Time to local failure and prognosis in lung cancer treated with stereotactic body radiotherapy
PO-1278
Abstract
Time to local failure and prognosis in lung cancer treated with stereotactic body radiotherapy
Authors: Yasushi Hamamoto1, Hiromitsu Kanzaki2, Kei Nagasaki3, Kenji Makita4
1National-Hospital Organization Shikoku-Cancer Center, Radiotherapy, Matsuyama-city, Japan; 2National-Hospital Organization, Shikoku-Cancer Center, Radiotherapy, Matsuyama-city, Japan; 3National-Hospital Organization Shikoku-Cancer Center, Radiotherpay, Matsuyama-city, Japan; 4National-Hospital Organization Shikoku-Cancer Center, Radiothreapy, Matsuyama-city, Japan
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Purpose or Objective
Local failure of primary lung cancer treated with stereotactic body
radiotherapy (SBRT) occurs even after 2-years or more. Differences in prognosis
after local failure between early local failure (ELF, recurred within 2-years
from SBRT) cases and delayed local failure (DLF, recurred after >2-years
from SBRT) cases were investigated.
Material and Methods
Consecutive stage I-IIA lung cancer treated with SBRT was retrospectively
reviewed. In SBRT, 48 Gy in four fractions at the isocenter was delivered to
the primary tumors in principle. Local failure was diagnosed by periodical follow-up
CT with or without FDG-PET/CT.
Results
Between 2006 and 2012, 173 lung cancer (stage I, 141; Stage IIA, 32) in
155 patients were treated with SBRT. Twenty-eight tumors recurred locally with or
without simultaneous regional and/or distant failure (ELF, 14; DLF, 14). Median
time to local failure was 13 months (range 4-23 months) for ELF and 43 months
(range 28-94 months) for DLF. Simultaneous regional and/or distant failure tended
to be more frequent in DLF compared to ELF (57% vs. 21%; X2-test, p = 0.0530). Prognosis
after local failure was significantly poor in DLF cases. Two-year overall
survival rates calculated from local failure was 60% for ELF cases and 15% for DLF
cases (log-rank test, p=0.0195).
Conclusion
Regarding early-stage lung cancer treated with SBRT, prognosis after local
failure was significantly poor in DLF cases compared to ELF cases. In DLF
cases, simultaneous regional and/or distant failure tended to be more frequent.