Hypofractionated radiotherapy (HypoRT) has been used to pursue an alternative treatment regimen for patients with non-small-cell lung cancer (NSCLC) who are not eligible for stereotactic ablative radiotherapy (SABR), surgery or concurrent chemoradiotherapy (CCRT) and has shown good local control and safety. We analyzed the feasibility of using volumetric-modulated arc radiotherapy (VMAT) with the simultaneous integrated boost (SIB) technique to achieve high local control with few treatment-related toxicities.
A total of 55 patients with stage I-IV NSCLC who were not candidates for SABR, surgery or CCRT were included in the present study. All patients received a prescribed dose of 60 to 66 Gy in 15 fractions. Local progression-free survival (LPFS), PFS, overall survival (OS), and toxicities were retrospectively analyzed.
Thirty-three patients (60.0%) had stage IV or recurrent disease in this study. The median follow-up time was 8 months (interquartile range: 5.0-16.3 months). The 1-year and 2-year OS rates were 84.3% and 69.9%, and the 1-year and 2-year LPFS rates were 91.0% and 63.0%. The median OS (mOS) and median LPFS (mLPFS) were not reached, and median PFS (mPFS) was 15 months. Twenty-eight (51.9%) patients had disease progression at the time of analysis. Of these, 7 (13.0%), 7 (13.0%) and 21 (38.9%) had local recurrence, locoregional failure and distant metastasis, respectively. All cases of local recurrence were found within the SIB region. Four patients had grade 2-3 pneumonitis, and 8 patients had grade 2-3 esophagitis. Patients with grade 2-3 esophagitis had significantly higher maximum dose and dose to 5 cm3 volume to esophagus than those with grade 0-1 esophagitis. No grade 4 or higher toxicity was observed.
The 60 to 66 Gy in 15 fractions RT regimen provides favorable local control and survival with well-tolerated toxicities. Hypofractionated VMAT+SIB is an alternative treatment option for patients with NSCLC who cannot tolerate standard definitive therapy.