Table 1.

Definitions and specified designations for target volumes of interest: instructions for participants.

Target volume	Definition	Specified designation
Gross tumor volume (GTV)	The primary tumor (GTV_P) and clinically positive lymph nodes (GTV_N) seen on the pretreatment PET scan (standardized uptake value; SUV > 3), diagnostic CT scan, and/or treatment planning CT (>1 cm short axis diameter) will comprise the GTV. The GTV will always be located in the apex of the ipsilateral lung in this particular study. This volume(s) may be disjointed.	GTV_P GTV_N
Internal target volume (if used)	The ITV includes the envelope that encompasses the tumor motion for a complete respiratory cycle.	ITV
Clinical target volume	The CTV is defined to be the GTV plus a 0.5 cm to 1 cm margin as appropriate to account for microscopic tumor extension. The ipsilateral paratracheal lymph nodes (levels 2 and 4) and supraclavicular fossa lymph nodes will be defined as comprising part of the CTV for this protocol. If an ITV approach is used then the ITV plus 0.5 cm to 1 cm is added to the ITV to form the CTV. Elective treatment of the entire mediastinum will not be done. If a uniform margin is used for CTV expansion, please specify CTV_xxMM, where xx = the margin expansion in millimeters, as structure name (e.g. CTV_05MM denotes a 5 mm expansion margin); if a non-uniform margin is used, please designate the volume CTV.	CTV
Planning target volume	The PTV margin should account for setup uncertainties and may be individualized. The PTV will comprise the CTV with a minimum 0.5 cm (if daily imaging correction will be used), or a minimum 1.0 cm if daily imaging will not be performed. If a uniform margin is used for PTV expansion, please specify PTV_xxMM, where xx = the margin expansion in millimeters, as structure name (e.g. PTV_05MM denotes a 5 mm expansion margin); if a non-uniform margin is used, please designate the volume PTV.	PTV_xxMM