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Impact on Lung Dose in Left Breast Radiation Therapy Patients With Deep Inspiration Breath Hold Versus Free Breathing Technique
E52
International Journal of Radiation Oncology Biology Physics
Conclusion: Decisions regarding RT use after NAC are most strongly driven by clinical nodal stage prior to NAC. Reconstruction was more strongly predictive of omitting RT than widely accepted prognostic factors, such as receptor status and pathologic nodal stage. Inconsistent use of RT in women undergoing reconstruction raises concerns regarding how this elective cosmetic procedure influences the decision to administer RT. Greater consensus regarding appropriate indications for post-NAC RT is required. Author Disclosure: C.T. Murphy: None. E. Handorf: None. E.R. Sigurdson: None. S.B. Hayes: None. P. Anderson: None. S. Weiss: None. T. Shaikh: None. J.M. Daly: None. M. Boraas: None. R.J. Bleicher: None.
image fusion and overlay of the image data sets. This identified whether the patient would be benefited with DIBH technique. The treatment plans were constructed using forward planning for tangential field setup for both CT image sets. The coverage of PTV and dose to ipsilateral lung were evaluated and compared. A comparison of the ipsilateral lung volume receiving 20% of prescription dose (V20) was used to show if there were any dosimetric advantages using the DIBH technique. Results: Upon comparing the two CT simulated images, the difference in the height of vertical distance yielded a range from 0.3 to 1.9 cm. This measurement corresponded to the change of the vertical (anterior-posterior) distance at the medial border between DIBH and FB images. The results indicated that V20 of the ipsilateral lung in patients with a vertical distance range of 1.9 cm to 0.8 cm was 9% to 36% lower for the DIBH plans compared to the FB plans. For patients with a vertical distance range of 0.8 cm to 0.3 cm, the difference between DIBH and FB plans was less significant, as expected. The V20 of the ipsilateral lung DIBH plans were 0 to 22% lower in comparison to the FB plans. Conclusion: These results indicate that treating left-sided breast cancer patients with DIBH technique yields dosimetric advantages. With a deeper inspiration, which yields a greater difference in the height of the vertical distance, the dose to the ipsilateral lung can be reduced significantly. Hence, in order to reduce lung dose further, patients should be instructed to attempt deeper inhalation. Author Disclosure: L. Vijeh: None. Y. Ahmed: None. L. Lee: None. Y. Cao: None.
2125 Adjuvant Radiation Therapy for Older Women With Early-Stage Hormone Receptor–Positive and HER2-Negative Breast Cancer: An Analysis of the National Cancer Data Base A. Herskovic, X. Wu, P. Christos, H. Nagar, and S. Formenti; New YorkPresbyterian Hospital/Weill Cornell Medicine, New York, NY Purpose/Objective(s): The role of adjuvant radiation therapy (RT) in the treatment for early-stage hormone receptor positive and HER2 negative breast cancer in older women after breast conservation therapy remains controversial. We investigated national practice patterns and outcomes for these patients using the National Cancer Database (NCDB). Materials/Methods: Women aged 65 years and older with hormone receptor positive and HER2 negative pathologic T1-T2N0M0 measuring up to 3 cm invasive breast cancer who were treated with breast conservation and adjuvant endocrine therapy without adjuvant chemotherapy from 2006-2013 were identified and stratified by the use of adjuvant RT. Multivariable proportional hazards modelling was used to examine the association of treatment and mortality adjusting for demographic, socioeconomic and clinicopathologic factors. Results: A total of 61,395 patients with a median follow-up of 48.7 months (range 0-107) were identified. Improved overall survival was associated with younger age, facility type, income level, lower Charlson-Deyo comorbidity index, lower stage, smaller tumor size, number of nodes examined, and receipt of adjuvant RT (all P<.05). The overall 5-year survival rate was 93.0% (95% confidence interval 92.7%-93.3%) in the adjuvant RT group and 83.6% (95% confidence interval 82.5%-84.7%) in the non-adjuvant RT group (P<.0001). Conclusion: Improved survival is associated with receipt of adjuvant radiation therapy for older women with early-stage hormone receptor positive HER2 negative breast cancer who received adjuvant endocrine therapy. Author Disclosure: A. Herskovic: None. X. Wu: None. P. Christos: None. H. Nagar: None. S. Formenti: Research Grant; Regeneron, Jansseen Biotech, Eli Lilly. Speaker’s Bureau; Varian. Advisory Committee; Smith Kline. Advisory Committee; BMS, Astra Zeneca, EISAI.
