ESTRO 36 Abstract Book

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S525 ESTRO 36
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funduscopic images MRI can be used to better assess the
delivered doses to the target and the organs-at-risk (OAR).
The main goal of this feasibility study is to demonstrate
that fundus mapping and post implantation MR imaging
can be incorporated into the treatment planning workflow
of 106Ru plaque brachytherapy.
Material and Methods
Patients were scanned in a 0.35 T MR scanner (Magnetom
C! Siemens, Germany) after 106Ru eye plaque implantation.
To achieve a good normal tissue contrast for tumor
delineation and organ-at-risk (OAR) segmentation a fast
low angle shot (FLASH) T1 weighted sequence was utilized
(TR = 15 ms, flip-angles = 25°). A second FLASH MRI scan
with lower repetition times (TR = 11.2 ms) and flip-angles
(20°) was applied in order to display the plaque as a well-
defined void with minimal distortion artifacts at the cost
of lower signal to noise ratio and less soft tissue contrast.
Based on the MRI the resizable 3D eye model of a newly
developed treatment planning software (described in
detail in [1]) was adapted to the individual patient
anatomy in terms of size and plaque position.
Furthermore, the funduscopy image was projected onto
the retina of the digital 3D eye model.
Results
The presented method using two MR sequences yielded 3D
image sets that allowed segmenting both the anatomical
structures and the 106-Ru plaque. The funduscopy image
on the other hand is the optimal modality for tumor
segmentation. By combination the 3D eye model can be
adapted to match the individual patient and thus allow for
individual treatment planning and dose calculation (based
on MR anatomy) where the post-implantation imaging
accounts for the actual position of the plaque with respect
to the target and critical structures. This way irradiation
times can be calculated which guarantee full tumor
coverage. Moreover, the workflow can be applied for
treatment plan optimization strategies where plaques are
shifted in order to reduce doses to OARs.
Conclusion
In this feasibility study it was shown that MRI in
combination with funduscopy can be used to optimize
brachytherapy with 106Ru plaques. The additional spatial
information on plaque position relative to critical
structures, tumor geometry as well as position can be used
for more precise dose calculations and therefore improved
treatment planning.
References:
[1] G. Heilemann et al. Treatment plan optimization and
robustness of 106Ru eye plaque brachytherapy using a novel
software tool. Radiotherapy and Oncology. (in revision)
Poster: Brachytherapy: Miscellaneous
PO-0948 Role of HDR Intraluminal Brachytherapy in
carcinoma Esophagus: An institutional experience.
P.B. Kainthaje1, P. Gaur1 , A. Malavat1, R. Paliwal1, V.
Sehra1
1 Dr. Sampurnanand Medical College, Department of
Radiotherapy, Jodhpur, India
Purpose or Objective
To study the profile of patients of Carcinoma Esophagus
treated with Intraluminal Brachytherapy (ILBT), the
outcome of the treatment in terms of response
assessment, toxicity and survival.
Material and Methods
The study period was between January 2014 and June
2015, with 25 patients of carcinoma esophagus middle
third, treated with ILBT either as part of definitive
Radiotherapy or as part of palliative Radiotherapy. The
patients with unifocal disease ≤10cm in length and with no
recorded intra-abdominal or distant metastases received
definitive Radiotherapy with 44Gy/22Fr through EBRT with
concurrent Cisplatin and 5-Flurouracil followed by,
10Gy/2Fr of ILBT boost once weekly. The patients with
local advanced disease for palliation received 36Gy/12Fr
through EBRT followed by, 10Gy/2Fr of ILBT once weekly.
The outcome of treatment was assessed in terms of
dysphagia score, dysphagia free survival, toxicities and
overall survival.
Results
Median age of patients was 55 years. Histopathologically
96 % has Squamous cell carcinoma. 16 (64%) of patients
were treated with definitive radiotherapy while the rest,
9 (36%) with palliative intent. At a median follow up of 9
months, 13 patients were dysphagia free and there were
5 deaths. One month after completion of treatment, 18
patients were dysphagia free while, 2 patients had partial
relief and 5 patients did not notice any relief in dysphagia.
2 patients died within 6 months of completion while, 2
patients developed trachea-esophageal fistula during
follow-up.
Conclusion
ILBT is a safe modality for boost in treatment of carcinoma
esophagus provided, the patients are sele cted with
caution.
PO-0949 Evaluation of role of Interstitial
Brachytherapy in Soft Tissue Sarcoma: Single institute
experience
V. Pareek1
1Jupiter Hospital- Thane, Radiation Oncology, Mumbai,
India
Purpose or Objective
Soft tissue Sarcomas are rare group of solid tumors
comprising of 1% of all solid tumors. The management of
soft tissue sarcomas have evolved due to advancements in
imaging, histopathology, cytogenetics, and the use of
multimodality treatment. The treatment strategies
emphasizes on the control of disease locally, sparing of
limb function and improvement in the quality of life. High
dose brachytherapy has formed a part of the management
and has the advantage of providing concentrated dose to
tumors and sparing of surrounding normal tissues. In this
study we examined the clinical outcome of High dose
Brachytherapy for STS at our Hospital through
retrospective analysis of the prospective database
maintained.
Objectives: To review the clinical outcome and quality of
life in patients with Soft Tissue Sarcoma treated at our
center through High dose rate interstitial brachytherapy.