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Higher Mean Heart Dose With Brachytherapy Based Accelerated Partial-Breast Irradiation Compared to External Beam Whole-Breast Irradiation With Breath-Hold in Women With Left-Sided Tumors
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International Journal of Radiation Oncology Biology Physics
without replacement using a propensity score algorithm for age, T stage, systemic therapy use, bra cup size, type of boost (photon vs electron), grade, lymphovascular invasion, and ER/PR status. Adverse events during RT were considered acute, while events >1.5months after RT were considered late. All side effects were graded based on CTCAE v3. Patient reported cosmesis was scored using the Harvard scale (1 Z excellent, 2 Z good, 3 Z fair, 4 Z poor). Kaplan-Meier curves and Cox proportional hazard models with robust standard errors were used to estimate local control (LC). Proportions were evaluated using Mantel-Haenszel tests to account for the effect of matching. Results: Median follow-up was 52 months (range, 3.5e130). Median age was 56 years (range, 31e88). The HRT patients included 19% Tis, 65% T1, and 16% T2 tumors; 86% were node negative. Eighty percent had negative margins, 18% had close (>0 and <2 mm) margins, and 2% had positive margins. The majority of pts received systemic therapy (45% endocrine therapy, 10% chemotherapy, and 22% both). We matched 241 of the 247 HRT pts to 482 CRT pts with no significant differences between groups except more unknown grade in CRT group. Eight-year LC was 97.5% for HRT versus 96.6% in the CRT group (P Z .78). There was no significant difference in any grade acute skin erythema in HRT versus CRT (91.3% vs 90.9%, P Z .89). Grade 2+ acute side effects were more frequent in CRT versus HRT (47.1% vs 18.7%, P < 0.01). There was no difference in any grade late side effects experienced in the CRT versus HRT group (47.7% vs 41.5%, P Z .12); 79% of late side effects in both groups were grade 1. The most common late side effects were edema, hyperpigmentation, erythema, and fibrosis. Mean pt reported cosmesis scores were similar at 3 years for HRT versus CRT (1.9 vs 1.9). Conclusion: The 4-week course of hypofractionated whole-breast radiation with incorporated boost was associated with excellent long-term LC, less acute side effects, similar cosmesis, and late side effects compared to conventional fractionation with sequential boost. Author Disclosure: L. Wang: None. C.T. Murphy: None. E. Handorf: None. G.M. Freedman: None. M.E. Johnson: None. T. Shaikh: None. S.B. Hayes: None. R.J. Bleicher: None. L. Goldstein: None. P.R. Anderson: None.
surgery (BCS) by a cooperative group of institutions. Single entry brachytherapy device results have been reported, but this is the first report with a large cohort of patients treated by MIB. Materials/Methods: Five institutions with extensive experience in treating select breast cancers with MIB contributed their experience to this retrospective clinical study. From March 1997 to August 2013, 1,372 patients with Stage Tis, T1e2, N0, and N1 (<3 positive nodes without extracapsular extension) underwent BCS with clear margins and pathologic size <3 cm, followed by APBI using interstitial multicatheter brachytherapy. All patients who had documentation of toxicity and cosmesis comprise this report, with 800 in the cosmesis evaluation alone. Mean age was 60.4 +/- 10.8 years. All patients received 32e34 Gy in 8e10 fractions over 4e5 days with high-dose-rate or 45 Gy over 3e5 days low-dose-rate Iridium-192 seeds. One hundred thirty-five patients (17.1%) received chemotherapy and 503 (68.7%) endocrine therapy. Cosmesis, toxicities, and subsequent mastectomy rates (MR) were evaluated at yearly intervals. Results: The overall median follow-up was 82 months (range, 1e245 months); however, the median follow-up for the assessment of toxicities was 48 months. For cosmesis, 612 of the 800 patients had at least 2 years of follow-up. Only 79 had follow-up of 1 year or less. Subsequent mastectomy rates were 0% (<1 year), 1% (1e2 years), 2% (2e5 years), and 2% (>6 years). Results are given in the Table below. Conclusion: This cooperative multi-institutional study is the largest published report of toxicity and cosmetic outcomes of patients treated by MIB. This radiation therapy method to complete breast conserving therapy was associated with excellent cosmetic outcomes and low-toxicity rates that change over time but remain acceptable beyond 5 years. Author Disclosure: R.R. Kuske: Consultant; Elekta. Minor Stock Option; Cianna. M. Kamrava: None. P.Y. Chen: None. J.K. Hayes: None. B.M. Anderson: None. C.A. Quiet: None. J. Wang: None. D. Veruttipong: None. M. Snyder: None. D. Demanes: None.
