- Email: [email protected]
Impact of Cardiac Sparing Techniques on Cardiac Doses for Left Breast Cancer Patients: A Multicenter Analysis
Volume 93 Number 3S Supplement 2015 Purpose/Objective(s): We report the results of our study of Intra-Operative radiation therapy (IORT) utilizing kilovoltage radiation (eBx) as a form of accelerated partial breast irradiation (APBI). The mobile nature of the eBx controller, as well as the limited shielding requirements, makes eBx a logical modality to be utilized for IORT. Materials/Methods: The study population consisted of 68 patients with 69 early-stage breast cancers enrolled in a multi-center trial utilizing eBx. Inclusion criteria include patients equal to or greater than 45 years of age, tumors equal to or less than 3 cm, tumors with infiltrating ductal or DCIS histology, and patients with uninvolved lymph nodes by frozen section at the time of surgery. All patients had an ultrasound performed at the time of surgery to verify a recommended minimum 1-cm of balloon-to-skin distance and evaluate the conformance of the balloon to the surrounding breast tissue. A pliable lead shield was placed over the chest wall before radiation treatment. Pre-loaded radiation plans for balloon inflation sizes of 40cc, 50cc, 60cc, and 70 cc were utilized. The radiation prescription dose was 20 Gy delivered to the balloon surface. Results: The mean time to deliver the radiation was 13 minutes (range 7 e 30 minutes). The total procedure time including lumpectomy, sentinel lymph node biopsy, balloon catheter placement, eBx controller calibration, radiation treatment, and closing was a mean time of 2 hour and 20 minutes (range 44 minutes e 6 hours 19 minutes). The mean balloon-to-skin distance by ultrasound for the 68 patients was 1.4 cm (range 0.7 cm e 2.8 cm). At last follow-up, overall cosmesis was rated as excellent in 88%, good in 9%, and fair in 3% of patients. Grade 1 or Grade 2 fibrosis, seroma, edema, and pain developed in 16%, 12%, 9%, and 9% of the patients respectively. There were 5 reported Grade 3 toxicities (2 infections, 1 telangiectasia, 1 nipple deformity, and 1 seroma). No Grade 4 or 5 toxicities were reported. There have been 4 total local recurrences (6%). Conclusion: IORT utilizing eBx is feasible and can be accomplished in a total procedure time of approximately 2 hours. At 5-years follow-up, eBx IORT appears to be well tolerated and have rates of local recurrence comparable to other forms of APBI. Further research on eBx and other methods of IORT is needed to establish long-term clinical efficacy and safety for patients with early-stage breast cancer. Author Disclosure: A. Dickler: Independent Contractor; iCAD/Xoft. O. Ivanov: None. A. Syed: None. S. Golder: None. G.M. Proulx: None. V. Arterberry: None. C. Cox: None. S. Kamath: None. A. Bhatnagar: None. K.M. Smorowski: None. S. Packianathan: None.
2062 Long-term Cosmetic Outcomes of 397 Patients Treated With Prone Partial-Breast Irradiation After Breast Conserving Surgery L. Di Brina,1,2 S. Shin,3 C.A. Perez,2 M.B. Fenton-Kerimian,4 G. Jozsef,2 J.K. DeWyngaert,2 and S.C. Formenti3; 1University of Florence, Department of Radiation Oncology, Florence, Italy, 2New York University School of Medicine and Langone Medical Center, Department of Radiation Oncology, New York, NY, 3New York University School of Medicine and Langone Medical Center, New York, NY, 4New York University School of Medicine, New York, NY Purpose/Objective(s): To report cosmetic outcomes of breast cancer patients treated in two clinical trials of partial breast irradiation (PBI) using prone setup. Materials/Methods: From 2000 to 2014, 397 postmenopausal patients with stage IA breast cancer were treated with prone PBI in two consecutive IRB-approved prospective trials. In the first study (nZ100), PTV was defined as a 2cm expansion of the tumor cavity and treated to 30 Gy in 5 fractions every other day. In the second study (nZ297), PTV was defined as a 1.5 cm expansion of the tumor cavity and treated to 30 Gy in 5 consecutive daily fractions. In both studies, normal tissue dose constraints to the index breast consisted of V50 < 60% and V100 < 35%. Toxicity and cosmetic outcomes were graded using the LENT/SOMA classification of late effects. Physician and patient reported cosmesis were collected.
