Impact of fraction size on lung radiation toxicity: hypofractionation may be beneficial in dose escalation of radiotherapy for lung cancers.

Purpose: To assess how fraction size impacts lung radiation toxicity and therapeutic ratio in treatment of lung cancers.

Methods And Materials: The relative damaged volume (RDV) of lung was used as the endpoint in the comparison of various fractionation schemes with the same normalized total dose (NTD) to the tumor. The RDV was computed from the biologically corrected lung dose-volume histogram (DVH), with an alpha/beta ratio of 3 and 10 for lung and tumor, respectively.