ESTRO 36 Abstract Book

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S669 ESTRO 36 2017
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In this investigation on patients treated for upper GI
cancer, we recommend that V35.6 Liver (relative) should
be held to < 22% in order to get upper GI toxicity grade ≥2
probability below 15%. Further investigations should be
done in order to observe significant dosimetric evaluation
in patients with grade≥3 toxicity.
EP-1255 Early clinical results for esophageal
brachytherapy using a novel multi-balloon HDR
applicator
A.S. Taggar1, G.N. Cohen1, P.J. Brady1, J.J. Cuaron1, A.
Wu1
1 Memorial Sloan Kettering Cancer Center, Radiation
Oncology, New York, USA
Purpose or Objective
Management of superficial primary and locally recurrent
esophageal cancer (EC) in medically inoperable patients is
complex. Endoluminal high-dose-rate (HDR)
brachytherapy (BT) has shown mixed results in terms of
toxicity and local control (LC). In this study, we assessed
the outcomes and toxicities in a set of patients treated in
a consistent fashion with a novel multi-balloon HDR
applicator (E-app) using CT-based planning.
Material and Methods
Five patients were treated with the E-app between
November 2015 and August 2016 in a single institution.
Their records were reviewed retrospectively under
institutional ethics board approval. All patients were
treated with HDR brachytherapy using the E-app and 3D
CT-based treatment planning, and received a total of 15
Gy in 3 weekly fractions prescribed to tumor volume. All
treatments were completed as planned. Four patients had
distal esophagus/GE junction tumors, and one patient had
mid-thoracic tumor. For one patient who presented with
squamous cell (SC) and another with and neuro-endocrine
(NE) histology, BT was the primary treatment. Three
patients had adenocarcinoma histology and were
previously treated with primary chemo/radiotherapy
(CRT); two had residual disease after primary CRT and one
presented with recurrence 8 years after initial treatment
with CRT. Two patients with residual disease received
concurrent Capecitabine, whereas all others were treated
with BT only.
Results
Patients’ median (range) age and KPS at the time of BT
were 76.6 years (66.0–87.6) and 80 (40–90), respectively.
Median length of treatment was 7.0 cm (5.5–9.0 cm).
Median dose to the hottest 0.3cc within defined
esophageal target volume (D 0.3cc) was 34.5 Gy (31.8–36.6
Gy). D 0.3cc and V100 of esophagus outside target volume
were 14.7 Gy (9.1–21.9 Gy) and 0.8 cc (0.0–3.6 cc),
respectively. Median follow-up from BT was 6.1 months
(1.7–7.3 months). Observed toxicities included dysphagia
(2 patients, grade 1 and grade 2), esophagitis (1 patient,
grade 1) stenosis (1 patient, grade 1) and asymptomatic
necrosis within the target area (1 patient, prior treatment
with 50.4 Gy + FOLFOX chemotherapy); no grade 3 toxicity
was observed. Repeat biopsy at 3 months’ post BT was
done in 3 out of 5 patients: 2 (patients with SC and NE
histology) had no evidence of disease and one had
persistent disease. One patient developed metastatic
disease and died without endoscopic assessment or biopsy
after BT.
Conclusion
This is the first report of clinical outcomes using a novel
multi-balloon HDR brachytherapy applicator (E-App). The
E-App appears to provide a safe and effective method of
delivering high doses of radiation to localized esophageal
cancers. We observed low rate of toxicity with short
follow-up and promising clinical and pathological
responses in the settings of recurrent and residual
disease.
EP-1256 Local ablative radiotherapy for liver
metastasis: factors affecting local control and survival
C. Petersen1, T. Gauer 1, T. Frenzel1, M. Todorovic1, A.
Krüll1, M. Blaschczyk1
1University Medical Center Hamburg - Eppendorf UKE,
Department of Radiation Oncology, Hamburg, Germany
Purpose or Objective
The liver is a common site of metastases from most
common solid malignancies. Currently available systemic
treatment regimens, result in transient to long-term
disease control, raising the question of further local
management. Secondary resection and thermo-ablation
may contribute to long-term survival or allow at least a
relevant chemotherapy-free interval. These approaches
are often limited. With stereotactic body radiotherapy
metastases can be treated with high efficiency in only a
few sessions. Here we evaluate the feasibility of high-dose
stereotactic body radiation therapy for liver metastases in
patients not eligible for surgery focussing on colorectal
cancer patients.
Material and Methods
Between July 2012 and December 2015, 33 patients with
56 liver metastases (range 1-4) were treated with SBRT.
Primary tumor mostly consists of colorectal cancer (59%)
and others (lung-, breast-, pancreatic cancer). Median
time between diagnosis of liver metastases and SBRT was
11 months (range 0-57 months). To receive precise
information about target localization, 3 gold fiducial
markers were implanted in 30 out of 56 lesions (54%). To
analyze respiratory tumor motion, 4D-CT scans were
performed for all patients. Gross tumor volume contours
of 10 breathing cycles were transferred to the average CT
of the CD-CT data, forming the internal target volume
(ITV). Planning target volume was obtained by adding a 4
mm margin. SBRT was delivered in VMAT technique using
Varian TrueBeam linear accelerator. Most common
fractionation schedule was 5 x 11 Gy (90% isodose covering
the PTV).
Results
The median follow-up for all patients was 13 months. The
overall local control rate for all 56 metastases was 86%
with a total of 7 failures. In univariate analysis, the
implantation of fiducial markers was predictive for local
control (p=0.029). During follow up period, tumor
progression developed in 28 cases (83%). In 13 cases new
intrahepatic lesions occurred (47%), in 10 cases extra
hepatic lesions (36%) and in 5 cases intra- and extra
hepatic lesions (18%). Overall survival rate was 58%,
median overall survival was 21 months. Univariate analysis
showed statistical significance for OS concerning histology
(colorectal vs. other) and gross tumor volume (</> 20
ccm).
Conclusion
Liver SBRT is effective and yielded good local control. The
SBRT procedure is a valid option for patients with
oligometastatic disease and should be considered as an
alternative to surgical treatment or other local ablative
techniques.
Electronic Poster: Clinical track: Lower GI (colon,
rectum, anus)
EP-1257 A look at pre-operative MRI accuracy at
predicting rectal cancer staging post
chemoradiotherapy
K. Nugent1, R. McDermott1, M. Higgins1, B. O'Neill1
1St Lukes Radiation Network, Radiation Oncology,
Dublin, Ireland
Purpose or Objective
Neoadjuvant chemoradiotherpy (CRT) has become
standard in the treatment of rectal cancer patients with