ESTRO 36 Abstract Book

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S92 ESTRO 36
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derived DPs from treatment planning. In addition, the
maximal dose to the skin was determined. QC of EMT-
based dose distributions were normalized to the
corresponding values from treatment planning, so the
relative changes are reported.
Results
Without simulated errors, the maxim um dosimetric
deviations to the treatment plan were found on the 2 nd
treatment day in median -6.2% for the DNR and -4.3% for
the CI of the PTV.
For error simulation, 15,107 pairwise swaps of catheters
were analyzed. The reconstructed dose distributions
resulted in DNR changes form -22.7% to 38.9% (mean:
0.6%, SD: 5.5%) and CI changes from -63.5% to 11.4%
(mean: -7.4%, SD: 7.8%).
For each shift of single catheters, 2,264 combinations of
dose distributions were calculated. Relative dosimetric
changes for DNR ranged from -4.1% to 3.5%, from -6.8% to
6.2% and from -8.8% to 8.1% for catheter shifts of 5, 10
and 15 mm, respectively at mean values between 0.0% and
-0.3%. The CI for the PTV showed a mean change of -0.3%,
-1.3% and -2.8%, respectively. Increased catheter shifts
correlated with a higher local dose at the skin (see
figures). In addition, each 3D dose distribution was
analyzed to identify individual local dose deviations.
Conclusion
Statistically, the maximum dose deviation was found on
the 2nd day, what might impact boost treatments with two
fractions only. Based on EMT-determined dose
calculations adaptive treatment protocols and tests for
possible treatment delivery errors should be
implemented. Further work is required for the registration
method.
OC-0180 Prospective study of APBI With Multicatheter
Brachytherapy in Local Relapses of Breast Cancer
E. Villafranca Iturre1 , L. Rubi2, M. Barrado 1, A. Sola1, P.
Navarrete1, A. Manterola1, M. Dominguez1, G. Asin1, M.
Campo 1, I. Visus1, G. Martinez1
1 Hospital of Navarra, Radiation Oncology, Pamplona,
Spain
2 Hospital Juan Ramon Jimenez, Radiation Oncology,
Huelva, Spain
Purpose or Objective
To examine 5-year rates of local control for breast cancer
patients with local relapses after second conservative
surgery and accelerated partial breast irradiation (APBI).
Material and Methods
Eligibility included local relapses of breast cancer <3 cm
in size after lumpectomy with negative surgical margins.
The APBI dose delivered was 34 Gy in 10 twice-daily
fractions over 5 days for high-dose-rate. This analysis
focuses on ipsilateral breast recurrence(LBR), regional
recurrence (RR), and distant metastases (DM), disease-
free and overall survival.
Results
The median follow-up was 49.6 months (5-98m). Fithty
two patients (p) were accrued from Sep 2008 to August
2015.
Histology: Intraductal carcinoma 15 p, Ductal carcinoma
31 p, Lobulillar carcinoma: 5 p; Papilar carcinoma : 1p; 50
p had T1 tumors and 2 p had T2. Seventy-five percent were
estrogen receptor and/or progesterone receptor positive.
There have been 4 local breast recurrences, 1 regional
recurrence (RR), and 1 distant metastases (DM), The 5-
year Local Recurrence Disease Free rate was 91.6%. The
5-year Disease Free Survival and Overall Survival rates are
87 % and 100%, respectively.
Conclusion
This prospective trial studying APBI in local relapses of
Breast Cancer show a high local control, so this treatment
is an real option to Mastectomy in these patients
OC-0181 Long-term clinical and cosmetic outcomes of
high-dose-rate brachytherapy for early breast cancer
F. Arcidiacono1, L. Chirico1, M. Italiani1, P. Anselmo 1, M.
Casale1, L. Draghini1, F. Trippa1, S. Fabiani1, M. Basagni1,
E. Maranzano1
1"S.Maria" Hospital, Radiotherapy Oncology Centre,
Terni, Italy
Purpose or Objective
To report long-term clinical and cosmetic outcomes of
partial breast irradiation (PBI) with 192Ir high-dose-rate
brachytherapy (HDR-BRT) in early breast cancer patients.
Material and Methods
From May 2005 to February 2012, 124 patients undergoing
conservative surgery for early breast cancer were
recruited in a phase II trial of exclusive 192Ir HDR-BRT.
Inclusion criteria were: age >40, PS 0-2, unifocal invasive
ductal cancer, intraductal cancer component <25%,
negative axillary nodes and tumor size ≤2.5 cm. Treatment
schedule was 4 Gy twice a day for 4-5 days, up to a total
dose of 32 Gy in 8 fractions with a minimum interval
between daily fractions of at least 6 hours. Late toxicity
was graded at each follow-up visit according to
RTOG/EORTC scoring criteria and cosmetic outcomes
according to Harvard criteria and scored as excellent,
good, fair and poor.
Results
Median age was 67 years (range, 42-85). There were 10
(8%) pT1a, 38 (31%) pT1b, 68 (55%) pT1c and 8 (6%) pT2.
Estrogenic and progestinic receptors were positive in 113
(91%) and 104 (85%) cases, respectively. 110 (88%) and 15
(12%) patients received adjuvant hormonal therapy and
chemotherapy, respectively. Median follow-up was 77
months (range, 8-132). 1 (0,8%) isolated out-field breast
relapse occurred 109 months after HDR-BRT. 1 (0,8%)
patient developed contralateral breast cancer
and another one (0,8%) regional relapse in axillary node.
13 (10,5%) patients reported a second primary cancer. 5-
and 10-year overall survival and cancer specific free
survival were 95% and 88%, 100% and 98%,
respectively. At last follow-up, 114 (92%) patients were
alive without disease and 3 (2,5%) with systemic disease.
10 (8%) patients died: 1 (0,8%) for breast cancer, 2 (1,6%)
for other cancers and 7 (5%) for other causes. Cosmetic
outcomes were excellent in 102 (82%), good in 11 (9%), fair