ESTRO 36 Abstract Book

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S341 ESTRO 36 2017
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Results
Between 6/2012 and 11/2015, 48 pts were treated with
re-PBI. Median time to recurrence was 137.3 months (
range: 25.6-319 months). Prescription dose was 37.05 Gy
in 13 fractions. 9 pts were treated with Tomotherapy and
39 pts with VERO. Median age was 60.7 years. The patterns
of recurrences were as follows: in 37 cases site of
recurrence was the same as the index tumor
(true/marginal miss), while in the remaining 17 cases
recurrence occurred far from the index quadrant across
the breast (elsewhere in breast reappearance). Acute
toxicity was moderate: no acute toxicity >G2 was observed
at the end of the treatment (erythema G1 in 48% of pts;
desquamation G1 in 2% of pts; edema G2 in 8% of pts). Late
toxicity according to LENT/SOMA was available for 15/48
patients (Tab.1). All but one had G1-G2 toxicity: one
patient experienced G3 retraction. Overall, median
follow-up after first relapse was 22.1 months. 45 pts are
alive without disease while 3 pts showed distant
metastasis (DM). Median time to DM event was 12 months
and 3/3 have had true/marginal miss local recurrence with
high Ki-67.
Conclusion
Second conservative surgery combined with additional
radiotherapy represents a feasible alternative to
mastectomy. None of the patients relapsed locally.
Furthermore, good acute toxicity profile and an
acceptable early chronic toxicity were observed, although
longer follow-up and higher number of pts are needed to
confirm these results.
PO-0661 Intraoperative partial breast re-irradiation: a
multicenter study of the AIRO IORT Working Group
M.C. Leonardi1, G.B. Ivaldi2, M. Alessandro3, G.
Catalano4, A. Ciabattoni5 , C. Fillini6, M. Guenzi7, L.
Tomio8, D.P. Rojas9 , M. Augugliaro9, C. Fodor1, C.
Sangalli1, F. Rossetto1, B.A. Jereczek –Fossa9, R.
Orecchia10, AIRO IORT Working Group11
1 European Institute of Oncology, Department of
Radiation Oncology, MIlan, Italy
2 Fondazione Salvatore Maugeri, Oncology Unit, Pavia,
Italy
3 Ospedale di Città di Castello, Radioterapia Oncologica,
Città di Castello, Italy
4 Multimedica Holding Clinical Institute, Unit of
Radiotherapy, Castellanza, Italy
5 San Filippo Neri Hospital, Department of Radiotherapy,
Rome, Italy
6 Azienda Ospedaliera Santa Croce e Carle, Department
of Radiation Oncology, Cuneo, Italy
7 IRCC Azienda Ospedaliero-Universitaria San Martino IST,
UOC Oncologia Radioterapica, Genoa, Italy
8 Santa Chiara Hospital, Radiotherapy Unit, Trento, Italy
9 European Institute of Oncology - University of Milan,
Department of Radiation Oncology - Department of
Oncology and Hemato-oncology, Milan, Italy
10 European Institute of Oncology - University of Milan,
Department of Medical Imaging and Radiation Sciences -
Department of Oncology and Hemato-oncology, Milan,
Italy
11Associazione Italiana Radioterapia Oncologica,
intraoperative radiotherapy working group, -, Italy
Purpose or Objective
To assess the outcome after salvage breast conservative
surgery (BCS) and additional partial irradiation (PBI) with
intraoperative electrons (IORT) in patients previously
treated with BCS and whole breast irradiation.
Material and Methods
From 1999 and 2015, 115 patients affected by in-breast
recurrence (IBTR) were treated with salvage BCS and IORT
in 8 Italian centers. Data were collected centrally and
entered in a dedicated database. The study was promoted
and supported by the IORT Working Group of Italian
Association of Radiation Oncology (AIRO). Patients gave
informed consent for the use of anonymized data for
research and training purposes. Efficacy of re-treatment
was evaluated by means of second IBTR and distant
metastases (DM) rates. Tolerability was assessed based on
the incidence of postoperative complications. Systemic
treatment was given according to biologic profile and
institution’s policy.
Results
Median time to salvage BCS was 122 months (12-334). Site
of IBTR was the same as the index tumor in 44.3% of cases.
Median age at first BCS was 56 (37-76), while at salvage
BCS was 62 years (40-81). Patients received lumpectomy
only in 53% of cases, while axillary dissection was
performed in 3.2% of cases. The remaining patients had
sentinel node biopsy. In 43.4% of cases, the size of
recurrence was comprised between 1 and 2 cm. The
majority of patients had positive hormonal receptors,
22.6% had grade 3 tumors and in about half of the cases
Ki-67 was higher than 20%.
Regarding technical characteristics, IORT dose was 18-21
Gy in 82.6% of cases, median collimator size was 5 cm (3-
6 cm), median electron energy was 7 MeV. Main
postoperative complications after IORT delivery consisted
of lyponecrosis ( 4.3%), hematoma (6.9%), seroma (8.7%),
edema (6.9%), infection (2.6%). At a median follow-up
after IBTR of 56 months (13-124 months), 73.6% of patients
were alive. Second IBTR rate was 11.3%. Distant
metastases rate was 2.6%. Three patients died of distant
disease progression (2.6%). Contralateral breast cancer
occurred in 2.6% of cases, while 0.9% developed second
new primaries in distant sites.
Conclusion
The study population included patients from 8 institutions
who had resectable IBTR and either refused salvage
mastectomy or were offered the second BCS, including
PBI, as a valid alternative. Local control obtained with
IORT was comparable to that previously described in
literature, which ranges between 7% and 32%, with a mean
value of about 10%. Multivariate analysis to identify
prognostic factors for a better selection of patients is
ongoing.
PO-0662 Target therapy and hypofractionated whole
breast radiotherapy: an unexpected protective factor.
M.C. De Santis1, F. Di Salvo2, F. Bonfantini3, S. Di
Cosimo4, E.D. Mantero1, V. Riboldi1, M. Dispinzieri1, F.
Soncini1, V. Cosentino3, G. Bianchi4, M. Gennaro5, M.
Sant2, R. Valdagni6, E. Pignoli 3, L. Lozza1
1Fondazione IRCCS Istituto Nazionale dei Tumori,
Radiotherapy Department, Milan, Italy
2Fondazione IRCCS Istituto Nazionale dei Tumori,
Analytic Epidemiology and Health Impact Unit, Milan,
Italy
3Fondazione IRCCS Istituto Nazionale dei Tumori, Medical
Physics Unit, Milan, Italy
4Fondazione IRCCS Istituto Nazionale dei Tumori,
Oncology Department, Milan, Italy
5Fondazione IRCCS Istituto Nazionale dei Tumori, Breast
Surgery Unit, Milan, Italy
6Fondazione IRCCS Istituto Nazionale dei Tumori,