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EP-1195: Regional nodal recurrences after adjuvant breast radiotherapy - are we covering the target?
S647 ESTRO 36 _______________________________________________________________________________________________
evaluated through Hosmer-Lemeshow test (HL) and calibration plot. Results a total of 147 breast cancer patients (median age 55 years, range 34–77) were enrolled. Grade 1, 2 and 3 AE were 65/147 (44%), 52/147 (35%) and 24/147 (16%), respectively. At univariate analysis only the dose to 20 cc of breast and use of aromatase inhibitors vs tamoxifen resulted as predictive factors for toxicity (61.8% vs 17.9%, p>0.01, for aromatase inhibitors vs tamoxifen, respectively). ML resulted in a two variable model including the dose to 20 cc of skin (continuous variable, OR=1.09, 10th-90th percentile 1-1.19) and use of aromatase inhibitors (OR=1.7, 10th-90th percentile 1.1-2.7). Calibration was good (HL test p=0.35, calibration slope 1.08). Results for model and calibration are presented in the figure. Smoking also resulted to be a risk factor (OR=4) in a reduced population (87 pts), it was not directly inserted into ML model due to the high prevalence of missing values, but it deserves attention and further analysis
Conclusion this analysis shows that moderate/severe acute skin erythema is related to skin DVH, particularly to the dose to 20cc of skin. In the frame of the here used skin definition, this approximately corresponds to an area of 6x6 cm^2. Use of aromatase inhibitors acts as a dose sensitizing factor for kind of toxicity. EP-1195 Regional nodal recurrences after adjuvant breast radiotherapy – are we covering the target? L.E. Beaton1, L. Nica1, K. Sek2, G. Ayers1, C. Speers3, S. Tyldesley1, A. Nichol1 1 British Columbia Cancer Agency, Radiation Oncology, Vancouver, Canada 2 British Columbia Cancer Agency, Radiology, Vancouver, Canada 3 British Columbia Cancer Agency, Breast Outcomes Unit, Vancouver, Canada Purpose or Objective For all breast cancer patients, adjuvant radiotherapy (RT) reduces locoregional recurrence and for high risk patients, regional nodal irradiation (RNI) improves overall survival. However, there is limited data on the anatomical location of regional nodal recurrence (RNR) after adjuvant RT. Nodal radiotherapy fields have historically been defined using anatomical landmarks but with the advent of 3D radiotherapy planning nodal contouring atlases have been developed. Validation of these atlases is scarce. Our objective was to map the location of RNR in patients previously treated with adjuvant RNI, and assess whether the treating RT fields provided adequate coverage. We also assessed whether these areas of RNR were within the boundaries of the Radiation Therapy Oncology Group (RTOG) nodal atlas. Material and Methods Between 2005 and 2013, we identified 32 patients previously treated with definitive surgery and adjuvant RNI for breast cancer that developed RNR detected with 18-fluorodeoxyglucose positron emission tomography
(FDG-PET) imaging, before salvage treatment for RNR. FDG-PET positive regional lymph nodes were contoured on each individual PET scan. Deformable registration was used to fuse the FDG-PET scan with the patient’s original RT simulation scan, onto which the RTOG atlas had been retrospectively contoured. Each nodal area of recurrence was categorized as: in-field, defined as ≥ 95% of the RNR volume receiving ≥ 95% prescribed dose; marginal, RNR receiving < 95% prescribed dose; and out of field, RNR not intentionally covered with the original RT plan. RTOG coverage was defined for each RNR as ‘inside’, ‘marginal’ or ‘outside’. Results Of the 32 patients, 12 (37%) had limited RNR and 20 (63%) had RNR in addition to distant metastatic di sease on FDGPET imaging. 27 (84%) patients received full axillary RT, 3 (9%) supraclavicular fossa (SCF) only, and 14 (44%) internal mammary node (IMN) RT. Of the 87 nodal relapses, 17 (20%) were out of field. Of those intentionally treated, 10 (33%) patients developed SCF relapse, 18 (66%) axillary relapse and 5 (36%) IMN relapse. 15 (68%) of SCF, 20 (50%) axillary and 1 (14%) IMN nodes were in-field relapses. The RTOG atlas covered 13 (60%) SCF, 20 (50%) axilla and 0 (0%) of IMN nodal relapses.
