Abstract ES1-1: Accelerated partial breast irradiation: Update of an ASTRO consensus guideline
Authors: Correa CR 
Published: February 2018

Abstract
Authors
Correa CRa, Harris EEb, Leonardi MCc, Smith BDd, Taghian AGe, Thompson AMf, White Jg, Harris JRh; aDept. of Radiation Oncology, Faxton St. Luke's Healthcare, Utica, NY, bDept. of Radiation Oncology, E. Carolina Univ., Greenville, NC, cDept. of Radiation Oncology, European Inst. of Oncology, Milan, Italy, dDept. of Radiation Oncology and fDept. of Breast Surgical Oncology, The Univ. of Texas MD Anderson Cancer Center, Houston, TX, eDept. of Radiation Oncology, Massachusetts General Hosp., Boston, MA, gDept. of Radiation Oncology, Ohio State Univ. Cancer Center, Columbus, OH, hDept. of Radiation Oncology, Brigham and Women's Hosp. and Dana-Farber Cancer Inst., Boston, MA
Purpose
To update the accelerated partial breast irradiation Consensus Statement published in 2009 and provide guidance on use of intraoperative radiation therapy (IORT) for partial breast irradiation in early-stage breast cancer, based on published evidence complemented by expert opinion.
Methods
A systematic PubMed search using the same terms as the original Consensus Statement yielded 419 articles; 44 articles were selected. The authors synthesized the published evidence and, through a series of conference calls and e-mails, reached consensus regarding the recommendations.
Results
The new recommendations include lowering the age in the “suitability group” from 60 to 50 years and in the “cautionary group” to 40 years for patients who meet all other elements of suitability (Table 1). Patients with low-risk ductal carcinoma in situ, as per RTOG 9804 criteria, were categorized in the “suitable” group. The task force agreed to maintain the current criteria based on margin status. Recommendations for the use of IORT for breast cancer patients include: counseling patients regarding the higher risk of ipsilateral breast tumor recurrence with IORT compared with whole breast irradiation; the need for prospective monitoring of long-term local control and toxicity with low-energy radiograph IORT given limited follow-up; and restriction of IORT to women with invasive cancer considered “suitable.”
Conclusion
These recommendations will provide updated clinical guidance regarding use of accelerated partial breast irradiation for radiation oncologists and other specialists participating in the care of breast cancer patients.
Table 1 Comparison of patient groups in original and updated consensus statementsPatient groupRisk factorOriginalUpdateSUITABLEAge≥60 y≥50 y MarginsNegative by at least 2 mmNo change T stageT1Tis or T1 DCISNot allowedIf all: screen detected, low to intermediate nuclear grade, size ≤2.5 cm, and resected with margins negative at ≥3 mmCAUTIONARYAge50-59 y40-49 y if all other criteria for "suitable" are met; ≥50 y if patient has at least 1 of the pathologic factors[lowast] and no "unsuitable" factors MarginsClose (&lt;2 mm)No change DCIS≤3 cm≤3 cm and does not meet "suitable" criteriaUNSUITABLEAge&lt;50 y&lt;40 y; 40-49 y and does not meet "cautionary" criteria MarginsPositiveNo change DCIS&gt;3 cmNo change[lowast]Pathologic factors: size 2.1-3 cm, T2, close margins (&lt;2 mm), limited/focal lymphovascular space invasion, ER(-), clinically unifocal with total size 2.1-3 cm, invasive lobular histology, pure DCIS ≤3 cm if "suitable" criteria not fully met, extensive intraductal component ≤3 cm
Citation Format: Correa CR. Accelerated partial breast irradiation: Update of an ASTRO consensus guideline [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr ES1-1.