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EP-0988 COMPARISON OF TWO RADIATION BOOST TECHNIQUES IN PATIENTS UNDERGOING NEOADJUVANT TREATMENT FOR BREAST CANCER
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Conclusions: Despite cobalt machine limitations, Co-f-IMRT technique can replace the use of filters to optimize the dose distribution. EP-0988 COMPARISON OF TWO RADIATION BOOST TECHNIQUES IN PATIENTS UNDERGOING NEOADJUVANT TREATMENT FOR BREAST CANCER L. Nardone1, M.C. De Santis1, B. Diletto1, G.R. D'Agostino1, G. Mattiucci1, R. Canna1, D. Terribile2, G. Franceschini2, A. Mulè3, V. Valentini1 1 Catholic University of the Sacred Heart, Radiation Oncology, Rome, Italy 2 Catholic University of the Sacred Heart, Senology, Rome, Italy 3 Catholic University of the Sacred Heart, Pathology, Rome, Italy Purpose/Objective: Although the use of boost irradiation for women undergoing breast conserving therapy is recommended, the standard technique and the definition of the tumor bed volume have not been clearly established. We retrospectively analyzed two different boost planning techniques, comparing an anticipated preoperative boost technique on the tumor, administered with low dose fractionated radiotherapy (LDFRT), and associated with neoadjuvant chemotherapy, with the standard sequential boost technique to the tumor bed, following surgery and standard whole breast radiotherapy, in order to evaluate the differences in terms of accuracy. Materials and Methods: In our study we retrospectively analyzed a group of patients who received an anticipated preoperative boost on the tumor with LDFRT, for a total dose of 10 Gy by photon technique, and associated with neoadjuvant chemotherapy; for comparison purposes the boost was replanned using a standard electron beam technique to the tumour bed of the same patients, after surgery and standard adjuvant whole breast radiotherapy, for a total dose of 10 Gy over five daily fractions of 2 Gy each. The plans were analyzed for dosimetric coverage of the CT-delineated irradiated volume. The minimal dose received by 95% of the target volume (D95), by 90% of the target volume (D90), and geografic miss were evaluated. A geografic miss was defined as any portion of the tumor bed receiving < 50% of the prescribed dose. Results: Fifteen patients, recruited from 2008 to 2011, were evaluated. We observed 5 patients (33%) with stage IIA, 8 patients (53%) with stage IIB and 2 patient (14%) with stage IIIA. Two patients had lobular cancer and 13 ductal cancer. The grading was G3 in 8 patients and G2 in 7 patients. Median age was 55 years (range 37-70). The standard sequential boost technique resulted in inferior target volume coverage compared with the anticipated boost technique, with a median D95 of 69.2% (range 33.7–86), a median D90 of 75.8% (range 46.7–88.5) and a geografic miss in 27% of patients. The results of the anticipated boost technique were significantly better: 96.8 % (range 94.1–97.8) and 96% (range 92.6–96.8) for median D90 and median D95 respectively and no geografic miss was observed. We observed a dose reduction to heart (with left-sided breast irradiation), using the anticipated preoperative boost technique, when analyzed for all dose-volumes parameters, while the dose to ipsilateral lung resulted higher. Conclusions: Our data show that an anticipated preoperative boost using photons-beam technique allows for optimal tumor bed coverage compared with standard sequential boost after whole breast irradiation using electron-beam technique, preventing geographic misses. Moreover normal tissue may receive less radiation dose, possibly reducing sequential side effects. EP-0989 DETECTION OF MULTIFOCAL/MULTYCENTRIC BREAST CANCER IN CANDIDATES FOR PARTIAL BREAST IRRADIATION S.N. Novikov1, S.V. Kanaev1, P.V. Krivorotko2, V.F. Semiglasov2, L.A. Jukova1, E.V. Kostomina3, U.F. Negustorov3 1 Prof. N.N. Petrov Research Institute of Oncology, Radiation Oncology & Nuclear Medicine, St. Petersburg, Russian Federation 2 Prof. N.N. Petrov Research Institute of Oncology, Breast Cancer, St. Petersburg, Russian Federation 3 Prof. N.N. Petrov Research Institute of Oncology, Radiology, St. Petersburg, Russian Federation Purpose/Objective: Early and accurate diagnosis of multifocal/multycentric breast cancer (MF/MC BC) can be of crucial importance for radiotherapy planning in candidates for partial breast irradiation because in patients (pts) with MF/MC BC whole breast irradiation is preferable strategy. Materials and Methods: We performed retrospective analysis of breast scintigraphy (BSc), mammography (MMg) and ultrasound (US)