S648 ESTRO 36 _______________________________________________________________________________________________
Conclusion Despite adjuvant RNI, patients remain at risk of RNR. RNI fields can be optimized, as in our cohort 34 nodes (39%) were marginal, occurring in areas not adequately covered by the prescribed dose. However, 68% of SCF and 50% of axillary relapses were still ‘in-field’, suggesting that either our prescribed dose to these areas was not adequate to control disease, or that these patients were at a high risk of systemic relapse. Use of the RTOG atlas did not provide improved coverage. The anatomical data from this cohort will be used to generate an atlas of nodal relapse that can assist in defining optimal radiotherapy volumes for RNI. Whether inclusion of such regions will alter relapse patterns and event rates is unknown.
Saturation of themes was reached and 6 themes and relative sub-themes were identified. 1) Comprehension & impressions about benefits of the test: pts well understand the aim of the test, a few pts see in this test a tool for improving RT plans depending on individual predisposition to toxicity, but they do not consider it as a tool to independently choose mastectomy or RT. Nevertheless, they think that the test might make them more confident about treatment since it gives additional information. 2) Preliminary preparation to RT and its side effects: the majority of pts felt prepared to RT even if preparation does not always cancel fear. Many women consider important to have the largest and reliable information. Knowing in advance also negative experiences (about toxicity) is a plus point: women want to be aware about the path they are going to follow. 3) Side effects & hypotheses about protective factors: women propose physical/psychological conditions that would have protected them from strong morbidity, as skin color, use of cream, positive attitude, beloved people, visualization techniques. 4) Thoughts about mastectomy vs RT: mastectomy is felt as a very invasive treatment when compared to RT side effects, furthermore, RT toxicity is felt not so serious as a not suitably treated cancer. 5) Emotions: anxiety and fear are insistent feelings, but they are barely connected to genetic test’s result and to the consequent storing of genetic information. 6) Importance of Human Relationships: trust and gratitude versus Hospital/Physician are conditions often more relavant for the treatment choice than the response of a test.
EP-1196 Possible use of genetic tests: let’s consider the opinion of patients S. Gay1, F. Palorini1, M. De Santis2, S. Frasca2, C. West3, T. Rattay4, T. Rancati1, R. Valdagni2, L. Lozza2 1 Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy 2 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiation Oncology 1, Milan, Italy 3 University of Manchester, University of Manchester, Manchester, United Kingdom 4 Christie Hospital, Christie Hospital, Manchester, United Kingdom Purpose or Objective More than half of all women undergoing breast cancer radiotherapy (RT) are anxious about possible changes to appearance of their breast, often causing negative perception of RT. Aim of this work was to explore patients’ views on a potential predictive genetic test that should provide an individual risk probability for toxicity after RT. First, to establish, before any such test is implemented in clinical practice, if such a decision-making tool is acceptable and appropriate for breast cancer pts. Finally, to understand if it would have conditioned the decision-making process with respect the treatment choice (RT + lumpectomy vs mastectomy alone). Material and Methods 11 breast cancer pts undergone semi-structured interviews after RT completion. Interviews were conducted by a radiotherapist and a radiotherapy technician. Thematic analysis was used to analyze the transcripts and identify key themes. Coding was employed to detect common topics and identify sub-themes. Results Characteristic of the 11 pts are reported in figure.
Conclusion Pts opinions underlined that a genetic test could help in facing RT and its side-effect in a more conscious manner, and it might help clinician to optimize RT. Nevertheless side-effect are generally perceivable as tolerable, and preferable to mastectomy or tumor control failure EP-1197 Results in Breast cancer Patients who Received adjuvant Radiation after Immediate Reconstruction A. Giraldo Marin1 1 Hospital Universitario Vall d'Hebron, Radiotherapy, Barcelona, Spain Purpose or Objective Prior studies have advocated avoidance of immediate reconstruction (IR) in breast cancer (BC) patients who should receive adjuvant radiotherapy (RT), alluding to worse aesthetic outcomes. Our purpouse is to evaluate the complication rates and cosmetic results for patients undergoing postmastectomy radiation therapy (PMRT) after IR.
