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ESTRO 36
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EP-1151 Hypofractionated Radiotherapy in breast
cancer treatment: A comparison between 3-DCRT and
IMRT
A. Fiorentino
1
, R. Mazzola
1
, N. Giaj Levra
1
, G. Sicignano
1
,
G. Di Paola
1
, S. Naccarato
1
, S. Fersino
1
, U. Tebano
1
, F.
Ricchetti
1
, R. Ruggieri
1
, F. Alongi
1
1
Sacro Cuore Don Calabria Hospital, Radiation Oncology
Department, Negrar, Italy
Purpose or Objective
to compare 3-Dimensional Conformal RadioTherapy (3D-
CRT) and 4-fields Intensity Modulated RadiationTherapy
(IMRT) treatment plans, in terms of target dose coverage,
integral dose and dose to Organs at risk (OARs) in early
breast cancer (BC) hypofractionated RT.
Material and Methods
Twenty consecutive patients with early BC, after
lumpectomy, were selected for the present analysis. A
total dose of 40.5Gy in 15 fractions was prescribed to
Planning Target Volume (PTV
breast
) of the whole breast,
while a simultaneous total dose of 48Gy was prescribed to
the PTV of the surgical bed (PTV
boost
). For each patient
both a 3D-CRT plan with two couples of tangential-fields,
and a 4-fields sliding-window IMRT plan were generated.
Conformity and homogeneity indexes (CI, HI) were
calculated for PTVs. For evaluation of OARs and normal
tissue (NT), V
5Gy
, V
10Gy
and various organ specific V
xGy
values were analyzed.
Results
In terms of HI, IMRT (0.18 ± 0.02) was superior to 3D-CRT
(0.23 ± 0.02) for the PTV
breast
(p<0.0001). Both techniques
achieved the required dose for the PTV
boost
coverage, but
a significant difference for CI was observed in favour of
IMRT (0.9 ± 0.4) compared to 3D-CRT (3.7 ± 4.3)
(p<0.0001). With regards to the heart, IMRT improved both
mean and near-maximum doses. The inter-patients
average of the heart D
mean
was (1.9 ± 1) Gy for 3D-CRT,
and (1 ± 0.8) Gy for IMRT (p < 0.0001). For the analysis of
left BC, the inter-patients average of the heart D
mean
was
(2.9 ± 0.8) Gy for 3D-CRT, and (1.7 ± 0.6) Gy for IMRT (p =
0.0005). For the ipsilateral lung, the average of D
mean
for
overall patients was 6.3 ± 1.4 Gy with 3D-CRT, and 4.8 ±
1.3 Gy with IMRT (p<0.0001). The V
25Gy
value of the
ipsilateral lung was also lower with the use of IMRT
(p<0.0001). For the contralateral lung, the inter-patients
median of D
mean
to the contralateral lung was 0.4Gy for 3D-
CRT and 0.08Gy for IMRT (p<0.0001). For the contralateral
breast, both D
mean
and D
2%
were improved by the use of an
IMRT planning technique. The inter-patients average of
D
mean
was (0.3 ± 0.3) Gy for IMRT, while (1 ± 0.5) Gy for 3D-
CRT (p <0.0001). For NT
,
all DVH parameters are in favor
of IMRT, except the V
5Gy
for which the difference was not
statistically significant. The mean value of D
mean
was 2.2 ±
0.6 for 3D-CRT and 1.5 ± 0.4 for IMRT (p < 0.0001).
Conclusion
IMRT technique significantly reduced the dose to OARs and
NT, with a better target coverage compared to 3D-CRT.
Clinical evaluations are advocated.
EP-1152 Intraoperative radiotherapy for early breast
cancer: a monocentric experience
A. Baldissera
1
, L. Giaccherini
2
, I. Marinelli
3
, A. Parisi
4
, G.
Siepe
2
, O. Martelli
1
, F. Salvi
1
, D. Balestrini
1
, C. Degli
Esposti
1
, I. Ammendolia
2
, G. Tolento
2
, V. Panni
2
, G.
Macchia
5
, F. Deodato
5
, S. Cilla
6
, A.G. Morganti
2
, G.P.
Frezza
1
1
Ospedale Bellaria, Radiotherapy Department, Bologna,
Italy
2
University of Bologna, Radiation Oncology Center-
Department of Experimental- Diagnostic and Specialty
Medicine - DIMES, Bologna, Italy
3
Sapienza University, Radiation Oncology Department,
Rome, Italy
4
Istituto Oncologico Veneto IRCCSS, Radiation Oncology
Department, Padua, Italy
5
Fondazione di Ricerca e Cura “Giovanni Paolo II”,
Radiotherapy Unit, Campobasso, Italy
6
Fondazione di Ricerca e Cura “Giovanni Paolo II”,
Medical Physics Unit, Campobasso, Italy
Purpose or Objective
Single-dose intraoperative radiotherapy (IORT) is an
alternative treatment for selected cases of early stage
breast cancer. The purpose of this study is to present
preliminary results of patients treated with IORT at
Bellaria Hospital, Bologna, Italy
Material and Methods
We analysed data of 108 women who underwent
lumpectomy and IORT with primary intent. IORT
treatment was performed with a dedicated mobile
electron accelerator (21 Gy were prescribed at 90%
isodose). Data collected were histopathology, adjuvant
treatment, clinical tolerability, local recurrences and
outcomes.
Results
From December 2011 to December 2015, 108 women
(median age 72 years) were treated with IORT. 75% of
patients were treated with adjuvant ormonotherapy and
11.1% with combined chemotherapy plus hormonotherapy.
The median follow-up was 26 months (range 2-52). 82.4%
of patients had disease that was <2 cm in size, 65.7% of
patients had an infiltrative duct carcinoma. At the end of
follow-up 89.9% had a G0-G2 grade of late parenchymal
fibrosis and 69.4% of patients a good cosmetic result. One
patient underwent a mastectomy after five months
because of chronic fistula in the irradiated area. One
patient had a local relapse in a different quadrant and one
patient had an axillary lymph node recurrence. Only one
patient developed systemic metastasis. One patient died
from breast progressive disease.
Conclusion
IORT represents a safe and effective alternative treatment
option in selected patients with early breast cancer. Low
complication rate with good clinical and cosmetic
outcomes support IORT as a treatment option for selected
women.
EP-1153 Post-Mastectomy Hypofractionated
Radiotherapy for Breast Cancer Treatment
C.S. Ortiz Arce
1
, A. Chagoya González
2
, E.N. Barrientos
Luna
2
1
Hospital Regional de Alta Especialidad Bajío,
Radiotherapy, León, Mexico
2
Centro Médico Nacional Siglo XXI- IMSS, Radiotherapy,
Mexico City, Mexico
Purpose or Objective
Radiotherapy (RT) for Breast Cancer improves local
control and provides benefit in overall survival; this is
given mainly in daily fractions (Fx) over a period of 5-6
weeks.
Hypofractionated schedules reduce the number of
sessions,
shortening
the
treatment
time.
Many studies reported local recurrence in patients treated
with breast-conserving surgery (BCS) with less than 5% in
a lapse of
5
years.
However, the indication of a hypofractionated scheme
after a Modified Radical Mastectomy (MRM) is not clearly
established, since there is only one study with a 7-year
follow-up which reported 3 patients with local recurrence.
Due to the high number of patients requiring RT, we
initiated this transversal and comparative study, at the
Centro
Médico
Nacional
Siglo
XXI,
IMSS.
We compared hypofractionated and conventional
schedules in order to evaluate acute toxicity and local