- Email: [email protected]
EP-1237: SIB in breast conserving therapy using presegmentation modulated radiotherapy (OAPS) : A dosimetric study
ESTRO 33, 2014 over 95% homogeneous target coverage VMAT Dmax 120.5 (range 111140.7) and IMRT Dmax 108.1 (range 117.1- 102.2). Normal tissue constrains were defined and kept as: lung (V20Gy<30%, V5Gy<60%-70%), heart (V10 Gy<50%, V35Gy<10%). Acute toxicity was very mild (only grade 1-2 dermitis, asthenia and dysphagia). Correct cosmetic out-come in median of 9.6 (range 3.9-19.1) months was observed. Conclusions: The value of IMRT still stands in more complex breast planning and results in better homogeneity and less dose exposure to lungs and heart, reducing side effects and conserving good cosmetic outcome after breast conservative surgery. Planning is time-consuming and a designed IMRT template is useful, including strict constraints and creation of central avoiding structures around the heart. Time and costs of complex planning are largely compensated by gain in quality of life and reduced overall treatment times (15 fractions only). EP-1235 Prognostic factor and failure pattern differences between invasive micropapillary carcinoma and IDC of the breast J.I. Yu1, D.H. Choi1, S.J. Huh1, W. Park1, I.A. Kim2, J.H. Kim3, K.H. Shin4, Y.B. Kim5 1 Samsung Medical Center, Radiation Oncology, Korea Seoul, Korea Republic of 2 Seoul National University Bundang Hospital, Radiation Oncology, Korea Seongnam, Korea Republic of 3 Dongsan Medical Center, Radiation Oncology, Korea Daegu, Korea Republic of 4 National Cancer Center, Radiation Oncology, Korea Goyang, Korea Republic of 5 Yonsei University College of Medicine, Radiation Oncology, Korea Seoul, Korea Republic of
S67 Purpose/Objective: Safetac-based soft silicone dressings protect fragile radiation-damaged skin from additional mechanical damage caused by friction against clothing or other body parts. We previously showed that Mepilex Lite dressings, when used in a management setting, decrease the severity of radiation-induced acute skin reactions but do not affect moist desquamation rates. Here we investigate the prophylactic use of another Safetac product, Mepitel Film, on skin reaction severity and in particular, moist desquamation rates. Materials and Methods: A total of 80 breast cancer patients receiving radiation therapy were recruited between October 2012 and May 2013 in Dunedin Hospital, New Zealand; 78 participants contributed data for analysis. Lateral and medial halves of the chest wall or breast to be irradiated were randomized to Mepitel Film or aqueous cream; skin dose was measured using thermoluminescent dosimeters; skin reaction severity was assessed using the radiation induced skin reaction assessment scale (RISRAS) and the RTOG scale. Results: Overall skin reaction severity was reduced by 92%(p<0.0001) in favour of Mepitel Film (RISRAS). All patients developed some form of reaction in cream-treated skin which progressed to moist desquamationin 26% of patients (RTOG grades I: 28%; IIA: 46%; IIB: 18%; III: 8%). Only 44% of patients had a skin reaction under the Film which did not progress to moist desquamation in any of the patients (RTOG grades I: 36%; IIA: 8%). Conclusions: Mepitel Film completely prevented moist desquamation and reduced skin reaction severity by 92%, when used prophylactically in our cohort.
