Hypofractionated Image-guided Radiation Therapy (3Gy/fraction) in Patients Affected by Inoperable Advanced-stage Non-small Cell Lung Cancer After Long-term Follow-up

Abstract

Background: We conducted long-term follow-up analysis of the outcomes for patients affected by advanced-stage non-small cell lung cancer (NSCLC) treated with hypofractionated radiotherapy (RT).

Materials and methods: Sixty patients with advanced-stage NSCLC (IIIA-IV) treated with hypofractionated radiotherapy (60Gy/20 fractions) were analyzed. Radiation was delivered using an image-guided RT technique to verify the correct position. Toxicities were graded according to the Common Toxicity Criteria for Adverse Effects v4.0 scale.

Results: Overall, six patients achieved a complete response and 46 patients had a partial response (tumor response rate 86%). After a median follow-up of 30 months, locoregional progression occurred in 23 patients and distant progression occurred in 38. The 1-year and 2-years overall survival were 57% and 40%, respectively. The 1-year and 2-years progression-free survival (PFS) were 47.1% and 33.5%, respectively. The median duration of OS and PFS was 13 months and 12 months, respectively. The 2-year local PFS and metastases-free survival (MFS) were 53% and 40.3%, respectively. On univariate analysis, the T-size (≥5 cm), and type of response to RT (non-response/progressive disease) were significantly associated with worse OS. Type of response was identified as significant prognostic factors for PFS (p<0.01) local PFS (p=0.015) and MFS (p<0.01). Acute grade 3 esophagitis and pneumonitis occurred in three patients (5%) and four patients (6%), respectively. Late grade 3 esophagitis and pneumonitis occurred in 2% (one patient) and 3% (two patients), respectively. No patient experienced grade 4 acute or late RT-related toxicities.

Conclusion: Hypofractionated RT offers good disease control for patients with advanced-stage NSCLC with acceptable toxicity rates. Phase III randomized trials are necessary to compare hypofractionated RT with conventional RT.

Keywords: Hypofractionated radiotherapy; advanced stage; image-guidance; non-small cell lung cancer; unresectable.