- Email: [email protected]
Impact of Regional Nodal Irradiation on Outcomes of Breast Cancer Patients With 1-3 Positive Axillary Nodes
S252
International Journal of Radiation Oncology Biology Physics
demonstrates that web-based information is variable and there are distressing gaps in the information available. Although the assessed websites were mostly accurate, there were significant deficits in authorship, attribution, and currency. Of concern, our research has previously demonstrated that patients use authorship and attribution to determine the reliability of web-based information. Additionally, very few websites provided information regarding prognosis, an area research has identified as an important topic sought by breast cancer patients. The results of this study can be used to counsel patients on the strengths and weaknesses of web-based breast cancer information and to empower patients to choose sites likely to enhance their personal knowledge. Author Disclosure: P. Ingledew: None. B. Brar: None. J. Lin: None. S. Nguyen: None. G. Regehr: None.
Radiation Therapy, University Hospital of Lie`ge, Lie`ge, Belgium, Department of Biostatistics, University Hospital of Lie`ge, Lie`ge, Belgium, 3 Department of Radiation Therapy, Hoˆpital Maisonneuve-Rosemont, Montreal, QC, Canada, 4Department of Radiation Therapy, Centre Franc¸ois Baclesse, Esch sur Alzette, Luxembourg
2088 A Tangled Web: An Evaluation of the Usage of Web-based Information by Breast Cancer Patients P. Ingledew and S. Nguyen; B.C. Cancer Agency - FVCC, Surrey, BC, Canada Purpose/Objective(s): Increasingly cancer patients are researching webbased information to inform their clinical encounter with physicians. Up to 88% of adults online look for health information and cancer is the most common disease for which people seek information. The use of the internet by breast cancer patients is incompletely characterized in the literature. Our prior studies have highlighted deficiencies in the quality of online breast cancer resources and the impact of this on breast cancer patients is unclear. The purpose of this study was to characterize the use of the internet by breast cancer patients describing the way they search for, and the impact of, web-based information on the clinical encounter. Materials/Methods: From September 2011 to January 2012, breast cancer patients presenting at a tertiary cancer center waiting to see their oncologist completed a written 23-question survey. Answers were closed and open-ended. Mixed-methods were used to interpret the quantitative and qualitative data. Results: Eighty-one patients were approached and 56 completed the survey. Sixty-one percent of respondents used the internet daily or weekly and 70% of those respondents searched for breast cancer information. Patients who searched for internet breast cancer information (users) were younger than those who did not use the internet (p Z 0.01). All respondents used Google as their principal search engine and “breast cancer” was the most commonly used search term. In order to select websites for review 60% of users accessed sites from a reputable source or viewed top search engine hits. To evaluate quality 47% of users referred to website author credentials and 37% examined references. All users sought information with respect to treatment and three-quarters sought information on prognosis. Eighty percent of users felt the information on the internet increased their knowledge of breast cancer and the internet influenced treatment decision making for 65% of patients. Thematic analysis revealed that for patients who did not feel the internet was useful, the information was not specific enough, overwhelming, or difficult to interpret. Conclusions: This study highlights search patterns and factors used by patients in seeking web-based breast cancer information. The results illuminate some areas of concern. While patients search for treatment or prognostic information and use citations and authorship for quality evaluation, our prior studies have shown that breast cancer sites lack information on prognosis and there are significant deficiencies in attribution. Physicians must appreciate that breast cancer patients use the internet for information and address discrepancies between the information sought and that which is available. Author Disclosure: P. Ingledew: None. S. Nguyen: None.
