Recent local control rates of stage I NSCLC treated with stereotactic body radiotherapy
PO-1337
Abstract
Recent local control rates of stage I NSCLC treated with stereotactic body radiotherapy
Authors: Yasushi Hamamoto1, Hiromitsu Kanzaki1, Kei Nagasaki1, Kenji Makita1
1National Hospital Organization Shikoku Cancer Center, Radiation Oncology, Matsuyama, Japan
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Purpose or Objective
Stereotactic body radiation therapy (SBRT) for non-small cell lung cancer (NSCLC) was started at our hospital in 2006. In the last 10 years, we have changed the dose prescription method (from isocenter prescription to D95 prescription) and the dose calculation algorithm (from pencil beam convolution without inhomogeneity correction algorithm to anisotropic analysis algorithm). We investigated the local control rate (LC) of stage I NSCLC treated with SBRT in 2017-2018, and compared to that in patients treated with SBRT in 2006-2012.
Material and Methods
In our hospital, 48 NSCLC tumors were received SBRT in 2017-2018 and 172 NSCLC tumors received SBRT in 2006-2012. The principle prescribed doses were 42 Gy in 4 fractions for D95 in 2017-2018, and 48 Gy in 4 fractions for isocenter in 2006-2012.
Results
The median follow-up was 43 months for the 2017-2018 cases and 31 months for the 2006-2012 cases. The LC was 93.2% at 2 years and 90.4% at 3 years in the 2017-2018 cases and 89.9% at 2 years and 87.9% at 3 years in the 2006-2012 cases. There were no statistically significant differences between LC of 2017-2018 cases and that of 2006-2012 cases (log-rank test, p=0.3768).
Conclusion
There was no significant difference in LC between recent cases and early cases in our hospital. From our results, there seemed to be little effect of dose prescription methods, calculation algorithm, and institutional skill in SBRT technique.