ESTRO 36 Abstract Book

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S609 ESTRO 36 2017
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contrast-enhancing regions. Inter-rater reliability was
evaluated by the intraclass correlation coefficient (ICC).
BTVs with a threshold of 1.6 and a union of these BTVs
with the consensus MRI-based GTVs were compared to the
consensus GTVs only. OTP-Masterplan® was used for
treatment planning. Dice coefficients and conformity
indices were used for comparing the consensus GTVs and
BTVs and for the union of consensus GTV plus BTV with the
original planning target volume (PTV).
Results
PET-MR imaging conducted prior to re-irradiation of 7
high-grade glioma patients (2 WHO grade III, 5 WHO grade
IV) was used for this planning study with three
independent raters. Median follow-up from initial
diagnosis was 52 months and median post-recurrence
survival 13 months. Median age at the beginning of re-
irradiation was 54 years and median KPS 80. Median post-
recurrence progression-free survival from the beginning of
re-irradiation was 8 months. Six patients received
bevacizumab concomitantly to re-irradiation and 1 patient
temozolomide. Median GTV volume ranged from 35 to 40.5
cc, median consensus GTV volume of all three raters was
41.8 cc, median BTV 36.6 cc and the union of consensus
GTV and BTV in median 59.3 cc. The ICC between the
raters was on average measures 0.96, 0.96 and 0.97. The
dice coefficient between the consensus GTV and the BTV
was in median 0.61 and the conformity index 0.44. The
dice coefficient between the union of consensus GTV and
BTV with a margin of 8 mm and the original PTV was
median 0.84 and the conformity index in median 0.73.
Conclusion
PET-MRI derived BTVs may help to adjust the margin at
treatment planning of recurrent high-grade glioma re-
irradiation and reduce inter-rater variability. The most
prominent advantage of this imaging modality is the „one-
stop-shop' including two coregistered imaging modalities
of high quality.
EP-1125 Concomitant temozolomide therapy improves
survival outcome of patients with multifocal
glioblastoma
M. Syed1, J. Liermann1, T. Sprave1, V. Verma2, J. Rieber1,
S.B. Harrabi1, N. Bougatf 3, D. Bernhardt1, A. Mohr 1, S.
Rieken 1, J. Debus1 , S. Adeberg1
1 Universitaetsklinik Heidelberg, Department of Radiation
Oncology, Heidelberg, Germany
2 University of Nebraska Medical Center, Department of
Radiation Oncology, Omaha, USA
3 University Hospital Heidelberg, Heidelberg Ion-Beam
Therapy Center HIT, Heidelberg, Germany
Purpose or Objective
Concomitant temozolomide (TMZ) therapy has been
established as first line treatment of malignant gliomas
after several studies had shown better survival outcomes.
These studies have largely been performed with patients
with unifocal lesions. Our study aims to investigate the
role of temozolomide therapy in multifocal glioblastoma
(GBM) along with radiotherapy by comparing differences
in survival rates of patients with unifocal GBM (uGBM) and
multifocal GBM (mGBM).
Material and Methods
We retrospectively analyzed 265 patients with primary
GBM undergoing radiation therapy at the Department of
Radiation Oncology, Heidelberg University Hospital
between 2004 and 2013. Of these, 202 (76%) were uGBMs
and 63 (24%) were mGBMs. 133 (65%) with uGBM and 43
(68%) with mGBM received concomitant treatment with
TMZ. First, progression-free survival (PFS) and overall
survival (OS) between groups were compared using the
Kaplan-Meier method. Second, univariate and multivariate
Cox proportional hazards regression was applied to discern
prognostic factors including TMZ with PFS and OS in the
cohorts.
Results
Hundred ninety-five patients (73%) experienced tumor
progression on follow-up MRI scans performed after
radiation therapy. Patients with mGBM experienced
significantly worse OS of 11.5 months (range 1.6 - 25
months) as compared to patients with uGBM with an OS of
14.8 months (range 1 – 55.9 months) (p=0.032), with
similar patient characteristics in both Groups. There were
no significant differences in PFS between the respective
groups (6.5 versus 6.6 months, p=0.750).
Concomitant TMZ therapy was associated with
significantly better OS in mGBM (8.3 vs 14.2 months, p =
0.006) and uGBM (11.7 vs 17.0 months, p<0.001).
Univariate and multivariate analyses for OS revealed a
negative prognostic effect for multifocal disease (p<0.001)
and a positive prognostic effect for concomitant TMZ
treatment in mGBM (p=0.008) and uGBM (p < 0.001).
Conclusion
Patients with mGBM generally experienced significantly
worse overall survival than patients with uGBM after
radiation therapy. Concomitant TMZ treatment improved
OS of patients with mGBM and uGBM by approximately five
months.
EP-1126 Whole brain radiotherapy of breast cancer
brain metastases: intracranial progression and
prognosis.
D. Ou1, L. Cao 1, C. Xu1, J. Chen1
1Ruijin Hospital- Shanghai Jiaotong University School of
Medicine, Radiation Oncology, Shanghai, China
Purpose or Objective
Despite the increasing systemic treatment for breast
cancer (BC), CNS metastases represent one of most
aggressive conditions of metastatic disease. The prognosis
became very diverse with regard to molecular subtypes of
the primary disease. The current study aims to assess the
survival benefit and pattern of intracranial progress of BC
patients with brain metastasis (BM) after whole-brain
radiotherapy (WBRT).
Material and Methods
A total of 79 consecutive BCBM, who were diagnosed and
treated with WBRT between Jan 2010 and Mar 2016 were
studied. All of them were diagnosed with primary invasive
ductal carcinoma. Molecular subtypes were defined in 77
patients, as following: Luminal A-like (n=14), Luminal B-
like (n=26), HER-2 positive non-luminal (n=13) and Triple
Negative (TN) (n=24).
Results
The median patient age at the diagnosis of BM was 49 years
(range 22–77 years) and the median KPS at BM was 80. The
median time to BM (TTBM) was 36 months (range 0-232
months). Sixty-five patients received upfront WBRT and 14
received WBRT subsequent to SBRT. Systemic treatment
were administered to 50 patients after WBRT, including
endocrine therapy in 10 patients, chemotherapy in 42
patients, anti-HER2 therapy in 14 patients.
The time to BM in patients with HER-2 positive was shorter
than Luminal-A like (20.5 vs. 89.0months，p <0.001).
Median overall survival (OS) after BM was significantly
associated with Breast-GPA 0-1, 1.5-2, 2.5-3 and 3.5-4
were 4.3, 14.0, 14.8 and18.2 months, respectively (p
=0.012, fig A). Univariate analysis found that KPS at the
diagnosis of BM, infra-tentorial metastases, total doses
and systemic therapy after WBRT were significantly
associated with OS after BM (p< 0.05). The multivariate
analysis showed infra-tentorial metastases, total doses
and systemic therapy after WBRT were independent
prognostic factors for OS after BM(p <0.05).
The median OS was significantly improved in HER-2 +
patients receiving anti-HER2 therapy after WBRT (25.4 vs.
5.6 months, p = 0.040). Also, the median OS was
significantly improved in GPA 1.0-2.0 patients who
received upfront WBRT (14 vs. 7.9 months, p = 0.012). The
proportion of occurrence of intracranial progress for