Poster Viewing Session
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Characteristics of patients with fair/poor cosmesis were compared to those with excellent cosmesis, including ratio of tumor bed volume to breast volume, treatment technique (IMRT versus 3D-CRT), age (less or greater than 60), and time from surgery to RT (less or greater than 30 days). Features associated with fair/poor cosmesis were analyzed using both univariate and multivariate analysis. Results: IMRT was used for 199 patients (50.1%): the remaining 198 patients underwent 3D-CRT. At a median follow up of 26 months (range 0.3-111), a complete evaluation of breast cosmesis was available in 318 patients (Table 1). Maximum toxicity was one case of grade 3 asymmetry. Grade 2 toxicities included: asymmetry (3.1%), fibrosis (2.5%), retraction (1.8%), telangiectasia (1.5%), and skin thickening (1.2%). Forty one patients self-reported fair (10.7%) or poor (2.2%) cosmesis. The table summarizes the cosmetic assessment of patients and physicians. Analysis of potential predictors for cosmetic outcome demonstrated that in all 41 cases of fair/poor cosmesis all dosimetric constraints were met (mean V50 Z 50.3%; mean V100 Z 29.5%). On univariate analysis, only a ratio > 8% of tumor bed volume to breast volume was significantly associated with unacceptable cosmesis (pZ0.029). On multivariate analysis, none of the covariates analyzed reached statistical significance. Poster Viewing Abstracts 2062; Table 1 Cosmetic Results* Excellent/Good Fair Poor
Reported by Patient (nZ318)
Reported by Physician (nZ318)
277 (87.1%) 34 (10.7%) 7 (2.2%)
293 (92.2%) 24 (7.5%) 1 (0.3%)
*LENT/SOMA classification of late effects Conclusion: Favorable long term cosmetic outcomes were achieved in two prospective trials of prone PBI, whether assessed by patients or physicians. Author Disclosure: L. Di Brina: None. S. Shin: None. C.A. Perez: None. M.B. Fenton-Kerimian: None. G. Jozsef: None. J. DeWyngaert: None. S. Formenti: None.
2063 Impact of Cardiac Sparing Techniques on Cardiac Doses for Left Breast Cancer Patients: A Multicenter Analysis J.M. Moran,1 M. Feng,1 R. Marsh,2 K.A. Griffith,1 L. Benedetti,3 I.S. Grills,4 E.M. Walker,5 C. Fraser,5 S. Raymond,6 J.P. Blauser,7 B.T. Gielda,7 F.A. Vicini,8 M. Wilson,8 D.A. Dryden,9 K. Parent,9 A. Ewald,10 M.M. Matuszak,1 R. Jagsi,1 M. Grubb,2 and L.J. Pierce1; 1 University of Michigan, Ann Arbor, MI, 2Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 3William Beaumont Health System, Royal Oak, MI, 4Beaumont Health System, Royal Oak, MI, 5 Henry Ford Health System, Detroit, MI, 6Munson Medical Center, Traverse City, MI, 7Lakeland Regional Medical Center, Saint Joseph, MI, 8 21st Century Oncology, Farmington Hills, MI, 9McLaren Northern Michigan, Petoskey, MI, 10McLaren Cancer Institute - Flint, Flint, MI Purpose/Objective(s): Due to potential long-term cardiac toxicity following breast RT, minimizing cardiac dose has been increasingly prioritized. Techniques such as use of heart blocks or deep-inspiration breath hold (DIBH) can decrease cardiac dose. Clinical tradeoffs between cardiac sparing and target coverage can also be made. We assessed the effect of treatment technique choices on cardiac and breast doses in 8 institutions within a quality collaborative (Michigan Radiation Oncology Quality Consortium, MROQC). Materials/Methods: With IRB approval, DICOM-RT data, motion management information, and treatment technique were submitted for central review and evaluated in 104 patients with left breast cancer, randomly selected within strata for nodal treatment and motion management. The breast, whole heart, and left anterior descending artery (LAD) were contoured at the coordinating center for consistency. Target coverage and
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mean and max doses to the heart and LAD were analyzed for the complete treatment course and compared using the Wilcoxon rank-sum test. Results: Dose prescriptions for the breast varied from 40-50.6 Gy. Ninety percent of pts had a boost of 8-16 Gy. Forty-one percent were treated using DIBH. Sixty-seven percent had heart blocks. Twenty-one percent received nodal RT. Treatment techniques were 3D (74%) or IMRT (26%), with IMRT being defined as any static or rotational technique with at least 1 beam delivering 5 segments. The table shows cardiac and breast doses by DIBH, heart block, treatment technique, and nodal targeting. Max heart and LAD doses were significantly lower when DIBH was used. In contrast, whole heart and LAD doses were not significantly different in pts treated with or without heart blocks. Pts treated with IMRT had higher max heart and LAD doses when compared to 3D RT. The dose covering 95% of the breast (D95) was not different in pts with or without DIBH but was significantly lower in pts with heart blocks. Pts with nodal RT had higher breast D95. Conclusion: Cardiac doses are highly variable even within a quality collaborative. With DIBH, max dose to the heart was 60% lower with breast coverage maintained. The use of heart blocks was associated with reduced breast coverage but not lower cardiac dose. MROQC members will use these data to guide future heart dose reductions. Further comparisons of cardiac doses are warranted of 3D vs IMRT techniques. Supported by the Breast Cancer Research Foundation and BCBS of Michigan
Research Foundation. Acting CEO and COO; University of Michigan. Vice Provost for Academic Affairs; University of Michigan.