Purpose/Objective: We designed the present study to investigate the differences of prognostic factor and failure pattern between invasive micropapillary carcinoma (IMPC) and randomly matched invasive ductal carcinoma (IDC) of the breast from multi-institutions of the Korean Radiation Oncology Group (KROG). Materials and Methods: This retrospective study was performed in IMPC and randomly matched IDC patients treated at eight institutions of the Korean Radiation Oncology Group from January 1999 to November 2011. Eligibility of this study was curatively resected female breast cancer with pathologic IMPC subtype, without neoadjuvant chemotherapy. If patient had only in situ carcinoma, or distant metastasis confirmed before surgery, was excluded. Exact matches with pathologic IDC subtype were made by age (± 3 years), pathologic stage (T and N), treatment methods [Surgery ± radiation therapy (RT)] and date of surgery (± 6 months) in the same institution. To analyse patterns of failure, first site of recurrence was used, and if two or more site recurrences developed in a month, categorized simultaneous recurrence. Loco-regional recurrence (LRR) was defined as the appearance of tumors in the ipsilateral breast and/or chest wall, axilla, internal mammary, infraclavicular or supraclavicular area. Results: Total 246 patients from the two KROG institutions were analyzed. The median follow-up period was 60.7 months (range, 5.5 to 134.2 months) for IMPC and 63 months (range, 10.5 to 163.0 months). In the comparison of pathologic characteristics, lympho-vascular invasion was significantly higher in IMPC patients (68.8% vs 41.1%, P<0.0001). During the follow-up period, recurrences developed in 21 of IMPC patients (17.1 %) and 10 of IDC patients (8.1%), and LRR developed in 16 of IMPC patients (13.0%) and three of IDC patients (2.4%). Among them, 12 of IMPC patients (9.8%) and one of IDC patients (0.8%) showed LRR only. Distant metastasis rate was not different between two groups (P=1.000) LRR-free survival were different significantly between two groups (P=0.001). Although statistical significance was not reached (P=0.077), IDC showed tendency of higher distant metastasis-free survival difference. It is because distant metastasis consequently appeared in LRR patients after median 38 months (range, 1 to 58 months). Conclusions: IMPC is associated with higher rate of lymph-vascular invasion, and LRR propensity compared with randomly exact matched IDC. Modification of loco-regional modality might be needed in this pathologic subtype of breast cancer. EP-1236 Mepitel Film prevents radiation-induced moist desquamation P. Herst1, N.C. Bennett2, A. Sutherland2, R.I. Peszynski2, D.B. Paterson1, M.L. Jasperse1 1 University of Otago, Radiation Therapy, Wellington, New Zealand 2 Southern Blood and Cancer Centre, Radiation Oncology, Dunedin, New Zealand
EP-1237 SIB in breast conserving therapy using presegmentation modulated radiotherapy (OAPS) : A dosimetric study I. Barillot1, J. Blanchecotte1, A. Ruffier-Loubiere1, G. Bernadou1, A. Reynaud-Bougnoux1, C. Bramoulle1 1 Hôpital Bretonneau, Radiotherapy, Tours, France Purpose/Objective: Since May 2011, OAPS (DosisoftTM), that demonstrates dosimetric benefits compared to 3D conformal technique (3D-RT), is routinely used in the radiotherapy department of the University Hospital of Tours for delivering the whole breast irradiation (WBI) after breast conserving surgery. The boost dose remains administrated with 3D-RT (photons or electrons beams) after WBI. 3DRT-SIB has been investigated and showed excellent results in literature. Inverse optimization intensity modulated SIB was also developed in the Young Boost trial. The aim of this study is to assess the potential dosimetric gain of the OAPS-SIB technique in comparison to the current WBI OAPS+3D-RT boost. Materials and Methods: The dosimetric data of the first 50 patients, who received 50 Gy in 25 fractions WBI using OAPS technique followed by 16 Gy boost delivered with 3D-RT, have been selected in this study (Tech1). For each patient, a new treatment plan has been generated using a mono-isocentric OAPS-SIB technique for delivering 50.4 Gy/1.8Gy/fraction to the PTVBreast-boost and 63 Gy/2.25Gy/fraction to
