ESTRO 36 Abstract Book

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S222 ESTRO 36 2017
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Proffered Papers: Upper and Lower GI
OC-0424 SBRT for Primary Liver Cancer in Routine
Clinical Practice: A Patterns-of-Care and Outcome
Analysis
T. Brunner1, N. Andratschke2, S. Gerum3, N. Abbasi-
Senger 4, M. Duma 5, O. Blanck6, V. Lewitzki7, C.
Ostheimer 8, F. Momm9, S. Wachter10, H. Alheit11, M.
Guckenberger2, E. Gkika1
1 Universitatsklinik Freiburg, Department of Radiation
Oncology, Freiburg, Germany
2 University Hospital Zurich, Department of Radiation
Oncology, Zurich, Switzerland
3 Ludwig-Maximilians-University, Department of
Radiation Oncology, Munich, Germany
4 Friedrich-Schiller-University Jena, Department of
Radiation Oncology, Jena, Germany
5 TU Munich- Klinikum Rechts der Isar, Department of
Radiation Oncology, Munich, Germany
6 University Medical Center Schleswig-Holstein,
Department for Radiation Oncology-, Kiel, Germany
7 University Würzburg, Department of Radiation
Oncology, Würzburg, Germany
8 Martin Luther University Halle-Wittenberg, Department
of Radiation Oncology, Halle an der Saale, Germany
9 Offenburg Hospital, Department of Radiation Oncology-,
Offenburg, Germany
10 Klinikum Passau, Radiation Oncology, Passau, Germany
11 Strahlentherapie Bautzen, Radiation Oncology,
Bautzen, Germany
Purpose or Objective
SBRT is not mapped on the treatment algorithms for
primary liver tumors. We evaluated safety and efficacy of
SBRT for primary liver cancer in a patterns-of-care and
patterns-of-outcome analysis.
Material and Methods
The working group 'Stereotactic Radiotherapy” of the
German Society for Radiation Oncology performed a
retrospective multicenter analysis of SBRT for
hepatocellular and cholangiocellular carcinoma (HCC and
CCC). Eleven centers with experience in pulmonary SBRT
participated. SBRT for this indication was introduced in
1999 and data were entered into a centralized database.
The analysis comprised 206 lesions in 174 patients after
retrieval of patient, tumor and treatment data from the
aforementioned multi-center database. HCC and CCC
were analyzed separately and pooled. Available factors
were analysed for local control (LC), overall survival (OS)
and toxicity.
Results
The range of lesions per center was 1–100 with a median
of 13 patients per center. In 174 patients 206 lesions were
treated, 134 (65%) HCC and 72 CCC lesions. Karnofsky
Performance Status was 80-100 in 88% and 60-70 in 12%.
Child-Turcotte-Pugh stage in HCC was A, B and C in 62%,
29% and 6%. Largest tumor diameter was median 5 cm (SD
3.9) with 144 patients having a single target lesion, 26
with 2, 3 with 3 and 1 with 4 lesions. PTV volume was
median 127 cc (5 - 3553). Median BED10 prescribed to the
PTV margin was 72 Gy (range 36 - 180 Gy): SBRT was
delivered in a median of 5 fractions (3-17) to a median PTV
prescription dose of 45 Gy (30 - 68 Gy ). Median follow-up
of patients alive was 12 months. Local control was 89%,
87% and 83% at 12, 18 and 24 months with no significant
difference between HCC and CCC. Two-year LC was 81%
vs. 91% (p = .075) for doses < 72Gy BED vs ≥ 72 Gy BED,
respectively. Median OS was 16.7 months, 17.5 months
and 14.6 months for HCC vs CCC (p=n.s.). Gastroduodenitis
was grade 2 or 3 in 2% and 1%, respectively. Data on other
toxicity was only available in 41% and was ≥ grade 2 in 4%:
this was esophageal variceal bleeding grade 2 in 3 patients
and deteriorated liver function in 3 patients.
Conclusion
This is to our knowledge the largest series on SBRT in
primary liver cancer reported. Local control is good in this
cohort for both HCC and CCC with a moderate median BED,
and median overall survival is well in the range of other
series of SBRT in these entities. Prospective trials should
be conducted to further validate the role of SBRT in
primary liver tumors.
OC-0425 Clinical experience with stereotactic MR-
guided adaptive radiation therapy for pancreatic
tumors
A. Bruynzeel1, F. Lagerwaard1, O. Bohoudi1, S. Tetar1, N.
Haasbeek1, S.S. Oei1, B. Slotman1, M. Meijerink 2, S.
Senan1, M. Palacios1
1VU University Medical Center, Radiation Oncology,
Amsterdam, The Netherlands
2VU University Medical Center, Radiology, Amsterdam,
The Netherlands
Purpose or Objective
The duodenum is the primary dose-limiting organ when
performing SBRT for locally advanced pancreatic cancer
(LAPC). With technical and imaging advancements, the
incidence of grade ≥3 small bowel toxicity (bleeding,
perforation, strictures) has decreased to <10%, but
potential toxicity continues to be a cause of concern.
Stereotactic MR-guided adaptive radiation therapy
(SMART) is a promising innovation, enabling besides daily
plan adaptation, optimal and real-time normal tissue
sparing while delivering high biological doses. The SMART
approach was clinically implemented at our center in May
2016, using the MRIdian system (ViewRay). We report on
SMART delivery in the first nine pts.
Material and Methods
SMART for LAPC is delivered in 5 fractions of 8 Gy (BED10Gy
72 Gy), in two weeks on non-consecutive days, with
prophylactic prescription of dexamethasone and
ondansetron. Target (GTV) and organs-at-risk (OAR)
contouring is performed on a MR-scan acquired at the
MRIdian 0.35T during a 17 sec shallow inspiration breath-
hold (BH). The GTV-PTV margin is 3mm, and the final PTV
(PTVopt) is created after subtraction of OAR within the
initial PTV. A BH MR is repeated prior to each treatment
fraction, and setup performed by GTV alignment. After
contour deformation and adjusting OAR within 3 cm of the
PTV opt, the original plan is re-optimized using the same
number and direction of IMRT beams, to create a “plan of
the day”. Patient specific QA includes an independent
dose calculation step, followed by treatment delivered in
BH periods under continuous MR-guidance. Respiratory-
gating is performed using the GTV within the PTVopt,
implying a 3mm safety boundary. BH is facilitated using an
in-house developed video-feedback system, consisting of
a mirror in the MR-bore and a monitor mounted at the
head end of the MRIdian. Pts can observe in real-time the
projected GTV within the PTV opt on a sagittal tracking
image derived from the MRIdian console (Fig 1).