Poster Viewing Abstracts 2063; Table 1 Heart e Max Dose (Gy) *p Yes vs No
Technique DIBHYZ43; NZ61 Heart Block YZ70; NZ34 Technique 3D (77); IMRT(27) Nodal RTYZ22; NZ82
LAD e Max Dose (Gy) *p Yes vs No
17.8 vs 45.8 <0.001 38.9 vs 43.50.32
10.3 vs 39.1 <0.001 18.3 vs 36.8 0.22
36.4 vs 46.50.01
16.2 vs 41.8 0.02
44.1 vs 39.20.19
21.4 vs 21.3 0.27
Breast D95 (Gy) *p Yes vs No 36.5 vs 36.70.47 35.9 vs 40.40.03 36.5 vs 41.70.13 39.6 vs 36.80.05
*Medians reported Author Disclosure: J.M. Moran: Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, Varian Medical Systems. Vice Chair of committee on Therapy Physics; AAPM. M. Feng: Employee; University of Michigan. Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, Celgene. Honoraria; Medivation/Astellas, Genoma Dx, Nanostring, Myriad. Patent/License Fees/Copyright; PFS Genomics for Radiotype Dx. Chair; RTOG GU Translational Program. Co-chair; IHE-RO Clinical Advisory subcommittee. Panel member; NCCN pancreatic adenocarcinoma. R. Marsh: Research Grant; Blue Cross Blue Shield of Michigan. K.A. Griffith: Research Grant; Blue Cross Blue Shield of Michigan. L. Benedetti: None. I.S. Grills: Research Grant; Elekta Collaborative Lung Research Group. Stock; Greater Michigan Gamma Knife. Member of board of directors; Greater Michigan Gamma Knife. E.M. Walker: ACR appropriateness criteria expert panel member; ACR. NRB Breast working group; NRB. NRG health disparities working group member; NRG. RTOG Foundation advisory board member; RTOG. C. Fraser: None. S. Raymond: None. J.P. Blauser: None. B.T. Gielda: None. F.A. Vicini: None. M. Wilson: Chief Investigator; Breast Thermography Research. Cancer Physician Liaison; St. Joseph Mercy Oakland. Member of AAPM Task Group 109 Code of Ethics; AAPM. D.A. Dryden: Physics Proctor; Physics Proctor for Bard Urology, LDR Prostate Seed implants and New Product Research. K. Parent: None. A. Ewald: None. M.M. Matuszak: Research Grant; Blue Cross Blue Shield of Michigan, Varian Medical Systems. R. Jagsi: Research Grant; Blue Cross Blue Shield of Michigan, Greenwall Foundation, NIH/NCI. Provision of drug & distribution for clinical trial not related to this one; AbbVie. Ethics Committee Chair; ASCO. Medical Advisory Board; Eviti. M. Grubb: Research Grant; Blue Cross Blue Shield of Michigan. L.J. Pierce: Employee; University of Michigan. Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer
2064 Radiation Lumpectomy Boost and Acute Treatment Toxicities in Patients With or Without Reduction Mammoplasty as Part of Breast Conserving Treatment J.Y. Lin,1 R. Bluebond-Langner,2 E. Choi,3 S. Cheston,4 E.M. Nichols,4 R.J. Cohen,5 S.M. Bentzen,4 C. Drogula,6 S. Kesmodel,6 E. Bellavance,6 P. Rosenblatt,7 K. Tkaczuk,7 S. Slezak,2 and S.J. Feigenberg4; 1University of Maryland Medical Center, Baltimore, MD, 2Department of Plastic Surgery, University of Maryland School of Medicine, Baltimore, MD, 3 Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, 4University of Maryland School of Medicine, Baltimore, MD, 5Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, 6Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, 7Department of Medicine, University of Maryland School of Medicine, Baltimore, MD Purpose/Objective(s): Reduction mammoplasty (RM) at time of breast conserving surgery (BCS) is an increasingly popular option to improve cosmesis in women with large-volume breasts. The procedure may reduce redundant breast folds and decrease the rate of skin-related complications from whole breast radiation therapy (WBRT). However, the additional surgery may obscure the lumpectomy cavity (LC) and hinder the radiation oncologists’ ability to deliver a boost following WBRT. We investigated the impact of the RM on boost delivery and acute radiation side effects. Materials/Methods: We retrospectively reviewed the charts of 452 women who had BCS followed by WBRT at an