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138 SECOND CONSERVATIVE TREATMENT FOR IPSILATERAL BREAST CANCER RECURRENCE: GEC-ESTRO BREAST WG STUDY
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PANEL SESSION: 3: REPEAT BREAST CONSERVATION WITH BRACHYTHERAPY 137 REPEAT BREAST CONSERVATION THERAPY: USA EXPERIENCE R. Patel University of Wisconsin, School of Medicine and Public Health, Madison, USA Abstract not received 138 SECOND CONSERVATIVE TREATMENT FOR IPSILATERAL BREAST CANCER RECURRENCE: GEC-ESTRO BREAST WG STUDY J. Hannoun-Levi1, D. Kauer-Dorner2, J. Gal3, V. Strnad4, P. Niehoff5, K. Loessl6, G. Kovacs7, E. Van Limbergen8, C. Polgar9 1 Centre Antoine Lacassagne, Radiation Oncology, Nice, France 2 Medical University of Vienna, Radiation Oncology, Vienna, Austria 3 Centre Antoine Lacassagne, Biostatistic Unit, Nice, France 4 University Erlangen-Nuremberg, Radiation Oncology, Erlangen, Germany 5 University Hospital - SH, Radiation Oncology, Kiel, Germany 6 University Hospital Bernes, Radiation Oncology, Bernes, Switzerland 7 University of Luebeck and University Hospital of Schleswig-Holstein, Radiation Oncology, Luebeck, Germany 8 University Hospital Gasthuisberg, Radiation Oncology, Leuven, Belgium 9 National Institute of Oncology, Radiation Oncology, Budapest, Hungary In case of ipsilateral breast cancer recurrence (IBCR), radical mastectomy represents the treatment option frequently proposed to the patient. A second conservative treatment has been proposed using either lumpectomy alone or associated with a second irradiation of the tumor bed. However, in both clinical situations, the proof level of such therapeutic approaches remains low, based on cased-series or retrospective studies (level C). In order to analyze the clinical outcome of a second conservative treatment (SCT) using lumpectomy and multicatheter interstitial brachytherapy (MIB) for IBCR, the GEC-ESTRO Breast Working Group retrospectively analyzed the results of 217 patients (pts) with an IBCR treated between 09/2000 and 09/2010 in 8 European institutions by lumpectomy and MIB (low - LDR, pulse – PDR, or high-dose rate HDR). Survival rates without 2nd local and metastatic progression, disease free survival (DFS) and specific and overall survivals were analyzed as well as late tissue breast complications and cosmetic results. Dosimetric data were reported according to the dose rate used. Univariate and multivariate analysis were performed to find local, metastatic and/or DFS progression prognostic factors. With a median follow-up of 14.5 years [3.5-38.2] and 3.9 years [1.110.3] from primary tumour and IBCR respectively and a median delay of 9.4 years [1.1-35.4] between primary and IBCR, 20.7% of the local recurrence were observed at distance from the primary tumour. Median tumour sizes were 15 mm [1-60] and 11 mm [1-40] for the primary and IBCR respectively. Sixteen percent of the patients presented a positive lymph node dissection for the primary tumour while 69.1% did not undergo new axillary dissection at the time of IBCR. Median radiotherapy dose for the primary was 56 Gy [30-69.6]. Positive hormonal receptor status for IBCR was 72.8% while 65% and 19.8% received hormonal and chemotherapy respectively as adjuvant therapy for the IBCR. MIB for IBCR used LDR (12.4%), PDR (40.6%) and HDR (47%) with a median delivered dose of 46 Gy [30-55], 50.4 Gy [4950] and 32 Gy [22-36] for LDR, PDR and HDR respectively. Five and 10year actuarial 2nd local recurrence rates were 5.6% [1.5-9.5] and 7.2% [2.1-12.1] respectively. Five and 10-year actuarial metastatic recurrence rates were 9.6% [5.7-15.2] and 19.1% [7.8-28.3] respectively. Five and 10-year actuarial DFS rates were 84.6% [78.990.6] and 77.2% [67.5-88.3] respectively. Five and 10-year actuarial overall/specific survival rates were 88.7% [83.1-94.8] and 76.4% [66.987.3] respectively. One hundred and forty one pts developed 193 complications. Fibrosis was the most frequent complication with 11% of G3-4 complications. Cosmetic result was jugged as excellent/good
World Congress of Brachytherapy 2012 in 85%. Univariate and Multivariate analysis for prognostic factors of 2nd local recurrence, metastatic recurrence and DFS are reported in the table 1. The results of this study suggest that in case of IBCR, a SCT combining lumpectomy plus MIB is feasible with an overall survival rate at least equivalent to those obtain after salvage mastectomy. The rate of complication remains acceptable with encouraging cosmetic results. The data provided by the literature analysis suggest that the rate of second local recurrence is about 10% (ranged from 3 to 32%), about 25% (ranged from 7 to 36%) and about 10% (ranged from 2 to 26%), after salvage mastectomy, salvage lumpectomy alone or combined with a second irradiation of the tumor bed respectively. However, the 5-year overall survival rates after salvage mastectomy and SCT seem to be equivalent (≈ 75%) mainly influenced by distant metastatic progression. To go forward in terms of Evidence Based Medicine, different options can be discussed such as Phase III or II randomized trials comparing salvage mastectomy versus SCT, retrospective studies based on a matched-pair analysis or observatory studies. All of the study designs have their own advantages and disadvantages and need to be carefully analyzed to be able to propose new treatment options for women who experience an IBCR.