S68 the PTVboost in 28 fractions (Tech2). The dose distributions were compared in EQD2Gy using meanDose, D2%, D5%, D98%, D95%, homogeneity index (HI) for target volumes and meandose for the heart and the lung. Results: The meanDose to the PTVbreast-boost was significantly lower in Tech2 than in Tech1 (53,45 Gy vs 51 Gy) whereas D98% and D95% were comparable in the 2 techniques. The D2% and D5% were also lower of about 10% in Tech2 (p<0,000001) leading to a better HI of 1.22+/-0.03 vs 1.35+/-0.07. By contrast, the meanDose to the PTVboost was slightly but significantly higher (67.85 Gy vs 66.39 Gy p<0,000007) in Tech2, and the highest doses were increased by 3% (p<0.00001). The meanDoses to the heart were similar and we observed a relative decrease of 14% of the lung MeanDose (p<0,00001). Conclusions: The OAPS-SIB technique results in a better homogeneity of the dose distribution to the breast at the price of slight increase of the highest doses delivered to the tumor bed. It also offers a better lung sparing. The treatment delivery will be simplified with the monoisocentic setup. A clinical validation is now warranted. EP-1238 Hypofractionated whole-breast radiotherapy in Italy: A survey by the Breast Cancer Study Group of AIRO C. Vidali1, A.I.R.O. Breast Cancer Study Group2, F. Giudici3 1 Ospedale Maggiore, Radiotherapy, Trieste, Italy 2 Italian Society of Radiation Oncology, Via Farini 62, Rome, Italy 3 University of Trieste, Medical Surgical and Health Department, Trieste, Italy Purpose/Objective: In the last two decades a growing interest in the use of hypofractionated whole-breast radiotherapy (RT) for women with early breast cancer has been observed. In the Breast Cancer Study Group of AIRO (Italian Society of Radiation Oncology) a survey has been carried on in the year 2013 (from the beginning of January to the end of September) to assess the use and the characteristics of hypofractionated regimens in Italy. Materials and Methods: A short questionnaire was sent to all Italian Radiotherapy Centers. First of all, it was asked to report if hypofractionated RT was applied. The other items investigated: the possibility of selection criteria, such as patient’ age and tumour hystology; the schedule adopted (total dose, dose/fraction, number of fractions/week), the use of concomitant or sequential boost and its schedule. The data were compared with those collected in a previous survey, carried on in the years 2009-2010 in the Italian Radiotherapy Centers. Results: The questionnaire was completed by 132 Centers over 175, representing a large and significant proportion of the Italian Radiotherapy Centers. Hypofractionated RT is applied in 100 Centers (75.8%) and more than one regimen is used in some of them (overall 107 forms were collected). In 40 out of 107 forms (37.4%), age is not used as a selection criteria, in 5 (4.7%) it is not indicated, while in 62 (57.9%) different age cut-offs are specified (from 40 to 75 years). In 56 treatment regimens (52%) all hystological types are treated; in 36 (34%) only invasive cancers; in 11 (10%) only invasive ductal carcinomas. Total dose ranges from 28.5 to 50 Gy; dose per fraction varies from 2.25 to 5.70 Gy and the number of fractions varies between 5 and 22. The majority of the hypofractionated RT regimens include the boost (80/107), which is delivered sistematically in 61 of them (57%) and only according to specific criteria (age, margin status) in 14 of them (13.1%). Boost dose and fractionation show a wide range (from 0.25 Gy in case of concomitant boost up to 10 Gy for IORT). In the previous Italian survey (years: 2009-2010), only 33 Centers completed the questionnaire and 28 of them (84.8%) applied whole breast hypofractionation. The dose per fraction range is wider in the current survey (2.25 – 5.70 Gy vs. 2.25 – 3.40 Gy), indicating a trend toward dose escalation. Furthermore, more Centers now use the boost on the tumour bed in comparison with the previous study (74.8% vs. 60.7%). Conclusions: This survey is representative of the Italian radiation oncology reality and of the regional distribution and points out that whole breast hypofractionated RT is becoming more and more widespread in Italy. Apart from less protracted schedules being more convenient for patients, such a reduction in the number of fractions in a large group of cases, represents an advantage for Health Service and society, by decreasing the pressure on machine time and human resources, especially if they are limited.
ESTRO 33, 2014 EP-1239 Effectiveness and toxicity of IORT during breast conserving surgery followed by adjuvant whole breast radiotherapy B. Urbanski1, A. Roszak1, S. Adamczyk2, M. Litoborski3 1 Greater Poland Cancer Centre, Radiotherapy and Gynaecological Oncology, Poznan, Poland 2 Greater Poland Cancer Centre, Department of Medical Physics, Poznan, Poland 3 Candela, Candela, Poznan, Poland Purpose/Objective: The aim of the study was to report four years of a single-centre experience of intraoperative radiotherapy (IORT) during breast-conserving surgery (BCS) as a tumor bed boost using high energy electrons and to evaluate effectiveness of treatment, analyze early and late radiation reactions, cosmetic effect and quality of life. Materials and Methods: Between 2008 and 2011 in 150 breast cancers patients treated in our centre intraoperative radiotherapy as a tumor bed boost was applied using mobile electron accelerator Mobetron 1000 (IntraOp Medical, Inc.). IORT boost (10 Gy) was followed by 50 Gy wholebreast external beam radiotherapy (EBRT). Chemotherapy, if indicated, was given before EBRT. The minimal observation period was at