Content uploaded by James B Yu
Author content
All content in this area was uploaded by James B Yu on Dec 11, 2017
Content may be subject to copyright.
survival and freedom from distant relapse were calculated using the
Kaplan-Meier method.
Results: The 5-year local control rate was 98%. Control of disease in
the orbit was achieved in all but one patient who developed an out-
of-field recurrence after irradiation of a lacrimal tumor and was
salvaged successfully with further radiation therapy. The 5-year
regional control rate was 91% (3 patients failed in the contralateral orbit
and 1 patient failed in the ipsilateral parotid). Freedom from metastasis,
cause-specific survival, and overall survival rates at 5 years were 76%,
89%, and 76%, respectively. Acute toxicity was minimal. Eight patients
(18%) reported worsened vision following radiation therapy, and cata-
racts developed in eight patients. Cataracts developed in 6 of 28 pa-
tients treated without lens shielding (21%) and 2 of 16 patients (13%)
treated with lens shielding. No patient developed significant late
lacrimal toxicity.
Conclusion: Radiation therapy is a safe and effective local treatment in the
management of orbital lymphoma.
Author Disclosure: S. Kharod: None. M.P. Herman: None. C.G. Morris:
None. J. Lightsey: None. W.M. Mendenhall: None. N.P. Mendenhall:
None.
2154
Shifts in Stereotactic Radiosurgery Platform Utilization for Brain
Metastases in the United States
H.S.M. Park,
1
E.H. Wang,
1
C.E. Rutter,
1
C.D. Corso,
1
V.L. Chiang,
2
and J.B. Yu
1
;
1
Yale School of Medicine, New Haven, CT,
2
Yale University
School of Medicine, New Haven, CT
Purpose/Objective(s): Single-fraction stereotactic radiosurgery (SRS) is
a crucial component in the management of limited brain metastases from
non-small cell lung cancer (NSCLC). Intracranial SRS has traditionally
been delivered using Gamma Knife (GK), but linear accelerator (LINAC)-
based SRS has become an alternative approach. In the absence of defin-
itive prospective trials comparing the efficacy and toxicities of treatment
using the two techniques, non-clinical factors such as technology acces-
sibility, costs, and efficiency may play a larger role in determining which
radiosurgery system facilities may choose to install. This study aimed to
test the hypothesis that LINAC utilization has increased over time
compared to GK and that a variety of clinical and non-clinical factors may
be associated with the adoption of these radiosurgery systems.
Materials/Methods: The National Cancer Data Base was used to identify
patients >18 years old with non-small cell lung cancer who were treated
with single-fraction SRS to the brain in 2003-2011. Patients who received
“SRS not otherwise specified” or did not receive radiation therapy dose
within the range of 12-24 Gy were excluded in order to reduce the po-
tential for misclassification. The chi-square test, t-test, and multivariable
logistic regression analysis were used to compare potential demographic,
clinicopathologic, and healthcare system predictors of GK vs. LINAC SRS
utilization, when appropriate.
Results: We included 1,780 patients, among whom 1,371 (77.0%)
received GK SRS and 409 (23.0%) underwent LINAC SRS. Over time,
the proportion of patients undergoing LINAC SRS steadily increased
from 3.2% in 2003 to 30.8% in 2011 (p<0.001). LINAC SRS was
adopted more rapidly by community vs. academic facilities (overall
29.2% vs. 17.2%, p<0.001). On multivariable analysis, four independent
predictors of increased LINAC SRS utilization emerged, including year
of diagnosis in 2008-2011 vs. 2003-2007 (adjusted odds ratio (AOR)
2.04, 95% CI 1.52-2.73, p<0.001), community vs. academic facility type
(AOR 2.04, 95% CI 1.60-2.60, p<0.001), non-West geographic location
(AOR 4.50, 95% CI 2.87-7.09, p<0.001), and distance from cancer
reporting facility of <20 vs. 20 miles (AOR 1.57, 95% CI 1.21-2.04,
pZ0.001).
Conclusion: Gamma Knife remains the most commonly utilized single-
fraction SRS modality for NSCLC brain metastases in the U.S. However,
linear accelerator-based SRS has been rapidly disseminating in the past
decade, especially in the community setting. Wide geographic variation
persists in the distribution of GK and LINAC SRS cases. Further
comparative effectiveness research will be needed to evaluate the impact of
these shifts on SRS-related toxicities, local control, and survival as well as
treatment costs and efficiency.