2089 Variability of Whole Breast Target Volume Delineation Between Prone and Supine Position: A Multicentric Study F. Lakosi,1 L. Janvary,1 J. Vanderick,1 N. Lombard,1 M. Meyns,1 L. Seidel,2 P. Vavassis,3 M. Untereiner,4 and P. Coucke1; 1Department of
2
Purpose/Objective(s): To determine and compare the interobserver variability of clinical target volume delineation of whole breast (WB) between Prone (Pr) and Supine (Su) position. Materials/Methods: Ten radiation oncologists from three institutions independently delineated WB target volume on the same CT images of three representative breast cancer patients in both positions. By using a point-based approach we determined the 3D coordinates of the most medial (at five different levels from cranial to caudal directions, M1-5), lateral (L1-5), superior (S) and inferior (I) extensions of the contoured volumes in both positions. Three-dimensional vector lengths were calculated between each point and a common reference point placed in the center of the fused volumes. Standard deviations (SD) for each vector were recorded and compared. For each variable (volume, M1-5, L1-5, S, I) mean, SD and coefficient of variation (CV) were calculated per patient and per position. Individual observations of, structure overlap were reported per patient in both positions also. The intra-class correlation coefficient (ICC) with a lower critical limit (ICC*) was calculated to assess the agreement between observers. Results: In 2/3 patients the contoured whole breast volume was considerably higher in Pr than in Su up to an increase of 130%. The worst structure overlap was 65% for both positions, and volume variations had a SD up to just 12% (Su) vs. 10% (Pr). The agreement between observers was good for the breast volume in Su (ICC: 0.92) and in Pr (ICC: 0.89) positions. However, large variability was observed at the different borders of the breast. In Pr, the agreement was good for the points of M1-4 and L25 (ICC: 0.68-0.94). In Su, the agreement was good for the following points: M1-4, L2, L4-5, S, I (ICC: 0.60-0.92). We tabulated some illustrative ICC values for Su and Pr at the most problematic topographical points of the contoured breast volumes. Conclusion: Significantly larger volume for WB could be observed in Pr position. Agreement in the delineation of the WB volume was good in both Pr and Su positions. However, substantial variability remained at the different borders of the breast in both positions. In Pr position less agreement was found in the superior, inferior, upper-lateral and lowermedial limits of the breast. Poster Viewing Abstract 2089; Table
Less satisfactory agreements in Pr and Su
Variables
Prone ICC (inf. bound)
Supine ICC (inf. bound)
Lateral 1 Lateral 3 Medial 5 Superior Inferior
0.46 (0.17) 0.44 (0.13) 0.25 (0.05) 0.04 (-0.03)
0.15 (-0,0) 0.48 (0.19) 0.42 (0.14) -
Author Disclosure: F. Lakosi: None. L. Janvary: None. J. Vanderick: None. N. Lombard: None. M. Meyns: None. L. Seidel: None. P. Vavassis: None. M. Untereiner: None. P. Coucke: None.
2090 Impact of Regional Nodal Irradiation on Outcomes of Breast Cancer Patients With 1-3 Positive Axillary Nodes M.A. Hallman, L. Keller, P. Anderson, and T. Tam; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Routine regional nodal irradiation (RNI) for patients with early stage breast cancer and 1-3 positive axillary lymph nodes (LN) is controversial. For patients with 1-3 positive nodes, comprehensive RNI has typically been reserved for patients who are at greater risk of recurrence. We report our long-term outcomes for women with 1-3 positive LN treated with breast radiation +/- RNI.
