Prognostic value of semiautomatic CT volumetry in patients with stage i non-small cell lung cancer treated with stereotactic body radiation therapy

Objective: The aim of this study was to examine the prognostic value of semiautomated 3-dimensional image analysis-based parameters from pretreatment computed tomography (CT) in patients with nonCsmall cell lung cancer treated with stereotactic body radiation therapy. Methods: We evaluated 91 patients. We defined 2 parameters: (1) VOL, extracted tumor volume with a threshold ≥-400 HU; and (2) ATN, the mean CT attenuation value. The maximum standardized uptake value (SUV_max) was recorded as 18F-fluorodeoxyglucose positron emission tomography/CT parameter. The prognostic values were assessed using the Kaplan-Meier and a Cox proportional hazards analysis. Results: Overall survival and progression-free survival were significantly worse in patients with larger VOL, higher ATN, and higher SUV_max. VOL was an independent indicator of overall survival, whereas ATN was an indicator of progression-free survival, lymph node recurrence, and distant metastasis. However, SUV_max was not an independent prognostic factor for either outcome. Conclusions: VOL and ATN from 3-dimensional image analysis of CT scans have prognostic values for nonCsmall cell lung cancer patients treated with stereotactic body radiation therapy.