PROFFERED PAPERS: PHYSICS 3 OC-139 A FAST AND ACCURATE GPU-BASED PRIMARY+SCATTER ALGORITHM FOR LDR-BRACHYTHERAPY A. Bourque1, P. Després1, L. Beaulieu1 1 Centre Hospitalier Universitaire de Québec, L'Hôtel-Dieu de Québec, Radiation Oncology, Quebec, Canada Purpose/Objective: To improve the accuracy while maintaining fast execution of TG-43 dose calculations with a fast GPU-based raytracing algorithm integrating a point to point scatter dose kernel that handles medium heterogeneities. Materials and Methods: The method developed derives from the TG43 formalism. An incremental version of Siddons’s ray-tracing algorithm is first used to compute radiological distances from sources to dose calculation points. Then, a regular TG-43 dose calculation is performed, with an added correction factor for medium attenuation. Finally, a scatter dose kernel spread the SCERMA energy value around every voxel based on the Thompson approximation of the Compton scattering. Interseed attenuation (ISA) effects and the presence of
PANEL SESSION: 3: REPEAT BREAST CONSERVATION WITH BRACHYTHERAPY 137 REPEAT BREAST CONSERVATION THERAPY: USA EXPERIENCE R. Patel University of Wisconsin, School of Medicine and Public Health, Madison, USA Abstract not received 138 SECOND CONSERVATIVE TREATMENT FOR IPSILATERAL BREAST CANCER RECURRENCE: GEC-ESTRO BREAST WG STUDY J. Hannoun-Levi1, D. Kauer-Dorner2, J. Gal3, V. Strnad4, P. Niehoff5, K. Loessl6, G. Kovacs7, E. Van Limbergen8, C. Polgar9 1 Centre Antoine Lacassagne, Radiation Oncology, Nice, France 2 Medical University of Vienna, Radiation Oncology, Vienna, Austria 3 Centre Antoine Lacassagne, Biostatistic Unit, Nice, France 4 University Erlangen-Nuremberg, Radiation Oncology, Erlangen, Germany 5 University Hospital - SH, Radiation Oncology, Kiel, Germany 6 University Hospital Bernes, Radiation Oncology, Bernes, Switzerland 7 University of Luebeck and University Hospital of Schleswig-Holstein, Radiation Oncology, Luebeck, Germany 8 University Hospital Gasthuisberg, Radiation Oncology, Leuven, Belgium 9 National Institute of Oncology, Radiation Oncology, Budapest, Hungary In case of ipsilateral breast cancer recurrence (IBCR), radical mastectomy represents the treatment option frequently proposed to the patient. A second conservative treatment has been proposed using either lumpectomy alone or associated with a second irradiation of the tumor bed. However, in both clinical situations, the proof level of such therapeutic approaches remains low, based on cased-series or retrospective studies (level C). In order to analyze the clinical outcome of a second conservative treatment (SCT) using lumpectomy and multicatheter interstitial brachytherapy (MIB) for IBCR, the GEC-ESTRO Breast Working Group retrospectively analyzed the results of 217 patients (pts) with an IBCR treated between 09/2000 and 09/2010 in 8 European institutions by lumpectomy and MIB (low - LDR, pulse – PDR, or high-dose rate HDR). Survival rates without 2nd local and metastatic progression, disease free survival (DFS) and specific and overall survivals were analyzed as well as late tissue breast complications and cosmetic results. Dosimetric data were reported according to the dose rate used. Univariate and multivariate analysis were performed to find local, metastatic and/or DFS progression prognostic factors. With a median follow-up of 14.5 years [3.5-38.2] and 3.9 years [1.110.3] from primary tumour and IBCR respectively and a median delay of 9.4 years [1.1-35.4] between primary and IBCR, 20.7% of the local recurrence were observed at distance from the primary tumour. Median tumour sizes were 