ESTRO 36 Abstract Book

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S274 ESTRO 36 2017
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Purpose or Objective
To determine the maximum tolerated dose (MTD) of
fractionated extracranial stereotactic radiotherapy (ESRT)
to lymph nodal recurrences in different clinical settings.
Material and Methods
Patients enrolled in a phase I clinical trial entered the
analysis. Each enrolled subject was included in a different
study arm, according to nodal site and previous
treatment. Dose has been prescribed according to ICRU
62. A four no-coplanar beams class solution or a
volumetric technique (VMAT) have been applied in all
patients. The planning target volume (PTV) has been
defined as gross tumour volume (GTV) plus 5-15 mm.
According to different arms, patients received an ESRT
dose ranging from 20 Gy up to the maximum planned dose
of 50 Gy in 5 fractions. Dose-limiting toxicity (DLT) was
any grade > 3 acute toxicity or any grade > 2 late toxicity.
The MTD was exceeded if 2 of 6 or 4 of 12 patients in a
cohort experienced DLT.
Results
101 patients (M/F: 47/54; median age 67 years, range 43-
87years) with 128 nodal lesions were treated. were
treated. Of these, 48 (37.5%) were nodal recurrences in
neck or chest, 34 (26.5%) were in abdomen and 46 (35.9%)
were in pelvis. The primary tumour was most frequently
gynaecologic cancer (44%), followed by genito-urinary
cancer (22%), gastro-intestinal (13%), lung (13%) and other
(9%). The median ESRT delivered dose was 35 Gy (20-50)
in five fractions. With a median follow up of 19 months (4-
104), the overall response rate was 88% (CI95: 80-93.6;
Complete Response: 68%; Partial Response: 20%), with
only 5% of patients developing disease progression. No DLT
was recorded in this group of patients. Two- and 4-year
local control were 81% and 70.2%, respectively. Two- and
4-year metastases free survival were 43.5% and 30.9%,
respectively.
Conclusion
In quite varied setting of lymph nodal recurrences an ESRT
treatment in five fractions up to a dose of 50 Gy is safe
and well tolerated.
OC-0523 SBRT for oligo-metastatic liver disease–effect
of chemotherapy and histology on local tumor control
R. Klement1, M. Guckenberger2, H. Alheid3, M.
Allgaeuer4 , G. Becker5, O. Blanck6, J. Boda-Hegemann7,
T. Brunner8, M. Duma 9, S. Gerum 10, D. Habermehl 11, G.
Hildebrandt12, V. Lewitzki13 , C. Ostheimer14, A.
Papachristofilou15 , C. Petersen16, T. Schneider17, R.
Semrau18, S. Wachter 19, N. Andratschke2
1 Leopoldina Hospital Schweinfurt, Department of
Radiation Oncology, Schweinfurt, Germany
2 University Hospital Zürich, Department of Radiation
Oncology, Zurich, Switzerland
3 Strahlentherapie Bautzen, Department ofRadiation
Oncology, Bautzen, Germany
4 Krankenhaus Barmherzige Brüder, Department of
Radiation Oncology, Regensburg, Germany
5 RadioChirurgicum CyberKnife Südwest, Department of
Radiation Oncology, Goeppingen, Germany
6 Universitätsklinikum Schleswig-Holstein, Department of
Radiation Oncology, Kiel/Lübeck, Germany
7 University Hospital Mannheim /University of
Heidelberg, Department of Radiation Oncology,
Mannheim, Germany
8 University Hospital Freiburg, Department of Radiation
Oncology, Freiburg, Germany
9 Klinikum rechts der Isar- Technische Universität
München, Department of Radiation Oncology, Munich,
Germany
10 University of Munich – LMU Munich, Department of
Radiation Oncology, Munich, Germany
11 University Hospital Heidelberg, Department of
Radiation Oncology, Heidelberg, Germany
12 University Hospital Rostock, Department of Radiation
Oncology, Rostock, Germany
13University Hospital Würzburg, Department of Radiation
Oncology, Wuerzburg, Germany
14University Hospital Halle, Department of Radiation
Oncology, Halle, Germany
15University Hospital Basel, Department of Radiation
Oncology, Basel, Switzerland
16University Medical Center Hamburg-Eppendorf,
Department of Radiation Oncology, Hamburg, Germany
17Strahlenzentrum Hamburg, Department of Radiation
Oncology, Hamburg, Germany
18University Hospital of Cologne, Department of
Radiation Oncology, Cologne, Germany
19Klinikum Passau, Department of Radiation Oncology,
Passau, Germany
Purpose or Objective
Stereotactic body radiation therapy (SBRT) is applied in
the oligometastatic setting to treat liver metastases.
However, factors influencing tumor control probability
(TCP) other than radiation dose have not been thoroughly
investigated. Here we set out to investigate such factors
with a focus on the influence of histology and
chemotherapy prior to SBRT using a large multi-center
database from the German Society of Radiation Oncology.
Material and Methods
From 17 german and swiss radiotherapy centers, data on
all patients treated for liver metastases with SBRT since
its introduction in 1997 has been collected and entered
into a centralised database as an effort of the SBRT task
group of the DEGRO.
452 SBRT treatments in 363 patients were analysed after
retrieval of patient, tumor and treatment data from the
aforementioned multi-center database.
Histolgy was considered through random effects in semi-
parametric and parametric frailty models. Dose
prescriptions were parametrized by conversion to the
biologically effective dose at the isocenter (BEDmax) using
the LQ formalism.
Results
After adjusting for histology, BEDmax was the strongest
predictor of TCP. Larger PTV volumes, chemotherapy prior
to SBRT and non-advanced motion management
techniques predicted significantly lower TCP. For an
average metastasis, the model predicted a BED of 208±76
Gy10 necessary for 90% TCP at 2 years with no prior
chemotherapy, but 292±109 Gy10 when chemotherapy had
been given. Breast cancer metastases were significantly
more responsive to SBRT with 90% TCP at 2 years achieved
with BED max of 178±65 Gy10 or 94±55 Gy10 with and without
prior chemotherapy, respectively. There was a tendency
that colorectal metastases had an inferior TCP.
Conclusion
Besides dose, histology and pretreatment chemotherapy
were important factors influencing local TCP in this large
cohort of liver metastases. After adjusting for prior
chemotherapy, our data adds to the emerging evidence
that breast cancer metastases do respond better to
hypofractionated SBRT compared to other histologies.
OC-0524 Phase II trial on SBRT for Liver Metastases:
Long-term outcomes and prognostic factors of survival.
T. Comito1, C. Franzese1, E. Clerici1, A. Tozzi1, C. Iftode1,
P. Navarria1, G.R. D'Agostino1, D. Franceschini1, F. De
Rose1, A. Ascolese 1, L. Di Brina1, S. Tomatis1, M. Scorsetti1
1Istituto Clinico Humanitas, Radiotherapy and
Radiosurgey, Rozzano Milan, Italy
Purpose or Objective
Liver is a common site of metastases for several
cancers. In selected patients with oligometastatic disease
confined to liver, surgical resection improves overall
survival (OS). Approximately 70–90% of liver metastases,
however, are unresectable and a safe and effective
alternative therapeutic option is necessary for these
patients. The aim of this study was to evaluate long-term