ESTRO 36 Abstract Book

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S203 ESTRO 36 2017
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MONDAY, 8 MAY 2017
Teaching Lecture: State of the art multimodality
treatment of rectal cancer
SP-0378 State of the art multimodality treatment of
rectal cancer
C. Rödel1
1 Klinikum der Johann Wolfgang Goethe Univ Frankfurt
univ hospital, Academic Department of Radiation
Oncology, Frankfurt, Germany
The monolithic approach to apply the same schedule of
preoperative 5-fluorouracil (5-FU)- or capecitabine-based
chemoradiotherapy (CRT), or short-course preoperative
radiotherapy, to all patients with clinically staged TNM
stage II/III rectal cancer need to be questioned. Five
randomized trials have been completed to determine if
the addition of oxaliplatin to preoperative 5-
FU/capecitabine-based CRT offers an advantage
compared with single-agent CRT. In contrast to the
German CAO/ARO/AIO-04 trial, results from the ACCORD
12, STAR-01, PETACC-6 and NSAPB R-04 trials failed to
demonstrate a significant improvement of early or late
efficacy endpoints with the addition of oxaliplatin. Most
of the phase II trials incorporating cetuximab into CRT
reported disappointingly low rates of pCR; the
combination of CRT with VEGF inhibition showed
encouraging pCR rates but at the cost of increased surgical
complications. Novel clinical trials currently address (1)
the role of induction and consolidation chemotherapy
before or after CRT, (2) minimal or omitted surgery
following complete response to CRT, or (3) the omission of
radiotherapy for selected patients with response to
neoadjuvant chemotherapy. The notion of different
multimodal treatment concepts according to tumor stage,
location, mesorectal fascia margin status, molecular
profiles, tumor response, and patients’ preferences
becomes increasingly popularand will render the
multimodal treatment approach of rectal cancer more
risk-adapted.
Teaching Lecture: SBRT for spine and non-spine bone
metastases: what role in routine practice?
SP-0379 SBRT for spine and non-spine bone
metastases: what role in routine practice?
M. Dahele1
1 VU University Medical Center, Amsterdam, The
Netherlands
Not all bone metastases, tumours and patients are equal -
the underlying theme of this session is a practical, more
personalized approach to the treatment of patients with
bone metastases.
Topics will include:
What is SBRT for bone metastases?
Do current clinical guidelines for the treatment of bone
metastases mention SBRT?
Why consider SBRT for bone metastases?
What data is there for spine and non-spine bone SBRT?
What are the options if there is no “high-level” data to
support using SBRT?
Is SBRT the only way to deliver high doses to bone
metastases?
What are some of the reasons for being cautious with SBRT
and high-dose radiotherapy for bone metastases?
What are some of the clinical challenges of bone SBRT?
What resources are needed to provide SBRT for bone
metastases?
Teaching Lecture: Challenges in proton radiotherapy
SP-0380 How to reduce range uncertainties
A. Knopf1
1Knopf Antje, Groningen, The Netherlands
Sources of range uncertainties [1]
- Imaging (CT imaging and calibration / CT conversion)
- patient setup
- intra-fractional changes
- beam delivery (measurement uncertainty during
commissioning)
- dose calculation (biology, mean excitation energy,
range degradation)
Monitor range uncertainties
- PET [2]
- Prompt gamma [3]
Correct for range uncertainties
-Range probe + adaptation
Range probe can be done in different ways
-Shoot through [4]
-CBCT [5]
-Implanted detectors [6]
Reduce range uncertainties
-Dual energy CT [7]
-Proton radiography [8]
-MC dose calculations [1]
References:
[1] Paganetti H (2012) Range uncertainties in proton
therapy and the role of Monte Carlo simulations. Phys
Med Biol. 57(11):R99-117
[2] Paganetti H and Fakhri G El (2015) Monitoring proton
therapy with PET. Br J Radiol. 88(1051): 20150173
1/
[3] Verburg J and Seco J (2014) Proton range verification
through prompt gamma-ray spectroscopy. PMB 59(23)
7089-7106
9155/59/23/7089/meta
[4] Mumot at al. (2010) Proton range verification using a
range probe: definition of concept and initial analysis.
PMB 55(16):4771-82
[5]
Bentefour el H (2015) Using CBCT for pretreatment range
check in proton therapy: a phantom study for prostate
treatment by anterior-posterior beam. J Appl Clin Med
Phys. 16(6):5212
[6] Bentefour el H (2015) Validation of an in-vivo proton
beam range check method in an anthropomorphic pelvic
phantom using dose measurements. Med Phys.
42(4):1936-47
[7] Moehler C et al. (2016) Range prediction for tissue
mixtures based on dual-energy CT. PMB 61(11):N268-75.
[8] Farace P et al. (2016) Pencil beam proton radiography
using a multilayer ionization chamber. PMB 61(11):4078-
87
Review articles:
Kraan AC (2015) Range Verification Methods in Particle
Therapy: Underlying Physics and Monte Carlo Modeling.
Front Oncol. 5:150
Knopf AC and Lomax A (2013) In vivo proton range
verification: a review. PMB 58(15):R131-60