evaluated through Hosmer-Lemeshow test (HL) and calibration plot. Results a total of 147 breast cancer patients (median age 55 years, range 34–77) were enrolled. Grade 1, 2 and 3 AE were 65/147 (44%), 52/147 (35%) and 24/147 (16%), respectively. At univariate analysis only the dose to 20 cc of breast and use of aromatase inhibitors vs tamoxifen resulted as predictive factors for toxicity (61.8% vs 17.9%, p>0.01, for aromatase inhibitors vs tamoxifen, respectively). ML resulted in a two variable model including the dose to 20 cc of skin (continuous variable, OR=1.09, 10th-90th percentile 1-1.19) and use of aromatase inhibitors (OR=1.7, 10th-90th percentile 1.1-2.7). Calibration was good (HL test p=0.35, calibration slope 1.08). Results for model and calibration are presented in the figure. Smoking also resulted to be a risk factor (OR=4) in a reduced population (87 pts), it was not directly inserted into ML model due to the high prevalence of missing values, but it deserves attention and further analysis
Conclusion this analysis shows that moderate/severe acute skin erythema is related to skin DVH, particularly to the dose to 20cc of skin. In the frame of the here used skin definition, this approximately corresponds to an area of 6x6 cm^2. Use of aromatase inhibitors acts as a dose sensitizing factor for kind of toxicity. EP-1195 Regional nodal recurrences after adjuvant breast radiotherapy – are we covering the target? L.E. Beaton1, L. Nica1, K. Sek2, G. Ayers1, C. Speers3, S. Tyldesley1, A. Nichol1 1 British Columbia Cancer Agency, Radiation Oncology, Vancouver, Canada 2 British Columbia Cancer Agency, Radiology, Vancouver, Canada 3 British Columbia Cancer Agency, Breast Outcomes Unit, Vancouver, Canada Purpose or Objective For all breast cancer patients, adjuvant radiotherapy (RT) reduces locoregional recurrence and for high risk patients, regional nodal irradiation (RNI) improves overall survival. However, there is limited data on the anatomical location of regional nodal recurrence (RNR) after adjuvant RT. Nodal radiotherapy fields have historically been defined using anatomical landmarks but with the advent of 3D radiotherapy planning nodal contouring atlases have been developed. Validation of these atlases is scarce. Our objective was to map the location of RNR in patients previously treated with adjuvant RNI, and assess whether the treating RT fields provided adequate coverage. We also assessed whether these areas of RNR were within the boundaries of the Radiation Therapy Oncology Group (RTOG) nodal atlas. Material and Methods Between 2005 and 2013, we identified 32 patients previously treated with definitive surgery and adjuvant RNI for breast cancer that developed RNR detected with 18-fluorodeoxyglucose positron emission tomography
(FDG-PET) imaging, before salvage treatment for RNR. FDG-PET positive regional lymph nodes were contoured on each individual PET scan. Deformable registration was used to fuse the FDG-PET scan with the patient’s original RT simulation scan, onto which the RTOG atlas had been retrospectively contoured. Each nodal area of recurrence was categorized as: in-field, defined as ≥ 95% of the RNR volume receiving ≥ 95% prescribed dose; marginal, RNR receiving < 95% prescribed dose; and out of field, RNR not intentionally covered with the original RT plan. RTOG coverage was defined for each RNR as ‘inside’, ‘marginal’ or ‘outside’. Results Of the 32 patients, 12 (37%) had limited RNR and 20 (63%) had RNR in addition to distant metastatic di sease on FDGPET imaging. 27 (84%) patients received full axillary RT, 3 (9%) supraclavicular fossa (SCF) only, and 14 (44%) internal mammary node (IMN) RT. Of the 87 nodal relapses, 17 (20%) were out of field. Of those intentionally treated, 10 (33%) patients developed SCF relapse, 18 (66%) axillary relapse and 5 (36%) IMN relapse. 15 (68%) of SCF, 20 (50%) axillary and 1 (14%) IMN nodes were in-field relapses. The RTOG atlas covered 13 (60%) SCF, 20 (50%) axilla and 0 (0%) of IMN nodal relapses.