urban university or its community practices from January 2012 to December 2014. Acute toxicity was scored via the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0, focusing on grade 3 side effects. The second endpoint was to determine the prescription of LC boost. With an IRB-approved study, tested parameters included age, race, body mass index, menopausal status, multi-focal disease, stage, tumor grade, receptor status, chemotherapy administered, pathologic specimen volume, radiation treatment modality, fractionation, use of boost, elective nodal irradiation, and whole breast planning treatment volume (PTV). Student’s t-tests, Pearson’s chi-square tests, multivariate logistic regression, and MannWhitney U-test were utilized. Results: Thirty-four of 452 (8%) patients had a RM at the time of BCS, where a larger volume of tissue was removed (205.9 gm vs 35 gm in patients without RM, PZ0.0001). A boost was used less often in RM patients 11/34 (32%) compared to 311/413 patients without RM (75%), even after adjusting for age, clinical stage, location, tumor grade, receptor status, or chemotherapy, PZ0.000002, ORZ0.11. Few grade 3 toxicities were observed: 0% in RM patients (95% confidence interval [CI]: 0-10%) vs 2.6% (95% CI: 1.5-4.7%). Similar narcotic use (5-6%) was seen in both groups, PZ0.70. RM patients were significantly more likely to have neoadjuvant chemotherapy, stage III-IV or multifocal disease, higher BMI and conventional fractionation (P<0.05). No significant differences in age, grade, race, hormone status, chemotherapy use, or WBRT delivery technique were seen. PTVs were available for 65% of the patients with the subgroup analysis revealing similar volumes (PZ0.39). Conclusion: The use of RM was associated with less frequent use of boosts, which could decrease local control for select patients. No significant differences in acute grade 3 toxicities were seen between patients who received RM and those who did not; however, the result is not surprising given the similar breast volumes. Additional investigation is needed to delineate LCs in patients undergoing RM to increase the use of tumor bed boosts. Author Disclosure: J.Y. Lin: None. R. Bluebond-Langner: None. E. Choi: None. S. Cheston: None. E.M. Nichols: None. R.J. Cohen: None. S.M. Bentzen: None. C. Drogula: None. S. Kesmodel: None. E. Bellavance: None. P. Rosenblatt: None. K. Tkaczuk: None. S. Slezak: None. S.J. Feigenberg: None.
2062 Long-term Cosmetic Outcomes of 397 Patients Treated With Prone Partial-Breast Irradiation After Breast Conserving Surgery L. Di Brina,1,2 S. Shin,3 C.A. Perez,2 M.B. Fenton-Kerimian,4 G. Jozsef,2 J.K. DeWyngaert,2 and S.C. Formenti3; 1University of Florence, Department of Radiation Oncology, Florence, Italy, 2New York University School of Medicine and Langone Medical Center, Department of Radiation Oncology, New York, NY, 3New York University School of Medicine and Langone Medical Center, New York, NY, 4New York University School of Medicine, New York, NY Purpose/Objective(s): To report cosmetic outcomes of breast cancer patients treated in two clinical trials of partial breast irradiation (PBI) using prone setup. Materials/Methods: From 2000 to 2014, 397 postmenopausal patients with stage IA breast cancer were treated with prone PBI in two consecutive IRB-approved prospective trials. In the first study (nZ100), PTV was defined as a 2cm expansion of the tumor cavity and treated to 30 Gy in 5 fractions every other day. In the second study (nZ297), PTV was defined as a 1.5 cm expansion of the tumor cavity and treated to 30 Gy in 5 consecutive daily fractions. In both studies, normal tissue dose constraints to the index breast consisted of V50 < 60% and V100 < 35%. Toxicity and cosmetic outcomes were graded using the LENT/SOMA classification of late effects. Physician and patient reported cosmesis were collected.
