ESTRO 36 Abstract Book

355 / 1082

S340 ESTRO 36 2017
_______________________________________________________________________________________________
simple mastectomy were the main surgical approaches
(69.9%). Skin-sparing and nipple-sparing mastectomy were
performed in 29.7%. Immediate reconstruction was done
in 94% of patients, 85% with tissue expander with included
or remote valve. The average volume expansion was
546.2 ml. Post-operative RT was performed in 162 patients
(66.4%) with prescribed dose of 50 or 50.4Gy in 92.3%.
Early complications were seen in 125 patients (50.8%), of
which 25% required reoperation and 18.3% of the patients
lost the implant. Local infection was significantly
correlated with severe early complications. Only 10
patients (4.1%) had late complications. Of these, 8
underwent post-operative RT (5% of irradiated patients)
and 2 (2%) were not irradiated (p = 0.327). In the
univariate analysis, diabetes mellitus, smoking,
neoadjuvant chemotherapy, expander with included
valve, age over 50 years, BMI > 25 kg/m2 were related to
early toxicity (p < 0.05). In multivariate analysis, besides
obesity, diabetes mellitus, expander with included valve
and not performing neoadjuvant chemotherapy remained
as variables related to early toxicity (p < 0.05). No
correlation of the studied clinical variables with late
toxicities was observed. RT was not related to high risk of
early and late toxicities.
Conclusion
Approximately 50% of patients with alloplastic breast
reconstruction presented early complications. Late
complications were low in this population. RT did not
increase the risk of severe complications after alloplastic
breast reconstruction.
PO-0659 Hypofractionated-accelerated concomitant
boost in moderate-high risk breast cancer:phase I-II
study
M. Boccardi1, G. Macchia 1, F. Deodato1, M. Ferro1, S.
Cilla2, A. Ianiro 2, S. Cammelli3, A. Farioli4, D. Smaniotto5,
A.L. Angelini 6, A. Di Stefano7, G.P. Frezza8, I.
Ammendolia3, G. Tolento3, A. Zamagni3, V. Valentini5,
A.G. Morganti3
1 Fondazione di Ricerca e Cura "Giovanni Paolo II",
Radiotherapy Unit, Campobasso, Italy
2 Fondazione di Ricerca e Cura "Giovanni Paolo II",
Medical Physics Unit, Campobasso, Italy
3 University of Bologna, Radiation Oncology Center-
Department of Experimental- Diagnostic and Speciality
Medicine - DIMES, Bologna, Italy
4 University of Bologna, Department of Medical and
Surgical Sciences - DIMEC, Bologna, Italy
5 Policlinico Universitario "A. Gemelli"- Università
Cattolica del Sacro Cuore, Department of Radiotherapy,
Rome, Italy
6 University of Bologna- S. Orsola-Malpighi Hospital,
Medical Physic Unit, Bologna, Italy
7 Fondazione di Ricerca e Cura "Giovanni Paolo II",
Gynecologic Oncology Unit, Campobasso, Italy
8 Ospedale Bellaria, Radiotherapy Department, Bologna,
Italy
Purpose or Objective
To evaluate the results in terms of local control and late
toxicity using intensity modulated radiotherapy with
concomitant boost in breast cancer (BC). These results
were compared with a control group (CG) of patients
treated with standard 3-dimensional (3-D) radiotherapy
plus sequential boost.
Material and Methods
Primary endpoint was local control. Secondary endpoints
were late skin and subcutaneous toxicities. Patients with
moderate-high risk (≥ 3 axillary nodes and/or pre- or peri-
menopausal status and/or close resection margins) were
enrolled and treated with forward-planned IMRT
technique. Prescribed dose to the breast was 50 Gy in 25
fractions (fx) with a concomitant boost to the tumor bed
of 10 Gy. In CG group, whole breast received a total dose
of 50.4 Gy in 28 daily fx with a sequential boost to the
tumor bed of 10 Gy in 4 fx. Late skin and subcutaneous
toxicity were evaluated using Radiation Therapy Oncology
Group / European Organization for Research and
Treatment Cancer (RTOG/EORTC) scoring scale.
Results
Four hundred and fifty one patients were included in our
analysis (MARA-2: 321; CG:130). Median follow up was 52
months (range: 3-115). Five-year local control was 96.7%
and 97.6% in CG and MARA-2 groups, respectively
(p=0.676). At univariate analysis, patients treated with
concomitant boost (MARA-2) showed a significant increase
of late G1 and G2 subcutaneous toxicity (p<0.001). Five-
year G1 subcutaneous late toxicity free-survival (LTFS)
were 73.4% and 38.5% in CG and MARA-2, respectively.
Moreover, 5-year G2 subcutaneous LTFS were 96.5% and
80.0% in CG and MARA-2, respectively. Five-year actuarial
cumulative incidence of G3 late subcutaneous toxicity was
0.0% and 0.9% in CG and MARA-2, respectively. G1 and G2
late skin toxicities were similar in the two groups and no
patients showed G3 ≥ late skin toxicity in MARA-2.
Conclusion
This study showed the feasibility of concomitant boost
using IMRT technique in postoperative radiotherapy of BC
with reduction of treatment duration and without
significant increase of G > 2 late effects. Local control was
excellent despite inclusion criteria.
PO-0660 Partial breast re-irradiation with IMRT in
patients with local failure after conservative treatment
S. Dicuonzo1, R. Spoto1, M.C. Leonardi2, A. Surgo3, A.
Viola 1, M. Augugliaro1, F. Pansini4, F. Cattani4, V.
Galimberti5, A. Morra2, V. Dell'Acqua2, R. Orecchia6, B.A.
Jereczek-Fossa 1
1European Institute of Oncology-University of Milan,
Department of Radiation Oncology-Department of
Oncology and Hemato-oncology, Milan, Italy
2European Institute of Oncology, Department of
Radiation Oncology, Milan, Italy
3European Institute of Oncology-University of Milan,
Department of Radiation Oncology-Department of
Oncology and Hemato-oncology affiliation at the time of
the study, Milan, Italy
4European Institute of Oncology, Department of Medical
Physics, Milan, Italy
5European Institute of Oncology, Department of Surgery,
Milan, Italy
6European 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 is to evaluate acute and intermediate
toxicity and clinical outcome of partial
breast re-irradiation (re-PBI) with intensity-modulated
radiotherapy (IMRT), using hypofractionation.
Material and Methods
This is a prospective clinical study including patients (pts)
previously treated with whole breast radiotherapy (WBRT)
who experienced in-breast tumor recurrence and
underwent a second conservative surgery. Re-irradiation
was limited to the tumor bed. Intensity modulated re-PBI
was performed using Tomotherapy in helical modality or
BrainLab-VERO step-and-shoot modality. Planning target
volume (PTV) was generated by clinical treatment volume
(CTV) with an isotropic margin expansion of 5 mm. Daily
image guided irradiation was performed (megavoltage fan
beam computerized tomography (CT) for Tomotherapy
and kilovoltage cone beam CT for VERO). Planning
objectives for PTV coverage were: V100% ≥95%, V95%≥98%,
D 0,03cc≤110%. Acute toxicity was evaluated using
RTOG/EORTC criteria, while late toxicity was recorded
according to LENT/SOMA scale.