least 1 year. The physical data analysis was based on larger group of 255 patients treated between May 2008 and November 2012. Clinical outcomes was assessed by physical examination, photos of the breast, questionnaires (QLQ-C30 and QLQ-BR23), analysis of acute and late toxicity, mammography with ultrasounds. Results: There was no local recurrences. Acute skin reactions in grade 1 and 2 were observed in 21,2% of pts, with no acute and late toxicities in grade 3 and 4. The cosmetic outcome was good to excellent in 81,5% of pts. Pain in breast was observed in 20,6 % pts, hyperesthesia of the skin in 17,0 % pts. The edema of breast was reported by 81,3 % of pts after 1 month, 63,4% after 6 months, 54,9 % after 1 year and 56% after 2 years from end of RT. The colour of breast skin has changed in 67,8 % of pts after 1 month, 44,1 % after 6 months, 37,8 % after 1 year, 31% after 2 years from the end of RT. Patients were treated using all available electron beam energies: 6 MeV energy was used in 52% cases but also 9 MeV, 4 MeV and 12 MeV (33%, 13% and 2% cases respectively) were used. In 51% cases applicator size was 5 cm in diameter. The smallest was 4 cm (27%) and the largest 7 cm (used only in 1% cases). Treatment applicators with 0°, 15° and 30° beveled tips were used (33%, 31% and 36% cases respectively). In 56% cases no bolus was needed; 0.5 cm bolus was used in 83 cases (33%). In all treatment procedures aluminium-lead shielding plates were used, 82% of which were 0.5 cm thick. The thickness of irradiated breast gland was less than 1.5 cm in exactly half of pts, between 1.5 cm and 2 cm in 40%. Breast gland thicker than 2.5 cm was irradiated rather rarely – only 3% of all treated cases. PTV volume (volume of tissue encompassed by the 90% isodose line) was rather small, with average volume of 35.31 cc ranging from 12.00 cc to 75.35 cc. Conclusions: Intraoperative radiotherapy is proved to be effective, tolerable and perspective treatment procedure. The external beam course afterwards was shortened by 1 week. EP-1240 Arm and shoulder morbidity following surgery and radiotherapy of breast cancer S. Johansen1 1 DNR - Norwegian Radium Hospital, Radiotherapy, Oslo, Norway Purpose/Objective: To explore the relationship between radiotherapy dose levels estimated in the shoulder region and arm/shoulder symptoms in breast cancer (BC) survivors. Materials and Methods: This study included 183 BC patients who had received 4 field radiotherapy combined with or without chemotherapy and/or hormone treatment during 1998-2002. Individual radiotherapy dose data, reflected by dose volume histograms (DVHs) for the shoulder joint and joining structures, were obtained from the achieved CT-based treatment plans. Individual median, mean and maximum shoulder doses were extracted. Arm/shoulder morbidity was assessed 29-58 months after therapy, and included flexion, abduction, stiffness, pain, use of arm, swollen arm, numbness, lymphedema and fibrosis. The relationship between shoulder dose and clinical endpoints was assessed by Spearman’s correlation and multivariate logistic regression. Results: Ninety one percent of the included patients had some degree of shoulder/arm symptoms. Neither mean nor maximum dose was associated with arm/shoulder clinical endpoints. However, significant
S67 Purpose/Objective: Safetac-based soft silicone dressings protect fragile radiation-damaged skin from additional mechanical damage caused by friction against clothing or other body parts. We previously showed that Mepilex Lite dressings, when used in a management setting, decrease the severity of radiation-induced acute skin reactions but do not affect moist desquamation rates. Here we investigate the prophylactic use of another Safetac product, Mepitel Film, on skin reaction severity and in particular, moist desquamation rates. Materials and Methods: A total of 80 breast cancer patients receiving radiation therapy were recruited between October 2012 and May 2013 in Dunedin Hospital, New Zealand; 78 participants contributed data for analysis. Lateral and medial halves of the chest wall or breast to be irradiated were randomized to Mepitel Film or aqueous cream; skin dose was measured using thermoluminescent dosimeters; skin reaction severity was assessed using the radiation induced skin reaction assessment scale (RISRAS) and the RTOG scale. Results: Overall skin reaction severity was reduced by 92%(p<0.0001) in favour of Mepitel Film (RISRAS). All patients developed some form of reaction in cream-treated skin which progressed to moist desquamationin 26% of patients (RTOG grades I: 28%; IIA: 46%; IIB: 18%; III: 8%). Only 44% of patients had a skin reaction under the Film which did not progress to moist desquamation in any of the patients (RTOG grades I: 36%; IIA: 8%). Conclusions: Mepitel Film completely prevented moist desquamation and reduced skin reaction severity by 92%, when used prophylactically in our cohort.
