ESTRO 36 Abstract Book

617 / 1082

S601 ESTRO 36 2017
_______________________________________________________________________________________________
associated with progression ( p=0.003). When stratified
into 3 groups according to the surgical resection status and
ART, the patients treated with STR alone showed
significantly lower PFS, while those treated with GTR and
STR plus ART did not (3-year PFS, 30.8% vs 91% vs 83.6%;
p=0.013).
Conclusion
Although the most important prognostic factor related to
progression was the surgical resection status, ART in
patients with STR improved PFS, which is similar to those
with GTR. Routine use of ART after STR is recommended.
EP-1106 Local control and overall survival after
frameless radiosurgery
A. Bilger1, F. Frenzel1 , O. Oehlke1, R. Wiehle1, D.
Milanovic1, V. Prokic2, C. Nieder3, A.L. Grosu1
1 University Medical Center Freiburg, Department of
Radiation Oncology, Freiburg, Germany
2 University of Applied Sciences Koblenz, Department of
Radiation Oncology and Medical Technology, Koblenz,
Germany
3 Institute of Clinical Medicine, Faculty of Health
Sciences- University of Tromsø, Tromsø, Norway
Purpose or Objective
Stereotactic radiosurgery (SRS) has been increasingly
advocated for 1-3 small brain metastases. Goal of this
study was to evaluate the clinical results in patients with
brain metastases treated with SRS using a thermoplastic
mask non-invasive fixation system and image-guided
treatment.
Material and Methods
In this single-institution study 48 patients with 77 brain
metastases were treated between February 2012 and
January 2014. The head fixation was realized using a
BrainLAB thermoplastic mask. The prescribed dose was 20
Gy or 18 Gy as a single dose. The SRS were performed with
a True Beam STX Novalis Radiosurgery LINAC (Varian
Medical Systems). The verification of positioning was done
using the BrainLAB ExacTrac ® X-ray 6D system and cone-
beam CT.
Results
In 69 of 77 (89.6%) treated brain metastases the follow-up
was documented on MR imaging performed every 3
months. In 7/69 (10.1%) brain metastases local failure was
diagnosed with a mean follow-up time of 10.7 months
(range 1-43 months). Estimated 1-year local control was
83.1%. Median progression free survival (PFS) was 3.7
months, largely due to distant brain relapse. Breast cancer
was significantly associated with a worse progression free
survival. A GTV of ≤ 2.0 cm³ was significantly associated
with a better PFS than a GTV > 2.0 cm³. We observed 2
cases of radiation necrosis diagnosed by histology after
surgical resection. No other cases of severe side effects
(CTACE≥3) were observed.
Conclusion
In our experience local control after frameless (ringless)
LINAC based SRS with mean follow-up of 10.7 months is
89.9%. Without the invasive head fixation radiotherapy is
more comfortable for the patients
.
EP-1107 Treatment Strategies for local and distant
recurrence after HFSRT of the Resection Cavity
A. Bilger1, E. Bretzinger1, H. Lorenz1, O. Oehlke 1, A.L.
Grosu1, S.E. Combs 2, H.M. Specht2
1 University Medical Center Freiburg, Department of
Radiation Oncology, Freiburg, Germany
2 Klinikum rechts der Isar- Technical University of
Munich, Department of Radiation Oncology, München,
Germany
Purpose or Objective
In patients undergoing surgical resection of brain
metastases the risk of local recurrence remains high (50-
60%). Adjuvant Whole Brain Radiation Therapy (WBRT)
can reduce the risk of local relapse but fails to improve
overall survival.
At the Departments of Radiation Oncology, University
Medical Center Freiburg and Department of Radiation
Oncology, Technical University Munich, a retrospective
multicenter study was performed to evaluate the role of
hypofractionated stereotactic radiotherapy (HFSRT) in
patients with brain metastases after surgical resection.
After a median follow up of 12.6 months (range 0.3 – 80.2
months) the crude rate for local control was 80.5%
(Manuscript in preparation). In this analysis we evaluated
the treatment strategies after intracranial local (LF) and
locoregional (LRF) failure.
Material and Methods
183 patients were treated with HFSRT of the surgical
cavity after resection of brain metastases. In addition to
the assessment of local control, distant intracranial
control, overall survival and progression-free survival
(manuscript in preparation), in this analysis we focused on
the evaluation of individual patient histories and
treatment strategies after intracranial recurrence.
Results
Imaging follow-up (cMRI) for the evaluation of LF and LRF
was available in 160/183 (87%) patients.100/183 (63%)
patients showed intracranial progression after HFSRT.
At the first time of recurrence 81/100 (81%) patients
received salvage therapy. Median time to the first
recurrence was 5 months (6LF, 73LRF, 21LF+LRF). 14/81
patients underwent another surgery, 78/81 patients
received radiation therapy as a salvage treatment (53%
WBRT). Patients with single or few metastases distant
from the initial site or WBRT in the past were re-treated
by HFSRT (14%) or stereotactic radiosurgery (SRS, 33%). In
case of second failure 32/48 patients received further
salvage therapy (10WBRT, 18SRS, 4HFSRT). Median time to
second recurrence was 10 months (5LF, 38LRF, 5 LF+LRF).
Twelve patients developed a third failure (2LF, 8LRF,
2LF+LRF) after a median time of 14 months and 6 of them
had a reirradiation (1WBRT, 4SRS, 1HFSRT). After a
median time of 23 months 5 patients had a fourth
recurrence (3LRF, 2LF+LRF) and 3 had another salvage
treatment (2WBRT, 1SRS).
Seven (3.8%) patients experienced radionecrosis. No other
severe side effects (CTCAE≥3) were observed.Conclusion
In our first analysis we have shown that postoperative
HFSRT to the resection cavity is a highly effective concept
leading to long-term local control after surgery (crude
rate for local control was 80.5%). In this analysis we
focused on salvage therapy in case of intracranial
progression. 100/183 patients developed intracranial
failure and 81 received a first salvage therapy. Thirty-two
of 48 patients with a second recurrence, 6/12 patients
with a third recurrence and 3/5 patients with a fourth
recurrence received salvage treatment without severe
side effects. Local failures are rare and distant
intracranial failures can be effectively salvaged by further
radiotherapy.
EP-1108 CyberKnife® stereotactic radiation therapy
for re-irradiation of recurrent high grade gliomas.
H. Grzbiela1, M. Stąpór-Fudzińska2, E. Nowicka 1, M.
Gawkowska1, R. Tarnawski1
1Maria Sklodowska-Curie Memorial Cancer Center and
Institute of Oncology, III Radiotherapy and
Chemotherapy Clinic, Gliwice, Poland
2Maria Sklodowska-Curie Memorial Cancer Center and
Institute of Oncology, Radiotherapy Planning
Department, Gliwice, Poland
Purpose or Objective
Patients suffering from brain tumors, especially high grade
gliomas (HGG), often have to face a recurrence of the
tumor, after the primary treatment. Stereotactic
radiotherapy with CyberKnife® seem to offer a valuable
treatment option.