2126 Impact on Lung Dose in Left Breast Radiation Therapy Patients With Deep Inspiration Breath Hold Versus Free Breathing Technique L. Vijeh, Y. Ahmed, L. Lee, and Y. Cao; Northwell Health, Lake Success, NY Purpose/Objective(s): This study evaluates lung dose for deep inspiration breath hold (DIBH) versus free breathing (FB) technique in patients with left-sided breast cancer. Materials/Methods: This is a retrospective study of 20 patients with left-sided breast cancer who underwent radiation therapy to evaluate for ipsilateral lung dose between the use of DIBH technique and FB. At the simulation, CT images were acquired with DIBH as well as FB, in two separate scans. The variation of chest motion was assessed by
2127 Practice Patterns and Outcomes for Postmastectomy Radiation After Complete Pathological Response in Stage II and IIIA Breast Cancer Patients: Analysis of the National Cancer Data Base J. Chen, X. Wu, P. Christos, D. Nori, S. Formenti, and H. Nagar; New YorkPresbyterian Hospital/Weill Cornell Medicine, New York, NY Purpose/Objective(s): In the management of breast cancer, neoadjuvant chemotherapy (NAC) allows conversion from mastectomy to breast conservation surgery in some patients, and it also provides valuable information on pathological response of the cancer to chemotherapy. However, the role of post-mastectomy radiation therapy (PMRT) is not clear following NAC, especially in the setting of a pathologic complete response (pCR). In the absence of any published prospective randomized studies, retrospective reports have attempted to provide information delineating the selection of patients that benefit from PMRT. Much of these data have come from MDACC reports, where preliminary results indicate survival benefit of PMRT in patients with stage IIIB disease, and local control benefit in stage III and possibly in T3N0 patients. In this report, we add to the available retrospective evidence regarding which patients benefit and which may be able to forego PMRT in this setting. Methods/Materials: Women with stage IIA (excluding T2N0), IIB, and IIIA breast cancer who had a complete pathological response to neoadjuvant chemotherapy (as defined by no invasive carcinoma seen in surgical pathology in breast and nodes) were identified in the NCDB from 2004 e 2013. A total of 1584 patients were identified and multivariable proportional hazards modelling was used to examine the association of treatment and mortality adjusting for demographic, socioeconomic and clinicopathologic factors. Results: A total of 1,584 patients met all inclusion criteria, with a median follow-up of 39 months. Of these, 935 (59.0%) received PMRT and 649 (41.0%) did not. In the group that received PMRT, 94.35% were alive at 3 years, compared to 93.98% in the group that did not receive PMRT (P Z 0.60). Conclusion: PMRT did not significantly impact survival in women with node-positive stage IIA, stage IIB, and stage IIIA breast cancer who had pCR after NAC, at a short median follow up of 39 months. The findings are biased by the retrospective nature of this analysis and the interplay of other variables that were not measured. Prospective randomized trials will elucidate this important issue.
International Journal of Radiation Oncology Biology Physics
Conclusion: Decisions regarding RT use after NAC are most strongly driven by clinical nodal stage prior to NAC. Reconstruction was more strongly predictive of omitting RT than widely accepted prognostic factors, such as receptor status and pathologic nodal stage. Inconsistent use of RT in women undergoing reconstruction raises concerns regarding how this elective cosmetic procedure influences the decision to administer RT. Greater consensus regarding appropriate indications for post-NAC RT is required. Author Disclosure: C.T. Murphy: None. E. Handorf: None. E.R. Sigurdson: None. S.B. Hayes: None. P. Anderson: None. S. Weiss: None. T. Shaikh: None. J.M. Daly: None. M. Boraas: None. R.J. Bleicher: None.
image fusion and overlay of the image data sets. This identified whether the patient would be benefited with DIBH technique. The treatment plans were constructed using forward planning for tangential field setup for both CT image sets. The coverage of PTV and dose to ipsilateral lung were evaluated and compared. A comparison of the ipsilateral lung volume receiving 20% of prescription dose (V20) was used to show if there were any dosimetric advantages using the DIBH technique. Results: Upon comparing the two CT simulated images, the difference in the height of vertical distance yielded a range from 0.3 to 1.9 cm. This measurement corresponded to the change of the vertical (anterior-posterior) distance at the medial border between DIBH and FB images. The results indicated that V20 of the ipsilateral lung in patients with a vertical distance range of 1.9 cm to 0.8 cm was 9% to 36% lower for the DIBH plans compared to the FB plans. For patients with a vertical distance range of 0.8 cm to 0.3 cm, the difference between DIBH and FB plans was less significant, as expected. The V20 of the ipsilateral lung DIBH plans were 0 to 22% lower in comparison to the FB plans. Conclusion: These results indicate that treating left-sided breast cancer patients with DIBH technique yields dosimetric advantages. With a deeper inspiration, which yields a greater difference in the height of the vertical distance, the dose to the ipsilateral lung can be reduced significantly. Hence, in order to reduce lung dose further, patients should be instructed to attempt deeper inhalation. Author Disclosure: L. Vijeh: None. Y. Ahmed: None. L. Lee: None. Y. Cao: None.