Volume 84 Number 3S Supplement 2012 Materials/Methods: Women with 1-3 positive LN treated with lumpectomy and adjuvant radiation (RT) were identified from a prospective database. Women with inflammatory breast cancer; positive margins; <1 year follow-up; treated with neoadjuvant chemotherapy, internal mammary node RT, or an incomplete course of RT were excluded. Patients were stratified by RT to the breast vs. breast + supraclavicular fossa (SCLAV) vs. comprehensive RNI (breast + SCLAV + posterior axillary boost [PAB]). Site of failure, disease free survival (DFS), breast cancer-specific (BCSS), overall survival (OS), and lymphedema rates were evaluated. Results: Five hundred forty-two patients were identified with median follow-up of 7.5 years. Three hundred fifty-nine (66.2%), 109 (20.1%) and 74 (13.7%) patients had RT to the breast alone, breast + SCLAV, and comprehensive RNI, respectively. Compared to breast RT only, higher T stage, 2 positive LN and unknown hormone receptor status, HER2/neu status, extracapsular extension (ECE), lymphovascular invasion (LVI), and tumor grade were more common in women with breast + SCLAV RT (p < 0.05.) Compared to breast + SCLV RT, 2 positive LN and unknown HER2/neu, extensive intraductal component, ECE, and LVI were more common with comprehensive RNI (p < 0.05). There were 8 (1.5%) any regional failures. The rates of regional and local/regional failure were not statistically different among the groups. At 5 years, distant failures were more common in the comprehensive RNI group (19.6%) vs. breast only (9.0%) and breast + SCLAV (9.9%) groups (p Z 0.01). On multivariate analysis, the comprehensive RNI group remained at greater risk for any distant failure (HR 1.74, p Z 0.049); T2 vs. T1 (HR 1.98, p Z 0.004) also remained significantly associated with increased distant failure. BCSS was lower in the comprehensive RNI group (85.7%) vs. breast only (94.5%) and breast +SCLAV (93.1%) groups (p Z 0.01). On multivariate analysis comprehensive RNI was not significantly associated with BCSS (p Z 0.06). DFS and OS were not different among the groups. The number of LN dissected was similar in all groups; however, lymphedema rates were higher among the breast + SCLAV (24.8%) and comprehensive RNI (28.4%) groups vs breast only group (15.6%, p Z 0.01). Conclusions: Locoregional control, DFS, BCSS, and OS were excellent in women with 1-3 positive LN, despite differences in RNI. Lymphedema rates were higher following RNI. Thus, RNI should be considered only when there is known potential benefit. Author Disclosure: M.A. Hallman: None. L. Keller: None. P. Anderson: None. T. Tam: None.
2091 Long-term Results of Accelerated Partial Breast Irradiation (APBI) for Early Stage Node Negative Breast Cancer Treated by Balloon Catheter: Evaluation of Loco-regional Recurrence and Cosmesis With Respect to Body Mass Index (BMI) A. Ravi,1,2 A. Osian,3 C. Sison,4 and D. Nori1; 1Weill Cornell Medical College, New York, NY, 2New York Hospital Queens, Flushing, NY, 3New York Hospital Queens, Flushing, NY, 4Biostatistics Unit, Feinstein Institute for Medical Research North Shore-LIJ Health System, Manhasset, NY Purpose/Objective(s): There is data that suggests that there is association between obesity and poorer breast cancer outcomes. We evaluated BMI and its impact on ipsilateral breast tumor recurrence (IBTR), cosmesis, and incidence of other malignancies in early stage breast cancer patients treated by APBI using the MammoSite. Materials/Methods: Between June 2003 and December 2009, 83 postmenopausal patients (76 invasive ductal carcinoma (IDC), 7 Ductal carcinoma in situ (DCIS) with a diagnosis of early stage breast cancer and node negative status met our inclusion criteria for (APBI) using the single lumen balloon catheter (SLM). A dose of 3400 cGy was prescribed in 10 fractions at distance of 1cm from surface of balloon delivered twice daily, 6 hours apart using the high dose rate system. BMI was classified as 18.5 to <25Kg/m2 (normal, NL), 25- <30Kg/m2 (overweight, OV), 30-39kg/m2 (obese, OB), >40Kg/m2 (extreme obese, EO). Cosmesis was graded as
