ESTRO 36 Abstract Book

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S749 ESTRO 36
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who received five-fraction stereotactic body radiation
therapy (SBRT) at our institution.
Material and Methods
Patients presenting with biopsy-proven, solitary, small (<5
cm) extracranial metastasis from a gynecologic primary
cancer, treated with robotic SBRT, were retrospectively
reviewed. Vaginal cuff recurrences or multiple sites of
disease were considered exclusion criteria for this
analysis. Patients were stratified by the presence or
absence of sarcomatous histology. The Kaplan-Meier
method was used to estimate local control and overall
survival. Durable local control was defined as lasting ≥12
months. Toxicity was scored per the CTC-AE v4.0.
Results
Twenty patients were treated over a five year period from
July 2007 to July 2012 for solitary extracranial metastases
from gynecologic malignancies. Sixteen patients were
noted to have non-sarcomatous histology (six uterine and
ten ovarian primary tumors), while four tumors were
identified as sarcoma (all uterine primaries). No patients
with solitary cervical cancer metastases were identified.
Metastases involved the liver, lung, abdomen, spine,
pelvis, and extremity. Thirteen patients had fiducials
placed for tumor tracking; abdominal and spine
metastases were tracked with a fiducial-less spinal
tracking system. The median gross tumor volume (GTV)
was 42.5 cc (range: 5 - 273 cc). The median dose delivered
to the GTV was 35 Gy (range: 30 - 50 Gy) over 5 to 9 days
(median: 6 days). At a median follow-up of 56 months
(range: 6 - 108 months), the 5-year local control and
overall survival rates were 71.2% and 47.5% respectively.
However, when stratified by histology, the local control at
5 years was 93.7% in patients with classical histology
versus 25.0% in patients with metastatic gynecologic
sarcoma (p < 0.01) and only 50.0% of the sarcoma patients
experienced durable local control. No grade 3 or higher
toxicity was observed during or following treatment.
Conclusion
Five-fraction SBRT is a versatile, well-tolerated, and
highly effective treatment option for small extracranial
gynecologic metastases with an excellent 5-year local
control of 93.7% in patients with classical ovarian and
uterine primary tumors. However, patients with
metastatic uterine sarcoma may require a more aggressive
or alternative treatment approach.
EP-1402 Impact of SBRT on pain and local control for
bone metastases: a systematic review and meta-analysis
J.M. Van der Velden1, A.S. Gerlich1, E. Wong2, E. Chow2,
M. Intven1, N. Kasperts1, W.S.C. Eppinga1, E. Seravalli 1,
M. Van Vulpen1, H.M. Verkooijen1
1 UMC Utrecht, Department of Radiation Oncology,
Utrecht, The Netherlands
2 Sunnybrook Odette Cancer Center, Radiation Oncology,
Toronto, Canada
Purpose or Objective
Pain due to bone metastases is the most common cancer-
related pain syndrome. Besides analgesics, conventional
radiotherapy has been the cornerstone in the management
of bone metastases. However, control of pain after
conventional radiotherapy is modest, approximately 60%.
Advances in radiotherapy technique enable the delivery of
potentially ablative radiation doses, while respecting
healthy tissue constraints under the heading of
stereotactic body radiotherapy (SBRT). We conducted a
systematic review and meta-analysis to quantify pain
response and local control after SBRT for bone metastases.
Material and Methods
Following the Preferred Reporting Items for Systematic
reviews and Meta-Analyses (PRISMA) guideline, Embase,
PubMed and Cochrane Libraries were searched with the
(synonym) terms ‘bone metastases’ and ‘stereotactic body
radiotherapy’. Studies delivering SBRT in 1 – 6 fractions to
patients with or without previous radiotherapy or surgery
were included. Information from studies reported in more
than one publication was collated, and the most complete
or recent article was cited. Study variables, including pain
response and local control rates, were extracted from the
selected articles. Pain response was defined as a complete
or partial (i.e., at least 2 points decrease in pain score)
response. To qualify for inclusion in the meta-analysis,
outcomes had to be reported on an individual patient or
lesion level, follow up had to be recorded at least 45% of
the study population, and the size of the study population
had to be 10 or more. Pooled estimates using random-
effects models were calculated for pain response and local
control rates.
Results
After screening of 2619 unique articles, 54 articles (3359
patients) were included in the systematic review. Twenty-
six articles (1627 patients/lesions) were included in the
meta-analysis for pain response, and 36 articles (2875
lesions) in the meta-analysis for local control. After SBRT,
pain response rate ranged from 62% to 98% (see forest
plot), and local control rate ranged between 25% and 97%
(see forest plot). Excluding the study with the lowest local
control rate, which included patients with spinal lesions
from hepatocellular carcinoma, the local control rates
varied between 74% and 97%. Pooled pain response rate
was 80% (95% confidence interval [CI] 72% – 87%) with high
heterogeneity (I2 = 77%). Pooled local control rate was 87%
(95% CI 84% – 90%) with high heterogeneity (I2 = 76%).
Conclusion
SBRT for bone metastases results in high pain control and
high local control rates. This observation needs to be
further confirmed within large randomized controlled
trials.