ESTRO 36 Abstract Book

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S639 ESTRO 36 2017
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LAD is considered to be receiving a high dose when over
10% of the contoured volume received 20 Gy or more.
Results
For all 32 patients, the plans are acceptable based on the
criteria for whole heart and LADarch. The results of this
study showed that the mean doses to the three cardiac
structures are 1,88 (range, 1,25-3,98 Gy) for the heart,
7.3 (range, 3,82-17,15 Gy) for the LADarch and 9,64 (range,
3,24-27,84 Gy) for the LAD.
Most important results shows, that for 11 patients the
heart Dmean was only 2,15 (range, 1,37 - 3,98), while a
significant dose to the whole left anterior descending
interventricular branch being delivered.
We found 4 cases, in which the dose to the LADarch was
with marginal increase, but significant portion of the heart
and whole LAD is included in the field. There were no
cases where the dose to the LAD arch, LAD and whole heart
dissociated. But in 7 cases the dose to the LADarch was
relatively low, however the dose to the whole LAD was
significantly higher (14,6-37,6% of the contoured volume
received over 20 Gy).
Conclusion
Evaluation of the mean dose to the heart only could lead
to excessive heart irradiation. The results of the study
indicate that it is necessary to assess the dose delivered
to the whole heart as well as to the whole LAD for
evaluation of the left breast irradiation treatment plan.
This is very important to minimise the risk of clinically
significant cardiac events after left breast radiotherapy.
EP-1191 Postmastectomy locoregional irradiation to
temporary tissue-expander or permanent breast
implant
M.A. Gerardi 1, D.P. Rojas2, R. Ricotti1, M.C. Leonardi1, G.
Riva 2, D. Ciardo1, C.M. Francia 2, R. Cambria3, R.
Luraschi3 , F. Cattani3, C. Fodor 1, F. De Lorenzi4, M.
Rietjens4, P. Veronesi 5, A. Morra 1, V. Dell'Acqua1, R.
Orecchia6, B.A. Jereczek-Fossa2
1 European Institute of Oncology, Department of
Radiation Oncology, Milan, Italy
2 European Institute of Oncology - University of Milan,
Department of Radiation Oncology - Department of
Oncology and Hemato-oncology, Milan, Italy
3 European Institute of Oncology, Department of Medical
Physics, Milan, Italy
4 European Institute of Oncology, Department of Plastic
and Reconstructive Surgery, Milan, Italy
5 European Institute of Oncology, Department of Surgery,
Milan, Italy
6 European Institute of Oncology - University of Milan,
Department of Medical Imaging and Radiation Sciences -
Department of Oncology and Hemato-oncology-, Milan,
Italy
Purpose or Objective
The aim of the study (partially supported by a research
grant from Accuray Inc. entitled 'Data collection and
analysis of Tomotherapy and CyberKnife breast clinical
studies, breast physics studies and prostate study”) is to
evaluate acute and intermediate toxicity in
postmastectomy patients with implant-based immediate
breast reconstruction receiving locoregional intensity
modulated radiotherapy (IMRT) with a hypofractionated
scheme.
Material and Methods
Data of the first 121 consecutive post-mastectomy
locoregional patients treated with Helical Tomotherapy
between May 2012 and May 2015 with a hypofractionated
scheme (2.67Gy/fr, 15 fractions) have been prospectively
collected. Breast reconstruction was performed with
temporary tissue expander implantation in 57% of patients
(69/121 expander-patients) and with permanent
prosthesis in 43% of patients (52/121 prosthesis-patients).
Acute toxicity was evaluated using RTOG/EORTC criteria,
while late toxicity was recorded according to LENT/SOMA
scale.
Results
All patients completed the treatment course without
interruption for toxicity. In the expander group, one
patient died for leukemia 20.3 months after radiotherapy
and two had distant metastasis.Acute toxicity was
assessed in 121 patients (mean follow up: 2.4 months,
range: 0-8.1 months). No patient experienced grade >2
toxicities (edema, erythema or desquamation). No
significant difference (p=0.06) in acute toxicities were
observed between the type of allogenic reconstruction:
43.5% (30/69) of expander-patients and 26.9% (14/52) of
prosthesis-patients presented toxicities of grade 2. The
most common toxicity was edema, which was of grade 2
in 33.3% (23/69) of the expander-patients and 21.2%
(11/52) of prosthesis-patients (p=0.141). Grade 2 acute
erythema was observed in 14.5% (10/69) of expander-
patients and 7.7% (4/52) of prosthesis-patients (p=0.249).
Statistically significant (p=0.04) higher incidence of grade
2 edema was found in patients with high BMI. This was
found also in the prosthesis-patient subgroup
(p=0.05).Intermediate toxicity was evaluated at a median
follow up of 14.2 months (range: 5.8-35.0) on 85 patient
(54 expander-patients and 31 prosthesis-patients). No
grade ≥2 skin dryness, telangiectasia, ulcer, hypo- and
hyper-pigmentation were reported (Tab.1).
Conclusion
Acute toxicity of Helical Tomotherapy-based IMRT after
immediate breast reconstruction was satisfactory and
intermediate toxicity was acceptable. Based on this
preliminary analysis, hypofractionation might be
considered also in the settings of locoregional treatments,
providing advantages for patients’ convenience and for
fruitful use of resource.
EP-1192 Assessment of quality of life in phase III
clinical trials of radiation therapy in breast cancer
G.N. Marta1,2, F.Y. Moraes3, E.T. Leite 2, E. Chow4, D.
Cella 5, A. Bottomley6
1Hospital Sírio-Libanês, Radiation Oncology, São Paulo,
Brazil
2Instituto do Câncer do Estado de São Paulo ICESP -
Faculdade de Medicina da Universidade de São Paulo,
Radiation Oncology, Sao Paulo, Brazil
3Princess Margaret Cancer Center- University of Toronto,
Radiation Oncology, Toronto, Canada
4Sunnybook Odette Cancer Centre- Sunnybrook Health
Sciences Centre, Radiation Oncology, Toronto, Canada
5Northwestern University, Medical Social Sciences,