Poster Viewing Abstracts S253 Excellent/Good (E/G) vs. Fair/Poor (F/P). Bra and cup sizes were categorized. Mann Whitney test or t-test was used to compare groups with respect to BMI and dosimetric parameters. Overall survival was estimated using the K-M method. Results: Mean age of 83 patients was 72.65.Mean BMI was 30.346.23 (range: 21 to 54). Median follow-up was 66.5 months. Adjuvant chemotherapy was given in 18% (14/76) and hormones in 85% ER+ IDC patients. IBTR occurred in 2/83 patients at 93.5 months (ER+, PR+, HER2-, BMI Z 24.5, normal, cosmesis Z GOOD) and 47.2 months (ER-, PR-, HER2+, BMI Z 33.4, obese, cosmesis Z GOOD), respectively. There were increased number of grade 2/3 tumors in the OB/EO group than NL/OV (82.86% (29/35) vs. 55.3% (26/47); p < 0.01). Cosmesis was excellent or good in 98% and there was no significant association with BMI, Bra, or cup size or with any dosimetric parameters. There were 17 ‘other malignancies’ (20.5%). A higher proportion of OB/EO developed ‘other malignancies’ compared to others, and was not statistically significant (25.7% (9/35) vs. 16.7% (8/48); p Z .41). Twelve deaths were unrelated to breast cancer. The overall 5-year survival was 86.7% (95% CI: (75.8% to 92.9%)). Conclusions: At median follow up of 66 months, APBI treatment using balloon catheter resulted in 97.6% locoregional control with excellentGood cosmesis. There was no significant association with BMI and outcomes or cosmesis in this study. This should be further investigated in a larger study. Author Disclosure: A. Ravi: None. A. Osian: None. C. Sison: None. D. Nori: None.
2092 Late Toxicity and Cosmetic Outcome in Patients With Breast Cancer Treated With Intraoperative Radiation Therapy as an Electron Boost M. Govers,1 R. Weytjens,1 K. Erven,1 P. van Dam,2 S. Van Laere,3 A. Prove´,4 J. Alberty,1 R. Reymen,1 M. Vos,1 and P. Huget1; 1Department of Radiation Oncology, Iridium Kankernetwerk, Antwerp, Belgium, 2 Department of Gynaecological Oncology, Iridium Kankernetwerk, Antwerp, Belgium, 3Translational Cancer Research Unit, Iridium Kankernetwerk, Antwerp, Belgium, 4Department of Oncology, Iridium Kankernetwerk, Antwerp, Belgium Purpose/Objective(s): Using intra-operative radiation therapy (IORT) as a boost after breast conserving surgery (BCS), late-reacting tissue is exposed to a single high dose. Therefore, late toxicity is of particular interest. We aimed to compare late toxicity and cosmetic results in patients receiving standard treatment with different radiation therapy boost strategies. Materials/Methods: One hundred thirty women with T1 or T2 breast tumors received BCS and postoperative 50 Gy of external beam radiation therapy (EBRT) to the whole breast in 2 Gy fractions. Group 1 (n Z 72) received a 9 Gy IORT electron boost directly to the tumor bed using a mobile electron linear accelerator. Group 2 (n Z 58) received an EBRT electron boost or a pulsed dose rate brachytherapy boost after whole breast irradiation. Patient groups were comparable for age, menopausal status, histological tumor type, tumor grading, and adjuvant chemotherapy. Late toxicity and global cosmetic results were scored according to the LENT SOMA scale and four-point scale respectively. Results: After a median follow-up period of 40 [24-56] months in group 1 and 45 [20-57] months in group 2, there was no significant difference in late toxicity rates. The observed rates of grade 3 or 4 toxicity in group 1 and 2 were 1.4% versus 0% for atrophy, 4.2% versus 5.2% for fibrosis, 0% versus 1.7% for telangiectasia and 0% versus 1.7% for pain. Cosmetic outcome was not significantly different between both groups, and was good to excellent in most patients, with only 2 patients in group 1 and 1 patient in group 2 having a poor cosmetic outcome. Group 1 patients receiving adjuvant chemotherapy had a significantly higher rate of highgrade toxicity, compared to patients receiving no chemotherapy. This finding was not observed in group 2 and we found no such correlation for adjuvant hormonal therapy. Finally, there was no significant difference in amount of distortions on follow-up imaging between group 1 and 2.