Purpose/Objective: We designed the present study to investigate the differences of prognostic factor and failure pattern between invasive micropapillary carcinoma (IMPC) and randomly matched invasive ductal carcinoma (IDC) of the breast from multi-institutions of the Korean Radiation Oncology Group (KROG). Materials and Methods: This retrospective study was performed in IMPC and randomly matched IDC patients treated at eight institutions of the Korean Radiation Oncology Group from January 1999 to November 2011. Eligibility of this study was curatively resected female breast cancer with pathologic IMPC subtype, without neoadjuvant chemotherapy. If patient had only in situ carcinoma, or distant metastasis confirmed before surgery, was excluded. Exact matches with pathologic IDC subtype were made by age (± 3 years), pathologic stage (T and N), treatment methods [Surgery ± radiation therapy (RT)] and date of surgery (± 6 months) in the same institution. To analyse patterns of failure, first site of recurrence was used, and if two or more site recurrences developed in a month, categorized simultaneous recurrence. Loco-regional recurrence (LRR) was defined as the appearance of tumors in the ipsilateral breast and/or chest wall, axilla, internal mammary, infraclavicular or supraclavicular area. Results: Total 246 patients from the two KROG institutions were analyzed. The median follow-up period was 60.7 months (range, 5.5 to 134.2 months) for IMPC and 63 months (range, 10.5 to 163.0 months). In the comparison of pathologic characteristics, lympho-vascular invasion was significantly higher in IMPC patients (68.8% vs 41.1%, P<0.0001). During the follow-up period, recurrences developed in 21 of IMPC patients (17.1 %) and 10 of IDC patients (8.1%), and LRR developed in 16 of IMPC patients (13.0%) and three of IDC patients (2.4%). Among them, 12 of IMPC patients (9.8%) and one of IDC patients (0.8%) showed LRR only. Distant metastasis rate was not different between two groups (P=1.000) LRR-free survival were different significantly between two groups (P=0.001). Although statistical significance was not reached (P=0.077), IDC showed tendency of higher distant metastasis-free survival difference. It is because distant metastasis consequently appeared in LRR patients after median 38 months (range, 1 to 58 months). Conclusions: IMPC is associated with higher rate of lymph-vascular invasion, and LRR propensity compared with randomly exact matched IDC. Modification of loco-regional modality might be needed in this pathologic subtype of breast cancer. EP-1236 Mepitel Film prevents radiation-induced moist desquamation P. Herst1, N.C. Bennett2, A. Sutherland2, R.I. Peszynski2, D.B. Paterson1, M.L. Jasperse1 1 University of Otago, Radiation Therapy, Wellington, New Zealand 2 Southern Blood and Cancer Centre, Radiation Oncology, Dunedin, New Zealand
EP-1237 SIB in breast conserving therapy using presegmentation modulated radiotherapy (OAPS) : A dosimetric study I. Barillot1, J. Blanchecotte1, A. Ruffier-Loubiere1, G. Bernadou1, A. Reynaud-Bougnoux1, C. Bramoulle1 1 Hôpital Bretonneau, Radiotherapy, Tours, France Purpose/Objective: Since May 2011, OAPS (DosisoftTM), that demonstrates dosimetric benefits compared to 3D conformal technique (3D-RT), is routinely used in the radiotherapy department of the University Hospital of Tours for delivering the whole breast irradiation (WBI) after breast conserving surgery. The boost dose remains administrated with 3D-RT (photons or electrons beams) after WBI. 3DRT-SIB has been investigated and showed excellent results in literature. Inverse optimization intensity modulated SIB was also developed in the Young Boost trial. The aim of this study is to assess the potential dosimetric gain of the OAPS-SIB technique in comparison to the current WBI OAPS+3D-RT boost. Materials and Methods: The dosimetric data of the first 50 patients, who received 50 Gy in 25 fractions WBI using OAPS technique followed by 16 Gy boost delivered with 3D-RT, have been selected in this study (Tech1). For each patient, a new treatment plan has been generated using a mono-isocentric OAPS-SIB technique for delivering 50.4 Gy/1.8Gy/fraction to the PTVBreast-boost and 63 Gy/2.25Gy/fraction to