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Short and Long-term Toxicity and Cosmesis After Interstitial Multicatheter Brachytherapy for Accelerated Partial-Breast Irradiation: A Multi-institutional Study R.R. Kuske,1 M. Kamrava,2 P.Y. Chen,3 J.K. Hayes,4 B.M. Anderson,5 C.A. Quiet,6 J. Wang,2 D. Veruttipong,7 M. Snyder,1 and D.J. Demanes7; 1 Arizona Breast Cancer Specialists, Scottsdale, AZ, 2UCLA, Los Angeles, CA, 3Beaumont Health System, Royal Oak, MI, 4Gamma West Cancer Services, Salt Lake City, UT, 5University of Wisconsin Office of CME, Madison, WI, 6Arizona Breast Cancer Specialists, Arizona Center for Cancer Care, Phoenix, AZ, 7University of California, Los Angeles, Los Angeles, CA
Higher Mean Heart Dose With Brachytherapy Based Accelerated Partial-Breast Irradiation Compared to External Beam Whole-Breast Irradiation With Breath-Hold in Women With Left-Sided Tumors E. Holliday,1 S.M. Kirsner,2 H.D. Thames,3 B. Mason,4 C. Nelson,5 and E.S. Bloom3; 1MD Anderson Cancer Center, Houston, TX, 2The University of Texas MD Anderson Cancer Center, Houston, TX, 3MD Anderson Cancer Center, Houston, TX, 4University of Texas MD Anderson Cancer Center, Houston, TX, 5The University of Texas MD Anderson Cancer Center, San Antonio, TX
Purpose/Objective(s): To report toxicity and cosmesis outcomes after multicatheter interstitial brachytherapy (MIB) for accelerated partialbreast irradiation (APBI) for select breast cancers after breast conserving
Oral Scientific Abstracts 133; Table Toxicity Cosmesis: Fair/Poor (800) Fibrosis N (502) Grade 2/3/4 Telangiectasia N (503) Grade 1/2 Infection N (597) Grade 2/3/4 Fat Necrosis N (452) Grade 2/3
Eval at <1 yr
Eval at 1e2 yrs
Eval at 2e5 yrs
Eval at >6yrs
1%/1%
3%/0%
7%/2%
8%/1%
79 9%/0% 100 4%/0% 158 1%/0% 136 0%
67 18%/0% 39 31%/5% 18 11%/0% 28 0%/4%
238 8%/0.4% 248 15%/3% 190 14%/0% 197 2%/0%
118 12%/0% 116 7%/3% 41 18%/0% 91 1%/0%
Purpose/Objective(s): Accelerated partial-breast irradiation (APBI) is utilized as an alternative to whole-breast irradiation (WBI) for selected low-risk breast cancer (BCa) patients. During APBI treatment planning, dose is minimized to the skin and ribs; however, for left-sided tumors, dose to the heart is also a concern. We present a comparison of mean heart and coronary artery doses between patients treated with APBI and patients treated with WBI utilizing a deep inspiration breath-hold technique (DIBH-WBI). Materials/Methods: One hundred patients with left-sided, early-stage BCa were identified. Fifty underwent single-entry catheter-based APBI with a Contura (N Z 11) or SAVI (N Z 39) device, and 50 underwent DIBH-WBI. Four targets were delineated: heart, left anterior descending/ interventricular branch (LAD/IVB), left main (LM) and right coronary artery (RCA). Mean SD doses to the heart and coronary vessels were calculated from APBI treatment plans (34 Gy in 3.4 Gy twice daily fractions). The same doses were calculated for the DIBH-WBI cohort utilizing 4 plans generated from the same set up: 50 Gy in 25 fractions (50/25), 50/25 + 10/5 boost, 40.05/15, and 40.05/15 + 10/5 boost. Biologically effective doses (BED) were calculated using an assumed repair halftime of 4 h and a/b ratio of 3 Gy.