S648 ESTRO 36 _______________________________________________________________________________________________
Conclusion Despite adjuvant RNI, patients remain at risk of RNR. RNI fields can be optimized, as in our cohort 34 nodes (39%) were marginal, occurring in areas not adequately covered by the prescribed dose. However, 68% of SCF and 50% of axillary relapses were still ‘in-field’, suggesting that either our prescribed dose to these areas was not adequate to control disease, or that these patients were at a high risk of systemic relapse. Use of the RTOG atlas did not provide improved coverage. The anatomical data from this cohort will be used to generate an atlas of nodal relapse that can assist in defining optimal radiotherapy volumes for RNI. Whether inclusion of such regions will alter relapse patterns and event rates is unknown.
Saturation of themes was reached and 6 themes and relative sub-themes were identified. 1) Comprehension & impressions about benefits of the test: pts well understand the aim of the test, a few pts see in this test a tool for improving RT plans depending on individual predisposition to toxicity, but they do not consider it as a tool to independently choose mastectomy or RT. Nevertheless, they think that the test might make them more confident about treatment since it gives additional information. 2) Preliminary preparation to RT and its side effects: the majority of pts felt prepared to RT even if preparation does not always cancel fear. Many women consider important to have the largest and reliable information. Knowing in advance also negative experiences (about toxicity) is a plus point: women want to be aware about the path they are going to follow. 3) Side effects & hypotheses about protective factors: women propose physical/psychological conditions that would have protected them from strong morbidity, as skin color, use of cream, positive attitude, beloved people, visualization techniques. 4) Thoughts about mastectomy vs RT: mastectomy is felt as a very invasive treatment when compared to RT side effects, furthermore, RT toxicity is felt not so serious as a not suitably treated cancer. 5) Emotions: anxiety and fear are insistent feelings, but they are barely connected to genetic test’s result and to the consequent storing of genetic information. 6) Importance of Human Relationships: trust and gratitude versus Hospital/Physician are conditions often more relavant for the treatment choice than the response of a test.
EP-1196 Possible use of genetic tests: let’s consider the opinion of patients S. Gay1, F. Palorini1, M. De Santis2, S. Frasca2, C. West3, T. Rattay4, T. Rancati1, R. Valdagni2, L. Lozza2 1 Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy 2 Fondazione IRCCS Istituto Nazionale dei Tumori, Radiation Oncology 1, Milan, Italy 3 University of Manchester, University of Manchester, Manchester, United Kingdom 4 Christie Hospital, Christie Hospital, Manchester, United Kingdom Purpose or Objective More than half of all women undergoing breast cancer radiotherapy (RT) are anxious about possible changes to appearance of their breast, often causing negative perception of RT. Aim of this work was to explore patients’ views on a potential predictive genetic test that should provide an individual risk probability for toxicity after RT. First, to establish, before any such test is implemented in clinical practice, if such a decision-making tool is acceptable and appropriate for breast cancer pts. Finally, to understand if it would have conditioned the decision-making process with respect the treatment choice (RT + lumpectomy vs mastectomy alone). Material and Methods 11 breast cancer pts undergone semi-structured interviews after RT completion. Interviews were conducted by a radiotherapist and a radiotherapy technician. Thematic analysis was used to analyze the transcripts and identify key themes. Coding was employed to detect common topics and identify sub-themes. Results Characteristic of the 11 pts are reported in figure.
Conclusion Pts opinions underlined that a genetic test could help in facing RT and its side-effect in a more conscious manner, and it might help clinician to optimize RT. Nevertheless side-effect are generally perceivable as tolerable, and preferable to mastectomy or tumor control failure EP-1197 Results in Breast cancer Patients who Received adjuvant Radiation after Immediate Reconstruction A. Giraldo Marin1 1 Hospital Universitario Vall d'Hebron, Radiotherapy, Barcelona, Spain Purpose or Objective Prior studies have advocated avoidance of immediate reconstruction (IR) in breast cancer (BC) patients who should receive adjuvant radiotherapy (RT), alluding to worse aesthetic outcomes. Our purpouse is to evaluate the complication rates and cosmetic results for patients undergoing postmastectomy radiation therapy (PMRT) after IR.