen, which is difficult to achieve in this scenario without compromising PTV coverage. Thank you for your insight.

Could someone post the PTV planning objectives on the LUSTRE protocol? Specifically with regards to heterogeneity within the PTV. Unfortunately, the trial protocol is paywalled and my institution doesn't subscribe to that journal.

Swaminath et al., PMID 27876603