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data in 108 consecutive primary pts that underwent mastectomy with subsequent routine histological examinations of breast specimens. In histological reports only MC BC was described as separate entity so patients with MF BC were analyzed as an additional group. Results: According to histological reports MC BC was diagnosed in 8 of 108 evaluated pts: 7 of 8 pts had scintigraphic sings of MC BC on planar and additional one - on tomography examination. US was positive for MC BC in only one and MMg in none of this 8 pts. MF BC was detected in 13 pts: in 8 cases only by BSc, in 2 - by BSc and US, in 2 - by MMg and US, in 1 - only by MMG. Unfortunately, histological reports does not permit correct evaluation of this cases. Conclusions: 1. BSc can significantly alter radiotherapy strategy in candidates for partial breast irradiation because 7.4% of this pts has MC BC which is revealed by BSc in 87.5%-100% of cases. 2. MF BC can be diagnosed in additional 12% of primary pts but this data is preliminary and need correct histological verification. EP-0990 ADJUVANT BREAST RADIOTHERAPY USING SIMULTANEOUS INTEGRATED BOOST - CLINICAL AND DOSIMETRIC PERSPECTIVES S. Alford1, C. Hamilton1, G. Prassas2 1 Austin Health, Radiation Oncology, Melbourne, Australia 2 Austin Health, Medical School, Melbourne, Australia Purpose/Objective: To determine the rates of late radiotherapy toxicity and cosmetic outcomes in a group of patients with early stage breast cancer treated with adjuvant radiotherapy (RT) using an simultaneous integrated boost (SIB) technique. To perform a dosimetric comparison between SIB and standard sequential boost techniques. Materials and Methods: Patients with early stage breast cancer (pT12 N0-1) treated with conservative surgery and adjuvant RT using an SIB technique were identified retrospectively from the departmental database. RT consisted of 45Gy in 25 fractions delivered to the whole ipsilateral breast with a simultaneous boost to the tumour bed of 60Gy in 25 fractions using a forward-planned conformal technique. Information was collected and analyzed for demographic data, and prospectively collected toxicity and cosmesis measures. Dosimetric assessment was performed on a subset of patients to compare acceptability of PTV coverage and homogeneity and dose to organs at risk. Results: Fifty-five eligible female patients were treated between 2009 and 2011. The median age was 61 years (range, 31 to 81 years). Median follow-up was 13.3 months. Thirty-two patients received adjuvant chemotherapy, eight received Herceptin and 47 received endocrine therapy. The majority of tumours were T1 (n=31), a small proportion had nodal metastases (n=13), of which more than half were macroscopic (n=9). Assessment of SIB forward planned dosimetry confirmed excellent coverage of whole breast and boost target volumes for both right and left-sided tumours. Doses to organs at risk were not increased compared to standard sequential boost plans. Two patients did not have toxicity or cosmesis data available. Of the remaining patients, 98% had a good or excellent cosmetic result based on both patient and physician assessment. Late toxicities including oedema, pigmentation, telangiectasia, fibrosis, osteonecrosis and pain were graded using CTCAE v3.0 criteria; grade 0, 1 and 2 toxicity was assigned to 52.8%, 43.4% and 3.8% of patients. There was no grade 3 or greater toxicity. One patient developed a second primary breast cancer in the contralateral breast. There were no cases of local recurrence. Conclusions: The use of a conformal SIB technique is proposed as a mode of delivering adjuvant RT in early stage breast cancer. This schedule is convenient for patients given shortened overall treatment time, provides adequate dosimetry and doses to organs at risk and is well tolerated with low rates of late toxicity. EP-0991 MYOCARDIAL PERFUSION DEFECTS FOLLOWING RADIOTHERAPY FOR BREAST CANCER DETECTED BY 99MTC-MIBI-SPECT/CT N. Landenberger1, U. Nestle1, G. Gornik2, C. Rischke2, V. Prokic1, M. Mix2, W. Weber2, A. Grosu1 1 University Hospital Freiburg, Radiation Oncology, Freiburg, Germany 2 University Hospital Freiburg, Nuclear Medicine, Freiburg, Germany Purpose/Objective: To evaluate radiation-induced defects of myocardial perfusion following radiation therapy for left-sided breast cancer using 99mTc-MIBI-SPECT/CT (single photon emission computerized tomography – computed tomography).