S68 the PTVboost in 28 fractions (Tech2). The dose distributions were compared in EQD2Gy using meanDose, D2%, D5%, D98%, D95%, homogeneity index (HI) for target volumes and meandose for the heart and the lung. Results: The meanDose to the PTVbreast-boost was significantly lower in Tech2 than in Tech1 (53,45 Gy vs 51 Gy) whereas D98% and D95% were comparable in the 2 techniques. The D2% and D5% were also lower of about 10% in Tech2 (p<0,000001) leading to a better HI of 1.22+/-0.03 vs 1.35+/-0.07. By contrast, the meanDose to the PTVboost was slightly but significantly higher (67.85 Gy vs 66.39 Gy p<0,000007) in Tech2, and the highest doses were increased by 3% (p<0.00001). The meanDoses to the heart were similar and we observed a relative decrease of 14% of the lung MeanDose (p<0,00001). Conclusions: The OAPS-SIB technique results in a better homogeneity of the dose distribution to the breast at the price of slight increase of the highest doses delivered to the tumor bed. It also offers a better lung sparing. The treatment delivery will be simplified with the monoisocentic setup. A clinical validation is now warranted. EP-1238 Hypofractionated whole-breast radiotherapy in Italy: A survey by the Breast Cancer Study Group of AIRO C. Vidali1, A.I.R.O. Breast Cancer Study Group2, F. Giudici3 1 Ospedale Maggiore, Radiotherapy, Trieste, Italy 2 Italian Society of Radiation Oncology, Via Farini 62, Rome, Italy 3 University of Trieste, Medical Surgical and Health Department, Trieste, Italy Purpose/Objective: In the last two decades a growing interest in the use of hypofractionated whole-breast radiotherapy (RT) for women with early breast cancer has been observed. In the Breast Cancer Study Group of AIRO (Italian Society of Radiation Oncology) a survey has been carried on in the year 2013 (from the beginning of January to the end of September) to assess the use and the characteristics of hypofractionated regimens in Italy. Materials and Methods: A short questionnaire was sent to all Italian Radiotherapy Centers. First of all, it was asked to report if hypofractionated RT was applied. The other items investigated: the possibility of selection criteria, such as patient’ age and tumour hystology; the schedule adopted (total dose, dose/fraction, number of fractions/week), the use of concomitant or sequential boost and its schedule. The data were compared with those collected in a previous survey, carried on in the years 2009-2010 in the Italian Radiotherapy Centers. Results: The questionnaire was completed by 132 Centers over 175, representing a large and significant proportion of the Italian Radiotherapy Centers. Hypofractionated RT is applied in 100 Centers (75.8%) and more than one regimen is used in some of them (overall 107 forms were collected). In 40 out of 107 forms (37.4%), age is not used as a selection criteria, in 5 (4.7%) it is not indicated, while in 62 (57.9%) different age cut-offs are specified (from 40 to 75 years). In 56 treatment regimens (52%) all hystological types are treated; in 36 (34%) only invasive cancers; in 11 (10%) only invasive ductal carcinomas. Total dose ranges from 28.5 to 50 Gy; dose per fraction varies from 2.25 to 5.70 Gy and the number of fractions varies between 5 and 22. The majority of the hypofractionated RT regimens include the boost (80/107), which is delivered sistematically in 61 of them (57%) and only according to specific criteria (age, margin status) in 14 of them (13.1%). Boost dose and fractionation show a wide range (from 0.25 Gy in case of concomitant boost up to 10 Gy for IORT). In the previous Italian survey (years: 2009-2010), only 33 Centers completed the questionnaire and 28 of them (84.8%) applied whole breast hypofractionation. The dose per fraction range is wider in the current survey (2.25 – 5.70 Gy vs. 2.25 – 3.40 Gy), indicating a trend toward dose escalation. Furthermore, more Centers now use the boost on the tumour bed in comparison with the previous study (74.8% vs. 60.7%). Conclusions: This survey is representative of the Italian radiation oncology reality and of the regional distribution and points out that whole breast hypofractionated RT is becoming more and more widespread in Italy. Apart from less protracted schedules being more convenient for patients, such a reduction in the number of fractions in a large group of cases, represents an advantage for Health Service and society, by decreasing the pressure on machine time and human resources, especially if they are limited.