International Journal of Radiation Oncology Biology Physics
demonstrates that web-based information is variable and there are distressing gaps in the information available. Although the assessed websites were mostly accurate, there were significant deficits in authorship, attribution, and currency. Of concern, our research has previously demonstrated that patients use authorship and attribution to determine the reliability of web-based information. Additionally, very few websites provided information regarding prognosis, an area research has identified as an important topic sought by breast cancer patients. The results of this study can be used to counsel patients on the strengths and weaknesses of web-based breast cancer information and to empower patients to choose sites likely to enhance their personal knowledge. Author Disclosure: P. Ingledew: None. B. Brar: None. J. Lin: None. S. Nguyen: None. G. Regehr: None.
Radiation Therapy, University Hospital of Lie`ge, Lie`ge, Belgium, Department of Biostatistics, University Hospital of Lie`ge, Lie`ge, Belgium, 3 Department of Radiation Therapy, Hoˆpital Maisonneuve-Rosemont, Montreal, QC, Canada, 4Department of Radiation Therapy, Centre Franc¸ois Baclesse, Esch sur Alzette, Luxembourg
2088 A Tangled Web: An Evaluation of the Usage of Web-based Information by Breast Cancer Patients P. Ingledew and S. Nguyen; B.C. Cancer Agency - FVCC, Surrey, BC, Canada Purpose/Objective(s): Increasingly cancer patients are researching webbased information to inform their clinical encounter with physicians. Up to 88% of adults online look for health information and cancer is the most common disease for which people seek information. The use of the internet by breast cancer patients is incompletely characterized in the literature. Our prior studies have highlighted deficiencies in the quality of online breast cancer resources and the impact of this on breast cancer patients is unclear. The purpose of this study was to characterize the use of the internet by breast cancer patients describing the way they search for, and the impact of, web-based information on the clinical encounter. Materials/Methods: From September 2011 to January 2012, breast cancer patients presenting at a tertiary cancer center waiting to see their oncologist completed a written 23-question survey. Answers were closed and open-ended. Mixed-methods were used to interpret the quantitative and qualitative data. Results: Eighty-one patients were approached and 56 completed the survey. Sixty-one percent of respondents used the internet daily or weekly and 70% of those respondents searched for breast cancer information. Patients who searched for internet breast cancer information (users) were younger than those who did not use the internet (p Z 0.01). All respondents used Google as their principal search engine and “breast cancer” was the most commonly used search term. In order to select websites for review 60% of users accessed sites from a reputable source or viewed top search engine hits. To evaluate quality 47% of users referred to website author credentials and 37% examined references. All users sought information with respect to treatment and three-quarters sought information on prognosis. Eighty percent of users felt the information on the internet increased their knowledge of breast cancer and the internet influenced treatment decision making for 65% of patients. Thematic analysis revealed that for patients who did not feel the internet was useful, the information was not specific enough, overwhelming, or difficult to interpret. Conclusions: This study highlights search patterns and factors used by patients in seeking web-based breast cancer information. The results illuminate some areas of concern. While patients search for treatment or prognostic information and use citations and authorship for quality evaluation, our prior studies have shown that breast cancer sites lack information on prognosis and there are significant deficiencies in attribution. Physicians must appreciate that breast cancer patients use the internet for information and address discrepancies between the information sought and that which is available. Author Disclosure: P. Ingledew: None. S. Nguyen: None.