Conclusions: Despite cobalt machine limitations, Co-f-IMRT technique can replace the use of filters to optimize the dose distribution. EP-0988 COMPARISON OF TWO RADIATION BOOST TECHNIQUES IN PATIENTS UNDERGOING NEOADJUVANT TREATMENT FOR BREAST CANCER L. Nardone1, M.C. De Santis1, B. Diletto1, G.R. D'Agostino1, G. Mattiucci1, R. Canna1, D. Terribile2, G. Franceschini2, A. Mulè3, V. Valentini1 1 Catholic University of the Sacred Heart, Radiation Oncology, Rome, Italy 2 Catholic University of the Sacred Heart, Senology, Rome, Italy 3 Catholic University of the Sacred Heart, Pathology, Rome, Italy Purpose/Objective: Although the use of boost irradiation for women undergoing breast conserving therapy is recommended, the standard technique and the definition of the tumor bed volume have not been clearly established. We retrospectively analyzed two different boost planning techniques, comparing an anticipated preoperative boost technique on the tumor, administered with low dose fractionated radiotherapy (LDFRT), and associated with neoadjuvant chemotherapy, with the standard sequential boost technique to the tumor bed, following surgery and standard whole breast radiotherapy, in order to evaluate the differences in terms of accuracy. Materials and Methods: In our study we retrospectively analyzed a group of patients who received an anticipated preoperative boost on the tumor with LDFRT, for a total dose of 10 Gy by photon technique, and associated with neoadjuvant chemotherapy; for comparison purposes the boost was replanned using a standard electron beam technique to the tumour bed of the same patients, after surgery and standard adjuvant whole breast radiotherapy, for a total dose of 10 Gy over five daily fractions of 2 Gy each. The plans were analyzed for dosimetric coverage of the CT-delineated irradiated volume. The minimal dose received by 95% of the target volume (D95), by 90% of the target volume (D90), and geografic miss were evaluated. A geografic miss was defined as any portion of the tumor bed receiving < 50% of the prescribed dose. Results: Fifteen patients, recruited from 2008 to 2011, were evaluated. We observed 5 patients (33%) with stage IIA, 8 patients (53%) with stage IIB and 2 patient (14%) with stage IIIA. Two patients had lobular cancer and 13 ductal cancer. The grading was G3 in 8 patients and G2 in 7 patients. Median age was 55 years (range 37-70). The standard sequential boost technique resulted in inferior target volume coverage compared with the anticipated boost technique, with a median D95 of 69.2% (range 33.7–86), a median D90 of 75.8% (range 46.7–88.5) and a geografic miss in 27% of patients. The results of the anticipated boost technique were significantly better: 96.8 % (range 94.1–97.8) and 96% (range 92.6–96.8) for median D90 and median D95 respectively and no geografic miss was observed. We observed a dose reduction to heart (with left-sided breast irradiation), using the anticipated preoperative boost technique, when analyzed for all dose-volumes parameters, while the dose to ipsilateral lung resulted higher. Conclusions: Our data show that an anticipated preoperative boost using photons-beam technique allows for optimal tumor bed coverage compared with standard sequential boost after whole breast irradiation using electron-beam technique, preventing geographic misses. Moreover normal tissue may receive less radiation dose, possibly reducing sequential side effects. EP-0989 DETECTION OF MULTIFOCAL/MULTYCENTRIC BREAST CANCER IN CANDIDATES FOR PARTIAL BREAST IRRADIATION S.N. Novikov1, S.V. Kanaev1, P.V. Krivorotko2, V.F. Semiglasov2, L.A. Jukova1, E.V. Kostomina3, U.F. Negustorov3 1 Prof. N.N. Petrov Research Institute of Oncology, Radiation Oncology & Nuclear Medicine, St. Petersburg, Russian Federation 2 Prof. N.N. Petrov Research Institute of Oncology, Breast Cancer, St. Petersburg, Russian Federation 3 Prof. N.N. Petrov Research Institute of Oncology, Radiology, St. Petersburg, Russian Federation Purpose/Objective: Early and accurate diagnosis of multifocal/multycentric breast cancer (MF/MC BC) can be of crucial importance for radiotherapy planning in candidates for partial breast irradiation because in patients (pts) with MF/MC BC whole breast irradiation is preferable strategy. Materials and Methods: We performed retrospective analysis of breast scintigraphy (BSc), mammography (MMg) and ultrasound (US)
ESTRO 31