Poster Viewing Session
E25
Characteristics of patients with fair/poor cosmesis were compared to those with excellent cosmesis, including ratio of tumor bed volume to breast volume, treatment technique (IMRT versus 3D-CRT), age (less or greater than 60), and time from surgery to RT (less or greater than 30 days). Features associated with fair/poor cosmesis were analyzed using both univariate and multivariate analysis. Results: IMRT was used for 199 patients (50.1%): the remaining 198 patients underwent 3D-CRT. At a median follow up of 26 months (range 0.3-111), a complete evaluation of breast cosmesis was available in 318 patients (Table 1). Maximum toxicity was one case of grade 3 asymmetry. Grade 2 toxicities included: asymmetry (3.1%), fibrosis (2.5%), retraction (1.8%), telangiectasia (1.5%), and skin thickening (1.2%). Forty one patients self-reported fair (10.7%) or poor (2.2%) cosmesis. The table summarizes the cosmetic assessment of patients and physicians. Analysis of potential predictors for cosmetic outcome demonstrated that in all 41 cases of fair/poor cosmesis all dosimetric constraints were met (mean V50 Z 50.3%; mean V100 Z 29.5%). On univariate analysis, only a ratio > 8% of tumor bed volume to breast volume was significantly associated with unacceptable cosmesis (pZ0.029). On multivariate analysis, none of the covariates analyzed reached statistical significance. Poster Viewing Abstracts 2062; Table 1 Cosmetic Results* Excellent/Good Fair Poor
Reported by Patient (nZ318)
Reported by Physician (nZ318)
277 (87.1%) 34 (10.7%) 7 (2.2%)
293 (92.2%) 24 (7.5%) 1 (0.3%)
*LENT/SOMA classification of late effects Conclusion: Favorable long term cosmetic outcomes were achieved in two prospective trials of prone PBI, whether assessed by patients or physicians. Author Disclosure: L. Di Brina: None. S. Shin: None. C.A. Perez: None. M.B. Fenton-Kerimian: None. G. Jozsef: None. J. DeWyngaert: None. S. Formenti: None.
2063 Impact of Cardiac Sparing Techniques on Cardiac Doses for Left Breast Cancer Patients: A Multicenter Analysis J.M. Moran,1 M. Feng,1 R. Marsh,2 K.A. Griffith,1 L. Benedetti,3 I.S. Grills,4 E.M. Walker,5 C. Fraser,5 S. Raymond,6 J.P. Blauser,7 B.T. Gielda,7 F.A. Vicini,8 M. Wilson,8 D.A. Dryden,9 K. Parent,9 A. Ewald,10 M.M. Matuszak,1 R. Jagsi,1 M. Grubb,2 and L.J. Pierce1; 1 University of Michigan, Ann Arbor, MI, 2Department of Radiation Oncology, University of Michigan, Ann Arbor, MI, 3William Beaumont Health System, Royal Oak, MI, 4Beaumont Health System, Royal Oak, MI, 5 Henry Ford Health System, Detroit, MI, 6Munson Medical Center, Traverse City, MI, 7Lakeland Regional Medical Center, Saint Joseph, MI, 8 21st Century Oncology, Farmington Hills, MI, 9McLaren Northern Michigan, Petoskey, MI, 10McLaren Cancer Institute - Flint, Flint, MI Purpose/Objective(s): Due to potential long-term cardiac toxicity following breast RT, minimizing cardiac dose has been increasingly prioritized. Techniques such as use of heart blocks or deep-inspiration breath hold (DIBH) can decrease cardiac dose. Clinical tradeoffs between cardiac sparing and target coverage can also be made. We assessed the effect of treatment technique choices on cardiac and breast doses in 8 institutions within a quality collaborative (Michigan Radiation Oncology Quality Consortium, MROQC). Materials/Methods: With IRB approval, DICOM-RT data, motion management information, and treatment technique were submitted for central review and evaluated in 104 patients with left breast cancer, randomly selected within strata for nodal treatment and motion management. The breast, whole heart, and left anterior descending artery (LAD) were contoured at the coordinating center for consistency. Target coverage and