Volume 93 Number 3S Supplement 2015 Results: Mean doses to the heart were higher (P < .0001) for APBI (2.23 0.91 Gy) than for BH-WBI plans (0.67 0.14 Gy for 50/25, 0.90 0.36 Gy for 50/25 + boost, 0.53 0.11 Gy for 40/15, 0.77 0.35 Gy for 40/15 + boost). BEDs to the heart were 0.67 0.15 (50/25), 1.1 0.39 (50/25 + boost), 0.54 0.12 (40/15), and 0.96 0.37 Gy (40/15 + boost), each significantly lower than for APBI (2.50 1.13 Gy, P < .0001). Statistical comparisons of APBI with BH-WBI were similar for mean doses and BEDs: differences in mean doses and BEDs to LAD/IVB, LM, and RCA were not as large, but (with the exception of LAD/IVB for 50/25 + boost P Z .0245, and 40/15 + boost P Z .0023) still highly significant (P < .0001). Conclusion: In our cohort of women with left-sided BCa, APBI resulted in significantly higher mean dose and BED to the heart and coronary vessels when compared to WBI utilizing a breath-hold technique. Long-term assessment of late effects in these tissues will be required to determine whether these differences are clinically significant. Author Disclosure: E. Holliday: None. S.M. Kirsner: None. H.D. Thames: None. B. Mason: None. C. Nelson: None. E. Bloom: None.
135 Stereotactic Body Radiation Therapy for Early-Stage Breast Cancer Using a Robotic Linear Accelerator J.A. Haas,1 S.R. Blacksburg,1 F. Monteleone,1 D. Catell,2 A.E. Gittleman,2 O. Clancey,1 H. Staszewski,1 W. Reed,1 M. Giambona,1 A. Sanchez,1 D. Accordino,1 S. Lowery,3 and M.R. Witten1; 1Winthrop-University Hospital, Mineola, NY, 2Winthrop-University Hospital, Mineola, NY, 3 Winthrop-University Hospital, Mineola, NY Purpose/Objective(s): Standard radiation therapy for patients with breast cancer desiring breast conservation typically consists of lumpectomy followed by radiation. Radiation can either be delivered to the whole-breast or to part of the breast. Whole-breast radiation is typically given daily for 3e6 weeks depending on the dose/fractionation scheme. When partial-breast irradiation is given, often an implanted catheter is used to deliver a conformal dose of radiation to the lumpectomy cavity in an accelerated manner over one week. In properly selected patients, the results for partial-breast irradiation appear comparable to results for conventional whole-breast radiation. We examined the safety and efficacy of using an accelerated dose/fractionation schedule with a robotic linear accelerator for selected patients with early-stage breast cancer after lumpectomy. We reported on our technique and early results. Materials/Methods: Twenty-six consecutive patients with early-stage breast cancer were enrolled on an IRB approved breast protocol. Eligibility included Stage 0/I/II (<3 cm) Age >45, margins negative. One patient had fiducial markers placed by the surgeon. The other 25 patients had fiducial markers placed by the treating radiation oncologist using image guidance on a CT simulator with coordinate placement determined by the physics/dosimetry staff for optimal location. Patients were immobilized either using a thermoplastic cast with a hole removed around the areola to allow for reproducibility daily or with an alpha cradle to allow the breast to remain in its natural position. All patients received a dose of 3,000 cGy in 5 fractions of 600 cGy each given on five consecutive days. The median number of beams was 86. The median prescription isodose line was 71%. This isodose was chosen to allow for a more rapid fall of dose beyond the target volume to more accurately emulate HDR treatment. Results: With a median follow-up of 27 months, (range, 3e48 months) all 26 patients (100%) remain locally controlled with no evidence of disease following treatment. RTOG Grade 1 dry skin desquamation occurred in 1 of 26 patients. The cosmesis was good-excellent in all 26 patients using the Harvard cosmesis scale. Conclusion: Stereotactic body radiosurgery for early-stage breast cancer using a robotic linear accelerator is very well tolerated and efficacious for selected patients desiring breast conservation after lumpectomy. More
Oral Scientific Sessions
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accrual and further follow-up will be required to see if these results remain durable. Author Disclosure: J.A. Haas: Honoraria; Accuray. S.R. Blacksburg: Speaker’s Bureau; Bayer. F. Monteleone: None. D. Catell: None. A.E. Gittleman: None. O. Clancey: None. H. Staszewski: None. W. Reed: None. M. Giambona: None. A. Sanchez: None. D. Accordino: None. S. Lowery: None. M.R. Witten: None.