2089 Variability of Whole Breast Target Volume Delineation Between Prone and Supine Position: A Multicentric Study F. Lakosi,1 L. Janvary,1 J. Vanderick,1 N. Lombard,1 M. Meyns,1 L. Seidel,2 P. Vavassis,3 M. Untereiner,4 and P. Coucke1; 1Department of
2
Purpose/Objective(s): To determine and compare the interobserver variability of clinical target volume delineation of whole breast (WB) between Prone (Pr) and Supine (Su) position. Materials/Methods: Ten radiation oncologists from three institutions independently delineated WB target volume on the same CT images of three representative breast cancer patients in both positions. By using a point-based approach we determined the 3D coordinates of the most medial (at five different levels from cranial to caudal directions, M1-5), lateral (L1-5), superior (S) and inferior (I) extensions of the contoured volumes in both positions. Three-dimensional vector lengths were calculated between each point and a common reference point placed in the center of the fused volumes. Standard deviations (SD) for each vector were recorded and compared. For each variable (volume, M1-5, L1-5, S, I) mean, SD and coefficient of variation (CV) were calculated per patient and per position. Individual observations of, structure overlap were reported per patient in both positions also. The intra-class correlation coefficient (ICC) with a lower critical limit (ICC*) was calculated to assess the agreement between observers. Results: In 2/3 patients the contoured whole breast volume was considerably higher in Pr than in Su up to an increase of 130%. The worst structure overlap was 65% for both positions, and volume variations had a SD up to just 12% (Su) vs. 10% (Pr). The agreement between observers was good for the breast volume in Su (ICC: 0.92) and in Pr (ICC: 0.89) positions. However, large variability was observed at the different borders of the breast. In Pr, the agreement was good for the points of M1-4 and L25 (ICC: 0.68-0.94). In Su, the agreement was good for the following points: M1-4, L2, L4-5, S, I (ICC: 0.60-0.92). We tabulated some illustrative ICC values for Su and Pr at the most problematic topographical points of the contoured breast volumes. Conclusion: Significantly larger volume for WB could be observed in Pr position. Agreement in the delineation of the WB volume was good in both Pr and Su positions. However, substantial variability remained at the different borders of the breast in both positions. In Pr position less agreement was found in the superior, inferior, upper-lateral and lowermedial limits of the breast. Poster Viewing Abstract 2089; Table
Less satisfactory agreements in Pr and Su
Variables
Prone ICC (inf. bound)
Supine ICC (inf. bound)
Lateral 1 Lateral 3 Medial 5 Superior Inferior
0.46 (0.17) 0.44 (0.13) 0.25 (0.05) 0.04 (-0.03)
0.15 (-0,0) 0.48 (0.19) 0.42 (0.14) -
Author Disclosure: F. Lakosi: None. L. Janvary: None. J. Vanderick: None. N. Lombard: None. M. Meyns: None. L. Seidel: None. P. Vavassis: None. M. Untereiner: None. P. Coucke: None.
2090 Impact of Regional Nodal Irradiation on Outcomes of Breast Cancer Patients With 1-3 Positive Axillary Nodes M.A. Hallman, L. Keller, P. Anderson, and T. Tam; Fox Chase Cancer Center, Philadelphia, PA Purpose/Objective(s): Routine regional nodal irradiation (RNI) for patients with early stage breast cancer and 1-3 positive axillary lymph nodes (LN) is controversial. For patients with 1-3 positive nodes, comprehensive RNI has typically been reserved for patients who are at greater risk of recurrence. We report our long-term outcomes for women with 1-3 positive LN treated with breast radiation +/- RNI.