15 mm [1-60] and 11 mm [1-40] for the primary and IBCR respectively. Sixteen percent of the patients presented a positive lymph node dissection for the primary tumour while 69.1% did not undergo new axillary dissection at the time of IBCR. Median radiotherapy dose for the primary was 56 Gy [30-69.6]. Positive hormonal receptor status for IBCR was 72.8% while 65% and 19.8% received hormonal and chemotherapy respectively as adjuvant therapy for the IBCR. MIB for IBCR used LDR (12.4%), PDR (40.6%) and HDR (47%) with a median delivered dose of 46 Gy [30-55], 50.4 Gy [4950] and 32 Gy [22-36] for LDR, PDR and HDR respectively. Five and 10year actuarial 2nd local recurrence rates were 5.6% [1.5-9.5] and 7.2% [2.1-12.1] respectively. Five and 10-year actuarial metastatic recurrence rates were 9.6% [5.7-15.2] and 19.1% [7.8-28.3] respectively. Five and 10-year actuarial DFS rates were 84.6% [78.990.6] and 77.2% [67.5-88.3] respectively. Five and 10-year actuarial overall/specific survival rates were 88.7% [83.1-94.8] and 76.4% [66.987.3] respectively. One hundred and forty one pts developed 193 complications. Fibrosis was the most frequent complication with 11% of G3-4 complications. Cosmetic result was jugged as excellent/good
World Congress of Brachytherapy 2012 in 85%. Univariate and Multivariate analysis for prognostic factors of 2nd local recurrence, metastatic recurrence and DFS are reported in the table 1. The results of this study suggest that in case of IBCR, a SCT combining lumpectomy plus MIB is feasible with an overall survival rate at least equivalent to those obtain after salvage mastectomy. The rate of complication remains acceptable with encouraging cosmetic results. The data provided by the literature analysis suggest that the rate of second local recurrence is about 10% (ranged from 3 to 32%), about 25% (ranged from 7 to 36%) and about 10% (ranged from 2 to 26%), after salvage mastectomy, salvage lumpectomy alone or combined with a second irradiation of the tumor bed respectively. However, the 5-year overall survival rates after salvage mastectomy and SCT seem to be equivalent (≈ 75%) mainly influenced by distant metastatic progression. To go forward in terms of Evidence Based Medicine, different options can be discussed such as Phase III or II randomized trials comparing salvage mastectomy versus SCT, retrospective studies based on a matched-pair analysis or observatory studies. All of the study designs have their own advantages and disadvantages and need to be carefully analyzed to be able to propose new treatment options for women who experience an IBCR.
PROFFERED PAPERS: PHYSICS 3 OC-139 A FAST AND ACCURATE GPU-BASED PRIMARY+SCATTER ALGORITHM FOR LDR-BRACHYTHERAPY A. Bourque1, P. Després1, L. Beaulieu1 1 Centre Hospitalier Universitaire de Québec, L'Hôtel-Dieu de Québec, Radiation Oncology, Quebec, Canada Purpose/Objective: To improve the accuracy while maintaining fast execution of TG-43 dose calculations with a fast GPU-based raytracing algorithm integrating a point to point scatter dose kernel that handles medium heterogeneities. Materials and Methods: The method developed derives from the TG43 formalism. An incremental version of Siddons’s ray-tracing algorithm is first used to compute radiological distances from sources to dose calculation points. Then, a regular TG-43 dose calculation is performed, with an added correction factor for medium attenuation. Finally, a scatter dose kernel spread the SCERMA energy value around every voxel based on the Thompson approximation of the Compton scattering. Interseed attenuation (ISA) effects and the presence of