ESTRO 33, 2014 EP-1239 Effectiveness and toxicity of IORT during breast conserving surgery followed by adjuvant whole breast radiotherapy B. Urbanski1, A. Roszak1, S. Adamczyk2, M. Litoborski3 1 Greater Poland Cancer Centre, Radiotherapy and Gynaecological Oncology, Poznan, Poland 2 Greater Poland Cancer Centre, Department of Medical Physics, Poznan, Poland 3 Candela, Candela, Poznan, Poland Purpose/Objective: The aim of the study was to report four years of a single-centre experience of intraoperative radiotherapy (IORT) during breast-conserving surgery (BCS) as a tumor bed boost using high energy electrons and to evaluate effectiveness of treatment, analyze early and late radiation reactions, cosmetic effect and quality of life. Materials and Methods: Between 2008 and 2011 in 150 breast cancers patients treated in our centre intraoperative radiotherapy as a tumor bed boost was applied using mobile electron accelerator Mobetron 1000 (IntraOp Medical, Inc.). IORT boost (10 Gy) was followed by 50 Gy wholebreast external beam radiotherapy (EBRT). Chemotherapy, if indicated, was given before EBRT. The minimal observation period was at least 1 year. The physical data analysis was based on larger group of 255 patients treated between May 2008 and November 2012. Clinical outcomes was assessed by physical examination, photos of the breast, questionnaires (QLQ-C30 and QLQ-BR23), analysis of acute and late toxicity, mammography with ultrasounds. Results: There was no local recurrences. Acute skin reactions in grade 1 and 2 were observed in 21,2% of pts, with no acute and late toxicities in grade 3 and 4. The cosmetic outcome was good to excellent in 81,5% of pts. Pain in breast was observed in 20,6 % pts, hyperesthesia of the skin in 17,0 % pts. The edema of breast was reported by 81,3 % of pts after 1 month, 63,4% after 6 months, 54,9 % after 1 year and 56% after 2 years from end of RT. The colour of breast skin has changed in 67,8 % of pts after 1 month, 44,1 % after 6 months, 37,8 % after 1 year, 31% after 2 years from the end of RT. Patients were treated using all available electron beam energies: 6 MeV energy was used in 52% cases but also 9 MeV, 4 MeV and 12 MeV (33%, 13% and 2% cases respectively) were used. In 51% cases applicator size was 5 cm in diameter. The smallest was 4 cm (27%) and the largest 7 cm (used only in 1% cases). Treatment applicators with 0°, 15° and 30° beveled tips were used (33%, 31% and 36% cases respectively). In 56% cases no bolus was needed; 0.5 cm bolus was used in 83 cases (33%). In all treatment procedures aluminium-lead shielding plates were used, 82% of which were 0.5 cm thick. The thickness of irradiated breast gland was less than 1.5 cm in exactly half of pts, between 1.5 cm and 2 cm in 40%. Breast gland thicker than 2.5 cm was irradiated rather rarely – only 3% of all treated cases. PTV volume (volume of tissue encompassed by the 90% isodose line) was rather small, with average volume of 35.31 cc ranging from 12.00 cc to 75.35 cc. Conclusions: Intraoperative radiotherapy is proved to be effective, tolerable and perspective treatment procedure. The external beam course afterwards was shortened by 1 week. EP-1240 Arm and shoulder morbidity following surgery and radiotherapy of breast cancer S. Johansen1 1 DNR - Norwegian Radium Hospital, Radiotherapy, Oslo, Norway Purpose/Objective: To explore the relationship between radiotherapy dose levels estimated in the shoulder region and arm/shoulder symptoms in breast cancer (BC) survivors. Materials and Methods: This study included 183 BC patients who had received 4 field radiotherapy combined with or without chemotherapy and/or hormone treatment during 1998-2002. Individual radiotherapy dose data, reflected by dose volume histograms (DVHs) for the shoulder joint and joining structures, were obtained from the achieved CT-based treatment plans. Individual median, mean and maximum shoulder doses were extracted. Arm/shoulder morbidity was assessed 29-58 months after therapy, and included flexion, abduction, stiffness, pain, use of arm, swollen arm, numbness, lymphedema and fibrosis. The relationship between shoulder dose and clinical endpoints was assessed by Spearman’s correlation and multivariate logistic regression. Results: Ninety one percent of the included patients had some degree of shoulder/arm symptoms. Neither mean nor maximum dose was associated with arm/shoulder clinical endpoints. However, significant