136 The Impact of Dynamic Changes to a Bone Metastases Pathway in a Large Integrated National Cancer Institute Designated Comprehensive Cancer Center Network B.J. Gebhardt, M.S. Rajagopalan, B.S. Gill, D.E. Heron, S.M. Rakfal, J.C. Flickinger, Sr, and S. Beriwal; University of Pittsburgh Cancer Institute, Pittsburgh, PA Purpose/Objective(s): Multiple studies suggest equivalent pain relief from bone metastases following radiation therapy with either 10 fraction regimens or shorter courses. Although ASTRO evidence-based guidelines and the Choosing WiselyÒ campaign recommend single-fraction treatments and caution against routinely using extended (>10 fraction) courses, recent publications report single-fraction utilization rates below 5%. We evaluated the impact of our bone metastasis clinical pathway on the adoption of short-course palliative radiation therapy in a large, integrated radiation oncology network. Materials/Methods: In 2003, we implemented a clinical pathway for the management of bone metastases with palliative radiation therapy. In 2009, we required the entry of management decisions into an online tool that records pathway choices and subjects off-pathway choices to peer-review. The pathway specified 1 or 5 fractions for symptomatic bone metastases with the option of 10e14 fractions for certain clinical situations. In 2014, the pathway was modified to encourage single-fraction treatment, and the use of >10 fractions was considered off-pathway. Data were obtained from 16 integrated sites (4 central academic, 12 community locations) from 2003 through 2014. Multivariate logistic regression was conducted to establish factors associated with treatment with a single fraction and with >10 fractions. Results: In this study, 12,678 unique courses were delivered with 61% delivered in the community and 39% in academic locations. From 2003e2008, the single-fraction utilization rate was 7.6%. This increased to 10.9% from 2009e2013 and to 15.8% in 2014. Compared to 2003e2008, the odds-ratios for single-fraction utilization were 1.59 (95% CI: 1.39e1.81) and 2.58 (95% CI: 2.11e3.15), for 2009e2013 and 2014, respectively. Academic physicians were significantly more likely to treat with a single-fraction (OR: 5.00, 95% CI: 4.38e5.71). Utilization of >10 fraction regimens decreased from 18.6% from 2003e2008 to 15.2% from 2009e2013 and to 9.7% in 2014, predominantly from rates in the community physician subset changing from 24.3% to 21.2% to 12.7%, respectively (P < .0001). Conclusion: This study demonstrates the transformative effect of a clinical pathway on patterns of care for treatment of symptomatic bone metastases. While our single-fraction utilization rate was initially low (7.6%), and in line with national rates, the clinical pathway significantly increased the adoption rate to >15%. The use of >10 fraction regimens was also significantly decreased, and this effect was most pronounced among community practices. By 2014, >90% of courses were delivered with 1e10 fractions. This study demonstrates that clinical pathways are able to standardize practice patterns and promote change consistent with current evidence-based guidelines. Author Disclosure: B.J. Gebhardt: None. M.S. Rajagopalan: None. B.S. Gill: None. D.E. Heron: None. S.M. Rakfal: None. J.C. Flickinger: None. S. Beriwal: None.
