ESTRO 36 Abstract Book

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S632 ESTRO 36 2017
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S.H. Liu1, Y.C. Huang2, Y.J. Chen 1
1 Mackay Memorial Hospital, Department of Radiation
Oncology, Taipei, Taiwan
2 Graduate Institute of Chinese Medical Science, China
Medical University, Taichung, Taiwan
Purpose or Objective
For patients with 4 or more lymph nodes involvement,
regional nodal irradiation (RNI) is associated with
increased locoregional control and overall survival (OS).
The main radiotherapy (RT) volume for RNI includes
axillary, supraclavicular, and/or internal mammary nodes.
However, whether the posterior supraclavicular area and
the posterior triangle of the neck (PSPT) should be
included in RNI remains unclear. The object of this study
was to retrospectively review our clinical experience of
RNI to PSPT or not in N2-3 breast cancer patients as a
reference for target delineation.
Material and Methods
Patients with N2-3 breast cancer who received definitive
surgery and/or neoadjuvant/adjuvant therapy during
2006–2013 were reviewed. The delivery of adjuvant RT and
the coverage for RNI were at the discretion of treating
physicians. To ensure precise delineation and dosimetry,
only patients treated using the technique of intensity-
modulated radiotherapy (IMRT) to regional nodal area
were enrolled. The patterns of recurrence including the
PSPT region were examined. The locoregional control rate
(LCR), distant metastasis-free rate (DMFR), disease-free
survival (DFS), and OS were analyzed using Kaplan-Meier
method, and survival estimates were obtained with log-
rank test and the Cox proportional hazard model.
Results
Of 256 N2-N3 breast cancer patients who were diagnosed
and received operation in a medical center, 184 cases
were eligible for the study. Among these women, 62
received RNI according to the recommended volume by
RTOG consensus (RC group), 57 had additional volumes of
PSPT (RC+PSPT group), and 65 did not have adjuvant RT
(NRT group). Median follow-up was 62.8 months for the
entire cohort. There was higher LCR (p=0.006, 90.8% vs.
78.5% at 5 years) and OS (p=0.007, 82.7% vs. 64.8% at 5
years) for the patients with adjuvant RT (RC and RC+PSPT)
compared to those without RT (NRT). No difference in
DMFR (p=0.508, 69.6% vs. 63.4% at 5 years) and DFS
(p=0.243, 68.2% vs. 69.2% at 5 years) were noted. Among
women with adjuvant RT, there was no statistical
difference between RC and RC+PSPT groups (LCR:
p=0.693, 93.1% vs. 89.9% at 5 years; DMFR: p=0.501, 66.2%
vs. 73.9% at 5 years; DFS: p=0.606, 66.2% vs. 71.6% at 5
years; OS: p=0.548, 83.5% vs. 83.5% at 5 years). In details,
locoregional recurrence was found in 4 (6.5%), 6 (10.5%),
and 17 (26.2%) patients in the RC, RC+PSPT and NRT group,
respectively. Among these patients, no PSPT recurrence
was noted in RC+PSPT group, whereas there were 2 (50%)
in the RC group and 11 (64.5%) in the NRT group.
Conclusion
Adjuvant RNI significantly increased LRC and OS for N2-N3
breast cancer patients. Local recurrence specifically
noted in PSPT might be diminished by additional inclusion
in the regional nodal irradiation volumes. This impact may
not translate to the changes in LCR, DMFS, DFS, and OS in
our experience. Further prospective investigation is
needed to validate these results with exclusion of possible
selection bias.
EP-1175 Impact of body-mass index on setup
displacement in patients with breast cancer
Y.C. Tsai1, C.Y. Chen2, J.T. Tsai1
1 Taipei Medical University-Shuang Ho Hospital, radiation
oncology, New Taipei City, Taiwan
2 Wan Fang Hospital- Taipei Medical University, Radiation
oncology, Taipei, Taiwan
Purpose or Objective
To determine the impact of body-mass indexfactors (BMIF)
on daily setup variations for patients with breast cancer
treated with adjuvant radiotherapy with daily image
guidance.before radiotherapy and changes
duringradiotherapy on the magnitude of setup
displacement in patients with breast cancer.
Material and Methods
The clinical data of 117 patients with breast cancer was
analyzed using the alignment data from daily on-lineon-
board imaging from image-guided radiotherapy between
2013 and 2015. All patients received cone beam computed
tomography(CBCT) at the first 5th fraction, then once per
week at least. BMFs included body weight, body height,
and thecircumference and bilateral thickness of the
neckThe shifts of each fraction were collected in superior-
inferior (SI), anterior-posterior (AP), and medial-lateral
(ML)directions respectively, and the absolute distant of
shifts was also calculated. The shifts of patients were
grouped by factors of BMI, body weight, height, age,
operation method and acute toxicities respectively. For
grouping of BMI,body weight and height, the median
values were used as cut off. The impact of factors as
assessed by compare the shifts using independent t-test
within each groups.
Results
Median BMI was 24.3, and median body weight was 59kg.
A higher body weight before radiotherapy correlated with
a greater shift in ML(p =0.0088 ), and SI(p = 0.0004)
direction. A larger BMI(≧ 24.3) was associated with a
greater shift in SI (p = 0.0005) direction. Comparsion of
patients undergoing breast-conserving surgery(BCS) and
modified radical mastectomy(MRM), BCS group was
associated with a larger shift in SI and ML(p=0.028 and
p=0.0051, respectively).
Conclusion
Larger body weight( ≧59kg, larger BMI(≧ 24.3) and BCS may
be a significant risk factor for daily shifts.
EP-1176 Helical tomotherapy in chest wall/breast and
draining node irradiation after breast cancer surgery
V. Lancellotta1, M. Iacco1, S. Chierchini1, E. Perrucci1, I.
Palumbo 1, L. Falcinelli1, S. Saccia 1, S. Nucciarelli1, A.
Milletti1, C. Aristei1
1Ospedale Santa Maria della Misericordia, Radiation
Oncology, Perugia, Italy
Purpose or Objective
Three dimensional conformal radiotherapy (3DCRT) to the
chest wall/breast and draining nodes has long
been standard treatment for patients at high-risk of
relapse after mastectomy or conserving surgery (BCS).
Given the complex target shape, other radiotherapy
techniques such as intensity modulated RT (IMRT),
volumetric modulated arc therapy (VMAT), helical (HT) or
direct (DT) tomotherapy were developed. The present
study evaluated the toxicity of HT for treating the chest
wall or breast plus level III and IV lymph nodes after
mastectomy or BCS.
Material and Methods
From January 2013 to August 2016, 43 consecutive
patients with breast cancer underwent helical
tomotherapy . Table 1 reports their demographics and
clinical details. Computed tomography (CT) scans without
contrast medium were acquired with patients supported
by breast board in the treatment position. CT data were
acquired with 2.5 mm slice thickness and were
transmitted to the Pinnacle 3 TPS V9.8. One radiation
oncologist contoured the clinical target volume (CTV) i.e.
chest wall or breast, level III and IV lymph nodes and
organs at risk. The chest wall was not expanded to obtain
the planning target volume (PTV); the breast and nodes
were expanded 0.5 cm in all directions to obtain the PTV
breast and PTV ln. Dose prescription was 50 Gy to the
PTVs in 25 fractions. In 7 patients treated with BCS a
simultaneous integrated boost (SIB) was delivered to the