Volume 84 Number 3S Supplement 2012 Materials/Methods: Women with 1-3 positive LN treated with lumpectomy and adjuvant radiation (RT) were identified from a prospective database. Women with inflammatory breast cancer; positive margins; <1 year follow-up; treated with neoadjuvant chemotherapy, internal mammary node RT, or an incomplete course of RT were excluded. Patients were stratified by RT to the breast vs. breast + supraclavicular fossa (SCLAV) vs. comprehensive RNI (breast + SCLAV + posterior axillary boost [PAB]). Site of failure, disease free survival (DFS), breast cancer-specific (BCSS), overall survival (OS), and lymphedema rates were evaluated. Results: Five hundred forty-two patients were identified with median follow-up of 7.5 years. Three hundred fifty-nine (66.2%), 109 (20.1%) and 74 (13.7%) patients had RT to the breast alone, breast + SCLAV, and comprehensive RNI, respectively. Compared to breast RT only, higher T stage, 2 positive LN and unknown hormone receptor status, HER2/neu status, extracapsular extension (ECE), lymphovascular invasion (LVI), and tumor grade were more common in women with breast + SCLAV RT (p < 0.05.) Compared to breast + SCLV RT, 2 positive LN and unknown HER2/neu, extensive intraductal component, ECE, and LVI were more common with comprehensive RNI (p < 0.05). There were 8 (1.5%) any regional failures. The rates of regional and local/regional failure were not statistically different among the groups. At 5 years, distant failures were more common in the comprehensive RNI group (19.6%) vs. breast only (9.0%) and breast + SCLAV (9.9%) groups (p Z 0.01). On multivariate analysis, the comprehensive RNI group remained at greater risk for any distant failure (HR 1.74, p Z 0.049); T2 vs. T1 (HR 1.98, p Z 0.004) also remained significantly associated with increased distant failure. BCSS was lower in the comprehensive RNI group (85.7%) vs. breast only (94.5%) and breast +SCLAV (93.1%) groups (p Z 0.01). On multivariate analysis comprehensive RNI was not significantly associated with BCSS (p Z 0.06). DFS and OS were not different among the groups. The number of LN dissected was similar in all groups; however, lymphedema rates were higher among the breast + SCLAV (24.8%) and comprehensive RNI (28.4%) groups vs breast only group (15.6%, p Z 0.01). Conclusions: Locoregional control, DFS, BCSS, and OS were excellent in women with 1-3 positive LN, despite differences in RNI. Lymphedema rates were higher following RNI. Thus, RNI should be considered only when there is known potential benefit. Author Disclosure: M.A. Hallman: None. L. Keller: None. P. Anderson: None. T. Tam: None.
2091 Long-term Results of Accelerated Partial Breast Irradiation (APBI) for Early Stage Node Negative Breast Cancer Treated by Balloon Catheter: Evaluation of Loco-regional Recurrence and Cosmesis With Respect to Body Mass Index (BMI) A. Ravi,1,2 A. Osian,3 C. Sison,4 and D. Nori1; 1Weill Cornell Medical College, New York, NY, 2New York Hospital Queens, Flushing, NY, 3New York Hospital Queens, Flushing, NY, 4Biostatistics Unit, Feinstein Institute for Medical Research North Shore-LIJ Health System, Manhasset, NY Purpose/Objective(s): There is data that suggests that there is association between obesity and poorer breast cancer outcomes. We evaluated BMI and its impact on ipsilateral breast tumor recurrence (IBTR), cosmesis, and incidence of other malignancies in early stage breast cancer patients treated by APBI using the MammoSite. Materials/Methods: Between June 2003 and December 2009, 83 postmenopausal patients (76 invasive ductal carcinoma (IDC), 7 Ductal carcinoma in situ (DCIS) with a diagnosis of early stage breast cancer and node negative status met our inclusion criteria for (APBI) using the single lumen balloon catheter (SLM). A dose of 3400 cGy was prescribed in 10 fractions at distance of 1cm from surface of balloon delivered twice daily, 6 hours apart using the high dose rate system. BMI was classified as 18.5 to <25Kg/m2 (normal, NL), 25- <30Kg/m2 (overweight, OV), 30-39kg/m2 (obese, OB), >40Kg/m2 (extreme obese, EO). Cosmesis was graded as