137 Palliative Care Training in Radiation Oncology: A National Survey M. Racsa,1 J.A. Jones,2 K.V. Dharmarajan,3 A. Spektor,1 S. Noveroske,1 R.L. Wei,4 and T.A. Balboni1; 1Dana-Farber Cancer Institute, Boston,
International Journal of Radiation Oncology Biology Physics
without replacement using a propensity score algorithm for age, T stage, systemic therapy use, bra cup size, type of boost (photon vs electron), grade, lymphovascular invasion, and ER/PR status. Adverse events during RT were considered acute, while events >1.5months after RT were considered late. All side effects were graded based on CTCAE v3. Patient reported cosmesis was scored using the Harvard scale (1 Z excellent, 2 Z good, 3 Z fair, 4 Z poor). Kaplan-Meier curves and Cox proportional hazard models with robust standard errors were used to estimate local control (LC). Proportions were evaluated using Mantel-Haenszel tests to account for the effect of matching. Results: Median follow-up was 52 months (range, 3.5e130). Median age was 56 years (range, 31e88). The HRT patients included 19% Tis, 65% T1, and 16% T2 tumors; 86% were node negative. Eighty percent had negative margins, 18% had close (>0 and <2 mm) margins, and 2% had positive margins. The majority of pts received systemic therapy (45% endocrine therapy, 10% chemotherapy, and 22% both). We matched 241 of the 247 HRT pts to 482 CRT pts with no significant differences between groups except more unknown grade in CRT group. Eight-year LC was 97.5% for HRT versus 96.6% in the CRT group (P Z .78). There was no significant difference in any grade acute skin erythema in HRT versus CRT (91.3% vs 90.9%, P Z .89). Grade 2+ acute side effects were more frequent in CRT versus HRT (47.1% vs 18.7%, P < 0.01). There was no difference in any grade late side effects experienced in the CRT versus HRT group (47.7% vs 41.5%, P Z .12); 79% of late side effects in both groups were grade 1. The most common late side effects were edema, hyperpigmentation, erythema, and fibrosis. Mean pt reported cosmesis scores were similar at 3 years for HRT versus CRT (1.9 vs 1.9). Conclusion: The 4-week course of hypofractionated whole-breast radiation with incorporated boost was associated with excellent long-term LC, less acute side effects, similar cosmesis, and late side effects compared to conventional fractionation with sequential boost. Author Disclosure: L. Wang: None. C.T. Murphy: None. E. Handorf: None. G.M. Freedman: None. M.E. Johnson: None. T. Shaikh: None. S.B. Hayes: None. R.J. Bleicher: None. L. Goldstein: None. P.R. Anderson: None.
surgery (BCS) by a cooperative group of institutions. Single entry brachytherapy device results have been reported, but this is the first report with a large cohort of patients treated by MIB. Materials/Methods: Five institutions with extensive experience in treating select breast cancers with MIB contributed their experience to this retrospective clinical study. From March 1997 to August 2013, 1,372 patients with Stage Tis, T1e2, N0, and N1 (<3 positive nodes without extracapsular extension) underwent BCS with clear margins and pathologic size <3 cm, followed by APBI using interstitial multicatheter brachytherapy. All patients who had documentation of toxicity and cosmesis comprise this report, with 800 in the cosmesis evaluation alone. Mean age was 60.4 +/- 10.8 years. All patients received 32e34 Gy in 8e10 fractions over 4e5 days with high-dose-rate or 45 Gy over 3e5 days low-dose-rate Iridium-192 seeds. One hundred thirty-five patients (17.1%) received chemotherapy and 503 (68.7%) endocrine therapy. Cosmesis, toxicities, and subsequent mastectomy rates (MR) were evaluated at yearly intervals. Results: The overall median follow-up was 82 months (range, 1e245 months); however, the median follow-up for the assessment of toxicities was 48 months. For cosmesis, 612 of the 800 patients had at least 2 years of follow-up. Only 79 had follow-up of 1 year or less. Subsequent mastectomy rates were 0% (<1 year), 1% (1e2 years), 2% (2e5 years), and 2% (>6 years). Results are given in the Table below. Conclusion: This cooperative multi-institutional study is the largest published report of toxicity and cosmetic outcomes of patients treated by MIB. This radiation therapy method to complete breast conserving therapy was associated with excellent cosmetic outcomes and low-toxicity rates that change over time but remain acceptable beyond 5 years. Author Disclosure: R.R. Kuske: Consultant; Elekta. Minor Stock Option; Cianna. M. Kamrava: None. P.Y. Chen: None. J.K. Hayes: None. B.M. Anderson: None. C.A. Quiet: None. J. Wang: None. D. Veruttipong: None. M. Snyder: None. D. Demanes: None.
