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ESTRO 36 2017
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Teaching Lecture: Target delineation and target
definition for Partial Breast Irradiation after closed
cavity surgery and oncoplastic surgery
SP-0008 Target delineation and target definition for
Partial Breast Irradiation after closed cavity surgery and
oncoplastic surgery
V. Strnad
1
1
University Clinic Erlangen, Dept. Radiation Oncology,
Erlangen, Germany
Objective:
To define in CT images tissue structures inside
the breast after a breast conserving surgery, which make
possible reproducible delineate Clinical Target Volume
(CTV) and Planning Target Volume (PTV). The results of
deliberations of Breast Working Group of GEC-ESTRO and
corresponding recommendations for target definition for
APBI will be presented.
Recommendations:
The Working Group Breast of GEC-
ESTRO recommend to have for the correct delineation of
CTV (PTV) appropriate knowledge’s and to perform steps
As follow:
1. To hold
DETAILED KNOWLEDGE’
S about anatomy of
the breast of patient and of the tumor, about primary
surgical procedure particularly type of surgery, use -
number and location of surgical clips, position of the skin
scar ), of pathological report (particularly size of resection
margins in at least 6 directions, of preoperative
mammography, MRI and ultrasound.
2. Identification of the
TUMOR LOCALIZATIO
N before
breast conserving surgery inside the breast and translate
this information in current CT imaging data set.
3. Calculation of the size of
SAFETY MARGINS
needed to
cover CTV in all 6 directions. The appropriate size of
safety margins (surgical resection margins and adapted
safety margins) should be at least 2 cm.
4.
DEFINITION OF TARGET
5.
DELINEATION OF THE TARGET
according defined
rules. We recommend following seven steps for target
delineation after closed cavity surgery:
a. Perform a CT.
b. Delineation of clips.
c. Delineation of surgical bed – whole surgical scar (WS)
inside breast.
d. Delineation of ImTV (Imaging correlated Target
Volume).
e. Delineation of ETB (Estimated Tumour Bed).
f. Delineation of CTV (Clinical Target Volume).
g.Delineation of PTV (Planning Target Volume).
For target definition after oncoplastic surgery dissident
from recommendation for target definition after “closed
cavity surgery” the Clinical target volume (CTV) is
defined as the sum of the relevant clipped area (RCA).
Conclusion:
Presented guidelines makes possible a
reproducible and robust definition of CTV (PTV) for
Accelerated Partial Breast Irradiation (APBI) or boost
irradiation after breast conserving closed cavity or
oncoplastic surgery.
SP-0009 Target delineation and target definition for
PBI after open cavity surgery
T. Major
1
, C. Polgár
1
1
National Institute of Oncology, Radiotherapy Centre,
Budapest, Hungary
Objective
: To present guidelines for target definition and
delineations after open cavity breast conserving surgery in
accelerated partial breast irradiations or boost treatments
using multicatheter interstitial brachytherapy based on
the consensus of the GEC-ESTRO Breast Cancer Working
Group.
Method:
As a first step a contouring study with two phases
was conducted by the Working Group. Contours of cavity
and PTV on pre- and postimplant CT images were
delineated. In Phase 1 nine radiation oncologists defined
the target volumes of five patients without any
instructions, while in Phase 2 four observers draw the
contours of four patients applying simple contouring rules.
The delineations were compared between the two phases,
the impact of guidelines was assessed and cavity
visualization score was related to consistency of
delineations. Following the study on interobserver
variations of target volume delineation and a number of
discussions in consensus meetings guidelines were worked
out by experts on the field.
Recommendations
: (1) Consistent windowing has to be
used for proper cavity visualization. (2) The cavity
visualization score has to be at least 3 in order to minimize
the interobserver variations of target definition. (3) At
delineation of surgical cavity only the homogeneous part
of the postoperative seroma has to be included in the
contours and protrusions or sharp irregularities have to be
excluded. When surgical clips are present, they have to be
surrounded by the contour with close contact. (4) CTV is
created from the outlined surgical cavity with a non-
isotropic geometrical extension. In each direction the
safety margin is calculated by taking into account the size
of free resection margin. The total size of safety margin is
always 20 mm which is the sum of the surgical and added
safety margins. CTV is limited to chest wall/pectoral
muscles and 5 mm below the skin surface.
Conclusion
: It has been demonstrated that simple rules on
defining the lumpectomy cavity significantly increased the
consistency of contouring. Reliable consistency of target
volume definition can be expected only for good cavity
visibility. Following the GEC-ESTRO guidelines it is
expected that the target volume definition in breast
brachytherapy after open cavity surgery will be
accomplished with more consistent way among radiation
oncologists with low interobserver variations.
Joint Symposium: ESTRO-ASTRO: Cutting edge
combined modality therapies (Focus on NSCLC)
SP-0010 The gains to be made by combined modality
treatment in NSCLC: setting the scene of new
possibilities
M. Stuschke
1
, C. Poettgen
1
1
Universitätsklinikum Essen, Radiotherapy, Essen,
Germany
Concurrent radiochemotherapy or combined modality
treatments including surgery are standard options for
stage IIIA NSCLC and stage IIIB patients treated with
curative intent. Cumulative incidences of loco-regional
recurrences approach 30% at 5 years following standard
concurrent 60 Gy radiochemotherapy with conventional
fractionation, while tri-modality schedules showed loco-
regional recurrences of about 15%. Dose escalation using
conventional fractionation and concurrent platin-based
chemotherapy within the RTOG 0617 trial has failed to
show a benefit in survival or local control. Passive
scattering Proton therapy did not show a reduction in the
rate of radiation pneumonitis in comparison to intensity
modulated photon radiotherapy at the same total dose
according to the NCT 00915005 trial. So where are the
promising ways to improve survival of patients with locally
advanced lung cancer by technological advances in
radiotherapy?
More sensitive methods are needed to detect tumor
spread
and
beyond
FDG-PET/CT.
Systematic
endobronchial ultrasound-guided transbronchial needle
aspiration can improve sensitivity to detect lymph node
metastases. Prognostic factors for tumor control and
toxicity after concurrent radiochemotherapy are being
established to individualize dose escalation. PET-
response, tumor volume, and dose volume histogram