Poster Viewing Abstracts S253 Excellent/Good (E/G) vs. Fair/Poor (F/P). Bra and cup sizes were categorized. Mann Whitney test or t-test was used to compare groups with respect to BMI and dosimetric parameters. Overall survival was estimated using the K-M method. Results: Mean age of 83 patients was 72.65.Mean BMI was 30.346.23 (range: 21 to 54). Median follow-up was 66.5 months. Adjuvant chemotherapy was given in 18% (14/76) and hormones in 85% ER+ IDC patients. IBTR occurred in 2/83 patients at 93.5 months (ER+, PR+, HER2-, BMI Z 24.5, normal, cosmesis Z GOOD) and 47.2 months (ER-, PR-, HER2+, BMI Z 33.4, obese, cosmesis Z GOOD), respectively. There were increased number of grade 2/3 tumors in the OB/EO group than NL/OV (82.86% (29/35) vs. 55.3% (26/47); p < 0.01). Cosmesis was excellent or good in 98% and there was no significant association with BMI, Bra, or cup size or with any dosimetric parameters. There were 17 ‘other malignancies’ (20.5%). A higher proportion of OB/EO developed ‘other malignancies’ compared to others, and was not statistically significant (25.7% (9/35) vs. 16.7% (8/48); p Z .41). Twelve deaths were unrelated to breast cancer. The overall 5-year survival was 86.7% (95% CI: (75.8% to 92.9%)). Conclusions: At median follow up of 66 months, APBI treatment using balloon catheter resulted in 97.6% locoregional control with excellentGood cosmesis. There was no significant association with BMI and outcomes or cosmesis in this study. This should be further investigated in a larger study. Author Disclosure: A. Ravi: None. A. Osian: None. C. Sison: None. D. Nori: None.
2092 Late Toxicity and Cosmetic Outcome in Patients With Breast Cancer Treated With Intraoperative Radiation Therapy as an Electron Boost M. Govers,1 R. Weytjens,1 K. Erven,1 P. van Dam,2 S. Van Laere,3 A. Prove´,4 J. Alberty,1 R. Reymen,1 M. Vos,1 and P. Huget1; 1Department of Radiation Oncology, Iridium Kankernetwerk, Antwerp, Belgium, 2 Department of Gynaecological Oncology, Iridium Kankernetwerk, Antwerp, Belgium, 3Translational Cancer Research Unit, Iridium Kankernetwerk, Antwerp, Belgium, 4Department of Oncology, Iridium Kankernetwerk, Antwerp, Belgium Purpose/Objective(s): Using intra-operative radiation therapy (IORT) as a boost after breast conserving surgery (BCS), late-reacting tissue is exposed to a single high dose. Therefore, late toxicity is of particular interest. We aimed to compare late toxicity and cosmetic results in patients receiving standard treatment with different radiation therapy boost strategies. Materials/Methods: One hundred thirty women with T1 or T2 breast tumors received BCS and postoperative 50 Gy of external beam radiation therapy (EBRT) to the whole breast in 2 Gy fractions. Group 1 (n Z 72) received a 9 Gy IORT electron boost directly to the tumor bed using a mobile electron linear accelerator. Group 2 (n Z 58) received an EBRT electron boost or a pulsed dose rate brachytherapy boost after whole breast irradiation. Patient groups were comparable for age, menopausal status, histological tumor type, tumor grading, and adjuvant chemotherapy. Late toxicity and global cosmetic results were scored according to the LENT SOMA scale and four-point scale respectively. Results: After a median follow-up period of 40 [24-56] months in group 1 and 45 [20-57] months in group 2, there was no significant difference in late toxicity rates. The observed rates of grade 3 or 4 toxicity in group 1 and 2 were 1.4% versus 0% for atrophy, 4.2% versus 5.2% for fibrosis, 0% versus 1.7% for telangiectasia and 0% versus 1.7% for pain. Cosmetic outcome was not significantly different between both groups, and was good to excellent in most patients, with only 2 patients in group 1 and 1 patient in group 2 having a poor cosmetic outcome. Group 1 patients receiving adjuvant chemotherapy had a significantly higher rate of highgrade toxicity, compared to patients receiving no chemotherapy. This finding was not observed in group 2 and we found no such correlation for adjuvant hormonal therapy. Finally, there was no significant difference in amount of distortions on follow-up imaging between group 1 and 2.