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Short and Long-term Toxicity and Cosmesis After Interstitial Multicatheter Brachytherapy for Accelerated Partial-Breast Irradiation: A Multi-institutional Study R.R. Kuske,1 M. Kamrava,2 P.Y. Chen,3 J.K. Hayes,4 B.M. Anderson,5 C.A. Quiet,6 J. Wang,2 D. Veruttipong,7 M. Snyder,1 and D.J. Demanes7; 1 Arizona Breast Cancer Specialists, Scottsdale, AZ, 2UCLA, Los Angeles, CA, 3Beaumont Health System, Royal Oak, MI, 4Gamma West Cancer Services, Salt Lake City, UT, 5University of Wisconsin Office of CME, Madison, WI, 6Arizona Breast Cancer Specialists, Arizona Center for Cancer Care, Phoenix, AZ, 7University of California, Los Angeles, Los Angeles, CA
Higher Mean Heart Dose With Brachytherapy Based Accelerated Partial-Breast Irradiation Compared to External Beam Whole-Breast Irradiation With Breath-Hold in Women With Left-Sided Tumors E. Holliday,1 S.M. Kirsner,2 H.D. Thames,3 B. Mason,4 C. Nelson,5 and E.S. Bloom3; 1MD Anderson Cancer Center, Houston, TX, 2The University of Texas MD Anderson Cancer Center, Houston, TX, 3MD Anderson Cancer Center, Houston, TX, 4University of Texas MD Anderson Cancer Center, Houston, TX, 5The University of Texas MD Anderson Cancer Center, San Antonio, TX
Purpose/Objective(s): To report toxicity and cosmesis outcomes after multicatheter interstitial brachytherapy (MIB) for accelerated partialbreast irradiation (APBI) for select breast cancers after breast conserving
Oral Scientific Abstracts 133; Table Toxicity Cosmesis: Fair/Poor (800) Fibrosis N (502) Grade 2/3/4 Telangiectasia N (503) Grade 1/2 Infection N (597) Grade 2/3/4 Fat Necrosis N (452) Grade 2/3
Eval at <1 yr
Eval at 1e2 yrs
Eval at 2e5 yrs
Eval at >6yrs
1%/1%
3%/0%
7%/2%
8%/1%
79 9%/0% 100 4%/0% 158 1%/0% 136 0%
67 18%/0% 39 31%/5% 18 11%/0% 28 0%/4%
238 8%/0.4% 248 15%/3% 190 14%/0% 197 2%/0%
118 12%/0% 116 7%/3% 41 18%/0% 91 1%/0%
Purpose/Objective(s): Accelerated partial-breast irradiation (APBI) is utilized as an alternative to whole-breast irradiation (WBI) for selected low-risk breast cancer (BCa) patients. During APBI treatment planning, dose is minimized to the skin and ribs; however, for left-sided tumors, dose to the heart is also a concern. We present a comparison of mean heart and coronary artery doses between patients treated with APBI and patients treated with WBI utilizing a deep inspiration breath-hold technique (DIBH-WBI). Materials/Methods: One hundred patients with left-sided, early-stage BCa were identified. Fifty underwent single-entry catheter-based APBI with a Contura (N Z 11) or SAVI (N Z 39) device, and 50 underwent DIBH-WBI. Four targets were delineated: heart, left anterior descending/ interventricular branch (LAD/IVB), left main (LM) and right coronary artery (RCA). Mean SD doses to the heart and coronary vessels were calculated from APBI treatment plans (34 Gy in 3.4 Gy twice daily fractions). The same doses were calculated for the DIBH-WBI cohort utilizing 4 plans generated from the same set up: 50 Gy in 25 fractions (50/25), 50/25 + 10/5 boost, 40.05/15, and 40.05/15 + 10/5 boost. Biologically effective doses (BED) were calculated using an assumed repair halftime of 4 h and a/b ratio of 3 Gy.