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mean and max doses to the heart and LAD were analyzed for the complete treatment course and compared using the Wilcoxon rank-sum test. Results: Dose prescriptions for the breast varied from 40-50.6 Gy. Ninety percent of pts had a boost of 8-16 Gy. Forty-one percent were treated using DIBH. Sixty-seven percent had heart blocks. Twenty-one percent received nodal RT. Treatment techniques were 3D (74%) or IMRT (26%), with IMRT being defined as any static or rotational technique with at least 1 beam delivering 5 segments. The table shows cardiac and breast doses by DIBH, heart block, treatment technique, and nodal targeting. Max heart and LAD doses were significantly lower when DIBH was used. In contrast, whole heart and LAD doses were not significantly different in pts treated with or without heart blocks. Pts treated with IMRT had higher max heart and LAD doses when compared to 3D RT. The dose covering 95% of the breast (D95) was not different in pts with or without DIBH but was significantly lower in pts with heart blocks. Pts with nodal RT had higher breast D95. Conclusion: Cardiac doses are highly variable even within a quality collaborative. With DIBH, max dose to the heart was 60% lower with breast coverage maintained. The use of heart blocks was associated with reduced breast coverage but not lower cardiac dose. MROQC members will use these data to guide future heart dose reductions. Further comparisons of cardiac doses are warranted of 3D vs IMRT techniques. Supported by the Breast Cancer Research Foundation and BCBS of Michigan
Research Foundation. Acting CEO and COO; University of Michigan. Vice Provost for Academic Affairs; University of Michigan.
Poster Viewing Abstracts 2063; Table 1 Heart e Max Dose (Gy) *p Yes vs No
Technique DIBHYZ43; NZ61 Heart Block YZ70; NZ34 Technique 3D (77); IMRT(27) Nodal RTYZ22; NZ82
LAD e Max Dose (Gy) *p Yes vs No
17.8 vs 45.8 <0.001 38.9 vs 43.50.32
10.3 vs 39.1 <0.001 18.3 vs 36.8 0.22
36.4 vs 46.50.01
16.2 vs 41.8 0.02
44.1 vs 39.20.19
21.4 vs 21.3 0.27
Breast D95 (Gy) *p Yes vs No 36.5 vs 36.70.47 35.9 vs 40.40.03 36.5 vs 41.70.13 39.6 vs 36.80.05
*Medians reported Author Disclosure: J.M. Moran: Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, Varian Medical Systems. Vice Chair of committee on Therapy Physics; AAPM. M. Feng: Employee; University of Michigan. Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer Research Foundation, Celgene. Honoraria; Medivation/Astellas, Genoma Dx, Nanostring, Myriad. Patent/License Fees/Copyright; PFS Genomics for Radiotype Dx. Chair; RTOG GU Translational Program. Co-chair; IHE-RO Clinical Advisory subcommittee. Panel member; NCCN pancreatic adenocarcinoma. R. Marsh: Research Grant; Blue Cross Blue Shield of Michigan. K.A. Griffith: Research Grant; Blue Cross Blue Shield of Michigan. L. Benedetti: None. I.S. Grills: Research Grant; Elekta Collaborative Lung Research Group. Stock; Greater Michigan Gamma Knife. Member of board of directors; Greater Michigan Gamma Knife. E.M. Walker: ACR appropriateness criteria expert panel member; ACR. NRB Breast working group; NRB. NRG health disparities working group member; NRG. RTOG Foundation advisory board member; RTOG. C. Fraser: None. S. Raymond: None. J.P. Blauser: None. B.T. Gielda: None. F.A. Vicini: None. M. Wilson: Chief Investigator; Breast Thermography Research. Cancer Physician Liaison; St. Joseph Mercy Oakland. Member of AAPM Task Group 109 Code of Ethics; AAPM. D.A. Dryden: Physics Proctor; Physics Proctor for Bard Urology, LDR Prostate Seed implants and New Product Research. K. Parent: None. A. Ewald: None. M.M. Matuszak: Research Grant; Blue Cross Blue Shield of Michigan, Varian Medical Systems. R. Jagsi: Research Grant; Blue Cross Blue Shield of Michigan, Greenwall Foundation, NIH/NCI. Provision of drug & distribution for clinical trial not related to this one; AbbVie. Ethics Committee Chair; ASCO. Medical Advisory Board; Eviti. M. Grubb: Research Grant; Blue Cross Blue Shield of Michigan. L.J. Pierce: Employee; University of Michigan. Research Grant; Blue Cross Blue Shield of Michigan, Breast Cancer