2125 Adjuvant Radiation Therapy for Older Women With Early-Stage Hormone Receptor–Positive and HER2-Negative Breast Cancer: An Analysis of the National Cancer Data Base A. Herskovic, X. Wu, P. Christos, H. Nagar, and S. Formenti; New YorkPresbyterian Hospital/Weill Cornell Medicine, New York, NY Purpose/Objective(s): The role of adjuvant radiation therapy (RT) in the treatment for early-stage hormone receptor positive and HER2 negative breast cancer in older women after breast conservation therapy remains controversial. We investigated national practice patterns and outcomes for these patients using the National Cancer Database (NCDB). Materials/Methods: Women aged 65 years and older with hormone receptor positive and HER2 negative pathologic T1-T2N0M0 measuring up to 3 cm invasive breast cancer who were treated with breast conservation and adjuvant endocrine therapy without adjuvant chemotherapy from 2006-2013 were identified and stratified by the use of adjuvant RT. Multivariable proportional hazards modelling was used to examine the association of treatment and mortality adjusting for demographic, socioeconomic and clinicopathologic factors. Results: A total of 61,395 patients with a median follow-up of 48.7 months (range 0-107) were identified. Improved overall survival was associated with younger age, facility type, income level, lower Charlson-Deyo comorbidity index, lower stage, smaller tumor size, number of nodes examined, and receipt of adjuvant RT (all P<.05). The overall 5-year survival rate was 93.0% (95% confidence interval 92.7%-93.3%) in the adjuvant RT group and 83.6% (95% confidence interval 82.5%-84.7%) in the non-adjuvant RT group (P<.0001). Conclusion: Improved survival is associated with receipt of adjuvant radiation therapy for older women with early-stage hormone receptor positive HER2 negative breast cancer who received adjuvant endocrine therapy. Author Disclosure: A. Herskovic: None. X. Wu: None. P. Christos: None. H. Nagar: None. S. Formenti: Research Grant; Regeneron, Jansseen Biotech, Eli Lilly. Speaker’s Bureau; Varian. Advisory Committee; Smith Kline. Advisory Committee; BMS, Astra Zeneca, EISAI.
2126 Impact on Lung Dose in Left Breast Radiation Therapy Patients With Deep Inspiration Breath Hold Versus Free Breathing Technique L. Vijeh, Y. Ahmed, L. Lee, and Y. Cao; Northwell Health, Lake Success, NY Purpose/Objective(s): This study evaluates lung dose for deep inspiration breath hold (DIBH) versus free breathing (FB) technique in patients with left-sided breast cancer. Materials/Methods: This is a retrospective study of 20 patients with left-sided breast cancer who underwent radiation therapy to evaluate for ipsilateral lung dose between the use of DIBH technique and FB. At the simulation, CT images were acquired with DIBH as well as FB, in two separate scans. The variation of chest motion was assessed by
2127 Practice Patterns and Outcomes for Postmastectomy Radiation After Complete Pathological Response in Stage II and IIIA Breast Cancer Patients: Analysis of the National Cancer Data Base J. Chen, X. Wu, P. Christos, D. Nori, S. Formenti, and H. Nagar; New YorkPresbyterian Hospital/Weill Cornell Medicine, New York, NY Purpose/Objective(s): In the management of breast cancer, neoadjuvant chemotherapy (NAC) allows conversion from mastectomy to breast conservation surgery in some patients, and it also provides valuable information on pathological response of the cancer to chemotherapy. However, the role of post-mastectomy radiation therapy (PMRT) is not clear following NAC, especially in the setting of a pathologic complete response (pCR). In the absence of any published prospective randomized studies, retrospective reports have attempted to provide information delineating the selection of patients that benefit from PMRT. Much of these data have come from MDACC reports, where preliminary results indicate survival benefit of PMRT in patients with stage IIIB disease, and local control benefit in stage III and possibly in T3N0 patients. In this report, we add to the available retrospective evidence regarding which patients benefit and which may be able to forego PMRT in this setting. Methods/Materials: Women with stage IIA (excluding T2N0), IIB, and IIIA breast cancer who had a complete pathological response to neoadjuvant chemotherapy (as defined by no invasive carcinoma seen in surgical pathology in breast and nodes) were identified in the NCDB from 2004 e 2013. A total of 1584 patients were identified and multivariable proportional hazards modelling was used to examine the association of treatment and mortality adjusting for demographic, socioeconomic and clinicopathologic factors. Results: A total of 1,584 patients met all inclusion criteria, with a median follow-up of 39 months. Of these, 935 (59.0%) received PMRT and 649 (41.0%) did not. In the group that received PMRT, 94.35% were alive at 3 years, compared to 93.98% in the group that did not receive PMRT (P Z 0.60). Conclusion: PMRT did not significantly impact survival in women with node-positive stage IIA, stage IIB, and stage IIIA breast cancer who had pCR after NAC, at a short median follow up of 39 months. The findings are biased by the retrospective nature of this analysis and the interplay of other variables that were not measured. Prospective randomized trials will elucidate this important issue.