Volume 93 Number 3S Supplement 2015 Results: Mean doses to the heart were higher (P < .0001) for APBI (2.23 0.91 Gy) than for BH-WBI plans (0.67 0.14 Gy for 50/25, 0.90 0.36 Gy for 50/25 + boost, 0.53 0.11 Gy for 40/15, 0.77 0.35 Gy for 40/15 + boost). BEDs to the heart were 0.67 0.15 (50/25), 1.1 0.39 (50/25 + boost), 0.54 0.12 (40/15), and 0.96 0.37 Gy (40/15 + boost), each significantly lower than for APBI (2.50 1.13 Gy, P < .0001). Statistical comparisons of APBI with BH-WBI were similar for mean doses and BEDs: differences in mean doses and BEDs to LAD/IVB, LM, and RCA were not as large, but (with the exception of LAD/IVB for 50/25 + boost P Z .0245, and 40/15 + boost P Z .0023) still highly significant (P < .0001). Conclusion: In our cohort of women with left-sided BCa, APBI resulted in significantly higher mean dose and BED to the heart and coronary vessels when compared to WBI utilizing a breath-hold technique. Long-term assessment of late effects in these tissues will be required to determine whether these differences are clinically significant. Author Disclosure: E. Holliday: None. S.M. Kirsner: None. H.D. Thames: None. B. Mason: None. C. Nelson: None. E. Bloom: None.
135 Stereotactic Body Radiation Therapy for Early-Stage Breast Cancer Using a Robotic Linear Accelerator J.A. Haas,1 S.R. Blacksburg,1 F. Monteleone,1 D. Catell,2 A.E. Gittleman,2 O. Clancey,1 H. Staszewski,1 W. Reed,1 M. Giambona,1 A. Sanchez,1 D. Accordino,1 S. Lowery,3 and M.R. Witten1; 1Winthrop-University Hospital, Mineola, NY, 2Winthrop-University Hospital, Mineola, NY, 3 Winthrop-University Hospital, Mineola, NY Purpose/Objective(s): Standard radiation therapy for patients with breast cancer desiring breast conservation typically consists of lumpectomy followed by radiation. Radiation can either be delivered to the whole-breast or to part of the breast. Whole-breast radiation is typically given daily for 3e6 weeks depending on the dose/fractionation scheme. When partial-breast irradiation is given, often an implanted catheter is used to deliver a conformal dose of radiation to the lumpectomy cavity in an accelerated manner over one week. In properly selected patients, the results for partial-breast irradiation appear comparable to results for conventional whole-breast radiation. We examined the safety and efficacy of using an accelerated dose/fractionation schedule with a robotic linear accelerator for selected patients with early-stage breast cancer after lumpectomy. We reported on our technique and early results. Materials/Methods: Twenty-six consecutive patients with early-stage breast cancer were enrolled on an IRB approved breast protocol. Eligibility included Stage 0/I/II (<3 cm) Age >45, margins negative. One patient had fiducial markers placed by the surgeon. The other 25 patients had fiducial markers placed by the treating radiation oncologist using image guidance on a CT simulator with coordinate placement determined by the physics/dosimetry staff for optimal location. Patients were immobilized either using a thermoplastic cast with a hole removed around the areola to allow for reproducibility daily or with an alpha cradle to allow the breast to remain in its natural position. All patients received a dose of 3,000 cGy in 5 fractions of 600 cGy each given on five consecutive days. The median number of beams was 86. The median prescription isodose line was 71%. This isodose was chosen to allow for a more rapid fall of dose beyond the target volume to more accurately emulate HDR treatment. Results: With a median follow-up of 27 months, (range, 3e48 months) all 26 patients (100%) remain locally controlled with no evidence of disease following treatment. RTOG Grade 1 dry skin desquamation occurred in 1 of 26 patients. The cosmesis was good-excellent in all 26 patients using the Harvard cosmesis scale. Conclusion: Stereotactic body radiosurgery for early-stage breast cancer using a robotic linear accelerator is very well tolerated and efficacious for selected patients desiring breast conservation after lumpectomy. More
Oral Scientific Sessions
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accrual and further follow-up will be required to see if these results remain durable. Author Disclosure: J.A. Haas: Honoraria; Accuray. S.R. Blacksburg: Speaker’s Bureau; Bayer. F. Monteleone: None. D. Catell: None. A.E. Gittleman: None. O. Clancey: None. H. Staszewski: None. W. Reed: None. M. Giambona: None. A. Sanchez: None. D. Accordino: None. S. Lowery: None. M.R. Witten: None.