2064 Radiation Lumpectomy Boost and Acute Treatment Toxicities in Patients With or Without Reduction Mammoplasty as Part of Breast Conserving Treatment J.Y. Lin,1 R. Bluebond-Langner,2 E. Choi,3 S. Cheston,4 E.M. Nichols,4 R.J. Cohen,5 S.M. Bentzen,4 C. Drogula,6 S. Kesmodel,6 E. Bellavance,6 P. Rosenblatt,7 K. Tkaczuk,7 S. Slezak,2 and S.J. Feigenberg4; 1University of Maryland Medical Center, Baltimore, MD, 2Department of Plastic Surgery, University of Maryland School of Medicine, Baltimore, MD, 3 Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, 4University of Maryland School of Medicine, Baltimore, MD, 5Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD, 6Department of Surgery, University of Maryland School of Medicine, Baltimore, MD, 7Department of Medicine, University of Maryland School of Medicine, Baltimore, MD Purpose/Objective(s): Reduction mammoplasty (RM) at time of breast conserving surgery (BCS) is an increasingly popular option to improve cosmesis in women with large-volume breasts. The procedure may reduce redundant breast folds and decrease the rate of skin-related complications from whole breast radiation therapy (WBRT). However, the additional surgery may obscure the lumpectomy cavity (LC) and hinder the radiation oncologists’ ability to deliver a boost following WBRT. We investigated the impact of the RM on boost delivery and acute radiation side effects. Materials/Methods: We retrospectively reviewed the charts of 452 women who had BCS followed by WBRT at an urban university or its community practices from January 2012 to December 2014. Acute toxicity was scored via the National Cancer Institute Common Terminology Criteria for Adverse Events version 4.0, focusing on grade 3 side effects. The second endpoint was to determine the prescription of LC boost. With an IRB-approved study, tested parameters included age, race, body mass index, menopausal status, multi-focal disease, stage, tumor grade, receptor status, chemotherapy administered, pathologic specimen volume, radiation treatment modality, fractionation, use of boost, elective nodal irradiation, and whole breast planning treatment volume (PTV). Student’s t-tests, Pearson’s chi-square tests, multivariate logistic regression, and MannWhitney U-test were utilized. Results: Thirty-four of 452 (8%) patients had a RM at the time of BCS, where a larger volume of tissue was removed (205.9 gm vs 35 gm in patients without RM, PZ0.0001). A boost was used less often in RM patients 11/34 (32%) compared to 311/413 patients without RM (75%), even after adjusting for age, clinical stage, location, tumor grade, receptor status, or chemotherapy, PZ0.000002, ORZ0.11. Few grade 3 toxicities were observed: 0% in RM patients (95% confidence interval [CI]: 0-10%) vs 2.6% (95% CI: 1.5-4.7%). Similar narcotic use (5-6%) was seen in both groups, PZ0.70. RM patients were significantly more likely to have neoadjuvant chemotherapy, stage III-IV or multifocal disease, higher BMI and conventional fractionation (P<0.05). No significant differences in age, grade, race, hormone status, chemotherapy use, or WBRT delivery technique were seen. PTVs were available for 65% of the patients with the subgroup analysis revealing similar volumes (PZ0.39). Conclusion: The use of RM was associated with less frequent use of boosts, which could decrease local control for select patients. No significant differences in acute grade 3 toxicities were seen between patients who received RM and those who did not; however, the result is not surprising given the similar breast volumes. Additional investigation is needed to delineate LCs in patients undergoing RM to increase the use of tumor bed boosts. Author Disclosure: J.Y. Lin: None. R. Bluebond-Langner: None. E. Choi: None. S. Cheston: None. E.M. Nichols: None. R.J. Cohen: None. S.M. Bentzen: None. C. Drogula: None. S. Kesmodel: None. E. Bellavance: None. P. Rosenblatt: None. K. Tkaczuk: None. S. Slezak: None. S.J. Feigenberg: None.