ESTRO 36 Abstract Book

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S342 ESTRO 36 2017
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Associate Professor- Department of Oncology and
Hemato-oncology- Director Radiation Oncology 1 and
Prostate Cancer Program, Milan, Italy
Purpose or Objective
To evaluate the impact of trastuzumab on acute skin
toxicity in breast cancer patients treated with
hypofractionated radiotherapy to the whole breast and
chemotherapy with anthracycline and taxane.
Material and Methods
From April 2009 to April 2016, we enrolled 632 patients
who underwent breast conservative surgery followed by
adjuvant hypofractionated whole breast irradiation.
Patients received 42.4 Gy in 16 daily fractions, 2.65 Gy per
fraction. The boost to the tumor bed was administered
only in grade 3 patients and in patients with close or
positive margins (< 1mm). Acute and late toxicity was
prospectively assessed during and after radiotherapy
according to RTOG scale. Multivariable logistic regression
models were applied to evaluate the impact of
trastuzumab on the occurrence of acute skin toxicity
(>=G2).
Results
In all patients enrolled,the mean age was 74 (range 46-91
yrs). Regression adjusted models showed that
chemotherapy (OR= 2.0, p=0.03) and boost administration
(OR=2.2, p<0.01) had a significant impact on acute skin
toxicity (Figure 1).
One hundred and sixty-three patients received
chemotherapy. Fifty one of them (30.7%) underwent also
trastuzumab therapy. In this group, we found that G1 and
G2/G3 acute skin toxicity were 50.4% and 33.9% in
patients received only chemotherapy and 64.7% and 21.6%
in patients who receive it associated with trastuzumab,
respectively. Multivariate analysis showed that patients
receiving trastuzumab had decreased risk of acute skin
toxicity >=G2 (OR=0.04, p=0.03) (Figure 2).
Conclusion
The results of our study demonstrated that chemotherapy
impact on acute toxicity in patients undergoing
hypofractionated whole breast irradiation, probably due
to the recall phenomena. Trastuzumab seems to be a
protective factor on acute skin toxicity.
PO-0663 Early toxicity of 150 patients treated with
hypofractionated breast SIB-RT using advanced
techniques
F. Lakosi1, C. Pirson2, P.V. Nguyen2, P. Berkovic2, S. Ben-
Mustapha2, F. Princen2, S. Cucchiaro2, A. Gulyban2, V.
Baart2, P. Coucke 2
1Kaposvar University, Radiotherapy, Kaposvar, Hungary
2CHU de Liège, Radiotherapy, Liège, Belgium
Purpose or Objective
To report physician-and patient reported early toxicity of
hypofractionated breast simultaneous integrated boost
(SIB) approach with Field-in-Field (breast±nodes) and
Volumetric Modulated Arc Therapy (boost) (FiF+VMAT)
after breast-conserving surgery.
Material and Methods
Between November 2013 and July 2016, 150 breast cancer
patients with 154 lesions (T1-2, N0-1, M0) were treated
with adjuvant radiotherapy using VMAT breast SIB
technique. For whole breast irradiation two tangential
field-in-field beams were used, while for SIB a full/half
arc VMAT between the two tangents were applied. Doses
to whole breast and tumor bed were 40.05/45.57 Gy and
48/55.86 Gy respectively, delivered in 15/21 fractions
depending whether elective nodal irradiation (n=41) was
required. Acute toxicities were scored using the Common
Toxicity Criteria for Adverse Events (CTCAEvs4).
Desquamation was scored as: 0- none; 1- dry and 2- moist.
Toxicity was also evaluated with BCTOS and Treatment
related symptoms questionnaires. For analysis
radiotherapy-related cosmetic and breast specific pain
items were selected. Data were recorded baseline, during,
6 weeks and 1 year after treatment.
Results
The median follow-up was 20 months (range:3-36) and 105
patients remained evaluable at 1 year. The maximum
acute toxicities (%) during treatment were the followings:
(G0/G1/G2/≥G3): Dermatitis: 8/79/13/-, Desquamation:
69/27/4/-, Pruritus 49/47/4/-, Oedema: 34/59/7/- and
Pain: 45/48/7/-, Oesophagitis: 83/16/1-. There were no
Grade 3 physician reported acute toxicities. A remarkable
incline in Treatment related symptom scores was observed
during SIB, which improved thereafter in almost all items,
but remained superior to baseline status at 1 year follow
up (Figure). The evolution of BCTOS scores showed the
same pattern (Table).