136 The Impact of Dynamic Changes to a Bone Metastases Pathway in a Large Integrated National Cancer Institute Designated Comprehensive Cancer Center Network B.J. Gebhardt, M.S. Rajagopalan, B.S. Gill, D.E. Heron, S.M. Rakfal, J.C. Flickinger, Sr, and S. Beriwal; University of Pittsburgh Cancer Institute, Pittsburgh, PA Purpose/Objective(s): Multiple studies suggest equivalent pain relief from bone metastases following radiation therapy with either 10 fraction regimens or shorter courses. Although ASTRO evidence-based guidelines and the Choosing WiselyÒ campaign recommend single-fraction treatments and caution against routinely using extended (>10 fraction) courses, recent publications report single-fraction utilization rates below 5%. We evaluated the impact of our bone metastasis clinical pathway on the adoption of short-course palliative radiation therapy in a large, integrated radiation oncology network. Materials/Methods: In 2003, we implemented a clinical pathway for the management of bone metastases with palliative radiation therapy. In 2009, we required the entry of management decisions into an online tool that records pathway choices and subjects off-pathway choices to peer-review. The pathway specified 1 or 5 fractions for symptomatic bone metastases with the option of 10e14 fractions for certain clinical situations. In 2014, the pathway was modified to encourage single-fraction treatment, and the use of >10 fractions was considered off-pathway. Data were obtained from 16 integrated sites (4 central academic, 12 community locations) from 2003 through 2014. Multivariate logistic regression was conducted to establish factors associated with treatment with a single fraction and with >10 fractions. Results: In this study, 12,678 unique courses were delivered with 61% delivered in the community and 39% in academic locations. From 2003e2008, the single-fraction utilization rate was 7.6%. This increased to 10.9% from 2009e2013 and to 15.8% in 2014. Compared to 2003e2008, the odds-ratios for single-fraction utilization were 1.59 (95% CI: 1.39e1.81) and 2.58 (95% CI: 2.11e3.15), for 2009e2013 and 2014, respectively. Academic physicians were significantly more likely to treat with a single-fraction (OR: 5.00, 95% CI: 4.38e5.71). Utilization of >10 fraction regimens decreased from 18.6% from 2003e2008 to 15.2% from 2009e2013 and to 9.7% in 2014, predominantly from rates in the community physician subset changing from 24.3% to 21.2% to 12.7%, respectively (P < .0001). Conclusion: This study demonstrates the transformative effect of a clinical pathway on patterns of care for treatment of symptomatic bone metastases. While our single-fraction utilization rate was initially low (7.6%), and in line with national rates, the clinical pathway significantly increased the adoption rate to >15%. The use of >10 fraction regimens was also significantly decreased, and this effect was most pronounced among community practices. By 2014, >90% of courses were delivered with 1e10 fractions. This study demonstrates that clinical pathways are able to standardize practice patterns and promote change consistent with current evidence-based guidelines. Author Disclosure: B.J. Gebhardt: None. M.S. Rajagopalan: None. B.S. Gill: None. D.E. Heron: None. S.M. Rakfal: None. J.C. Flickinger: None. S. Beriwal: None.
137 Palliative Care Training in Radiation Oncology: A National Survey M. Racsa,1 J.A. Jones,2 K.V. Dharmarajan,3 A. Spektor,1 S. Noveroske,1 R.L. Wei,4 and T.A. Balboni1; 1Dana-Farber Cancer Institute, Boston,