A total of
39 consecutive patients (60 metastases) were treated with
SBRT between April 2003 and August 2006 and retrospectively
reviewed. In all, 23 of 60 tumors had no previous radiation
(unirradiated) and 37/60 tumors had previous irradiation (reirradiated).
Of 37 reirradiated tumors, 31 were treated for “salvage”
given image-based tumor progression. Local failure was
defined as progression by imaging and/or clinically.
Results
At last
follow-up, 19 patients were deceased. Median patient
survival time measured was 21 months (95% CI = 8–27 months),
and the 2-year survival probability was 45%. The
median total dose
prescribed was 24 Gy in three fractions prescribed to the
67% and 60% isodose for the unirradiated and reirradiated
cohorts, respectively. The median tumor follow-up for
the unirradiated and reirradiated group was 9 months (range,
1–26) and 7 months (range, 1-48) respectively. Eight of 60
tumors have progressed, and the 1- and 2-year
progression-free probability (PFP) was 85% and 69%,
respectively. For
the salvage group the 1 year PFP was 96%. There was
no significant difference in overall survival or PFP between
the salvage reirradiated vs. all other tumors treated (p =
0.08 and p = 0.31, respectively). In six of eight failures
the minimum distance from the tumor to the thecal sac was ≤1
mm. Of 60 tumors treated, 39 have ≥6 months follow-up and no
radiation-induced myelopathy or radiculopathy has occurred.
