. 2016 Aug 1;95(5):1367–1377. doi: 10.1016/j.ijrobp.2016.03.031

Table 1.

Summary of the radiation therapy planning and dose prescription process

Process steps
Tumor coverage aim
PTV	90% isodose to cover 98% of PTV
Tumor dose prescribed to the ICRU reference point initially selected to achieve
Lung	EQD_2mean 18.2 Gy
Prescribed tumor dose reduced by 10%, and further if needed to meet the following limits
Heart	D_100% <45 Gy, D_67% <53 Gy, D_33% <60 Gy
Spinal cord	D_0.1cc ≤ 47 Gy
Brachial plexus	D_30% ≤60 Gy, D_0.1cc ≤65 Gy
Esophagus	Dose to 1 cm³=65 Gy	Dose to 1 cm³=68 Gy	Dose to 1 cm³=71 Gy	Dose to 1 cm³ ≤63 Gy^∗
Limit for	Group 1: cohort 1	Group 1: cohort 2	Group 1: cohort 3	Group 2

Abbreviations: EQD_2mean = equivalent dose in 2-Gy fractions averaged across lung, excluding gross tumor volume (GTV); ICRU = International Commission on Radiation Units and Measurements; PTV = planning target volume.

Prescribed tumor dose finally limited to 63-73 Gy, patients being ineligible for the trial if this causes lung V_20Gy (the volume of lung excluding GTV receiving more than 20 Gy) or EQD2_mean to exceed 35% or 19.3 Gy, respectively.

^∗

This dose level increased to 65 Gy, and then 68 Gy as safety data became available from group 1.