data in 108 consecutive primary pts that underwent mastectomy with subsequent routine histological examinations of breast specimens. In histological reports only MC BC was described as separate entity so patients with MF BC were analyzed as an additional group. Results: According to histological reports MC BC was diagnosed in 8 of 108 evaluated pts: 7 of 8 pts had scintigraphic sings of MC BC on planar and additional one - on tomography examination. US was positive for MC BC in only one and MMg in none of this 8 pts. MF BC was detected in 13 pts: in 8 cases only by BSc, in 2 - by BSc and US, in 2 - by MMg and US, in 1 - only by MMG. Unfortunately, histological reports does not permit correct evaluation of this cases. Conclusions: 1. BSc can significantly alter radiotherapy strategy in candidates for partial breast irradiation because 7.4% of this pts has MC BC which is revealed by BSc in 87.5%-100% of cases. 2. MF BC can be diagnosed in additional 12% of primary pts but this data is preliminary and need correct histological verification. EP-0990 ADJUVANT BREAST RADIOTHERAPY USING SIMULTANEOUS INTEGRATED BOOST - CLINICAL AND DOSIMETRIC PERSPECTIVES S. Alford1, C. Hamilton1, G. Prassas2 1 Austin Health, Radiation Oncology, Melbourne, Australia 2 Austin Health, Medical School, Melbourne, Australia Purpose/Objective: To determine the rates of late radiotherapy toxicity and cosmetic outcomes in a group of patients with early stage breast cancer treated with adjuvant radiotherapy (RT) using an simultaneous integrated boost (SIB) technique. To perform a dosimetric comparison between SIB and standard sequential boost techniques. Materials and Methods: Patients with early stage breast cancer (pT12 N0-1) treated with conservative surgery and adjuvant RT using an SIB technique were identified retrospectively from the departmental database. RT consisted of 45Gy in 25 fractions delivered to the whole ipsilateral breast with a simultaneous boost to the tumour bed of 60Gy in 25 fractions using a forward-planned conformal technique. Information was collected and analyzed for demographic data, and prospectively collected toxicity and cosmesis measures. Dosimetric assessment was performed on a subset of patients to compare acceptability of PTV coverage and homogeneity and dose to organs at risk. Results: Fifty-five eligible female patients were treated between 2009 and 2011. The median age was 61 years (range, 31 to 81 years). Median follow-up was 13.3 months. Thirty-two patients received adjuvant chemotherapy, eight received Herceptin and 47 received endocrine therapy. The majority of tumours were T1 (n=31), a small proportion had nodal metastases (n=13), of which more than half were macroscopic (n=9). Assessment of SIB forward planned dosimetry confirmed excellent coverage of whole breast and boost target volumes for both right and left-sided tumours. Doses to organs at risk were not increased compared to standard sequential boost plans. Two patients did not have toxicity or cosmesis data available. Of the remaining patients, 98% had a good or excellent cosmetic result based on both patient and physician assessment. Late toxicities including oedema, pigmentation, telangiectasia, fibrosis, osteonecrosis and pain were graded using CTCAE v3.0 criteria; grade 0, 1 and 2 toxicity was assigned to 52.8%, 43.4% and 3.8% of patients. There was no grade 3 or greater toxicity. One patient developed a second primary breast cancer in the contralateral breast. There were no cases of local recurrence. Conclusions: The use of a conformal SIB technique is proposed as a mode of delivering adjuvant RT in early stage breast cancer. This schedule is convenient for patients given shortened overall treatment time, provides adequate dosimetry and doses to organs at risk and is well tolerated with low rates of late toxicity. EP-0991 MYOCARDIAL PERFUSION DEFECTS FOLLOWING RADIOTHERAPY FOR BREAST CANCER DETECTED BY 99MTC-MIBI-SPECT/CT N. Landenberger1, U. Nestle1, G. Gornik2, C. Rischke2, V. Prokic1, M. Mix2, W. Weber2, A. Grosu1 1 University Hospital Freiburg, Radiation Oncology, Freiburg, Germany 2 University Hospital Freiburg, Nuclear Medicine, Freiburg, Germany Purpose/Objective: To evaluate radiation-induced defects of myocardial perfusion following radiation therapy for left-sided breast cancer using 99mTc-MIBI-SPECT/CT (single photon emission computerized tomography – computed tomography).