Author Disclosure: H.S. Park: Employee; Yale-New Haven Hospital.
E.H. Wang: None. C.E. Rutter: Employee; Connecticut Children’s
Medical Center. C.D. Corso: None. V.L. Chiang: Employee; Urology
Specialists, P.C. J.B. Yu: Research Grant; 21st Century Oncology, PhRMA
Foundation.
2155
Spine Stereotactic Body Radiation Therapy Outcomes in Patients
With Concurrent Brain Metastases
H.S.M. Park,
1
R.J. Colaco,
2
M.S. Laurans,
3
V.L. Chiang,
4
J.B. Yu,
1
and Z.A. Husain
1
;
1
Yale School of Medicine, New Haven, CT,
2
Department
of Therapeutic Radiology, Yale School of Medicine, New Haven, CT,
3
Department of Neurosurgery, Yale School of Medicine, New Haven, CT,
4
Yale University School of Medicine, New Haven, CT
Purpose/Objective(s): Stereotactic body radiation therapy (SBRT) is an
emerging technique for maximizing tumor and pain control in selected
patients with spinal metastases. Outcomes for patients who have also been
treated for brain metastases have not been well-described previously. The
goal of this study was to test our hypothesis that overall survival (OS)
following spine SBRT is comparable for patients with or without con-
current brain metastases.
Materials/Methods: We reviewed records of all patients treated with
SBRT for a spine metastasis from a non-central nervous system neoplasm
at our institution from January 2008 to January 2014. Chi-square analyses
and t-tests were used to assess the association of concurrent brain metas-
tases with demographic and clinicopathologic covariates. OS was calcu-
lated from the time of the first course of spine SBRT to death or last
follow-up. The log-rank test and multivariable Cox proportional hazards
modeling were used to evaluate the impact of the concurrent brain me-
tastases on OS.
Results: 78 patients underwent a total of 86 courses of SBRT. Median
patient age was 60 years (range 38 to 84 years), 59% were female, and
26% had radioresistant histologies (renal cell carcinoma or melanoma). A
single fraction was used in 92% of treatments, with a median dose of 18
Gy (range 10-24 Gy). Overall pain response was 84% and 1-year local
control was 90%. With a median follow-up of 18 months, 1-year OS was
46%. A total of 19 patients (24%) had concurrent brain metastases, among
whom 18 received stereotactic radiosurgery and 9 were diagnosed syn-
chronously with their spine metastases. Patients with concurrent brain
metastases were more likely to have radioresistant histology than those
without brain metastases (45% vs. 17%, pZ0.018). OS was not signifi-
cantly different between patients with or without concurrent brain metas-
tases on univariable analysis (48% vs. 40% at 1 year, HR 1.57, 95% CI
0.84-2.95, pZ0.16) or on multivariable analysis (HR 1.60, 95% CI 0.84-
3.06, pZ0.15).
Conclusion: Patients with concurrent brain metastases do not appear to
have a statistically significant OS detriment, suggesting that concurrent
brain metastases should not necessarily be considered a contraindication
for spine SBRT. Nearly half of the patients with concurrent brain metas-
tases were diagnosed synchronously with their spine metastases, empha-
sizing the usefulness of obtaining a brain MRI for complete staging prior
to spine SBRT. Further follow-up will be necessary to validate our
findings.
Author Disclosure: H.S. Park: Employee; Yale-New Haven Hospital. R.J.
Colaco: None. M.S. Laurans: Employee; Yale-New Haven Hospital. V.L.
Chiang: Employee; Urology Specialists, P.C. J.B. Yu: Research Grant;
21st Century Oncology, PhRMA Foundation. Z.A. Husain: None.
2156
Clinical Outcome after Fractionated Radiation Therapy for Pituitary
Adenoma
R.A. Abu-Hijlih,
1
Y. Ismael,
2
H. Ghatasheh,
2
A. Fawzi,
3
A. Alsharbaji,
4
M. Elyan,
2
B. Al-Haj,
2
and A. Almousa
2
;
1
King Hussein Cancer Center,
International Journal of Radiation Oncology Biology PhysicsE62