Accelerated Partial Breast Irradiation

Publication Date: April 1, 2017
Last Updated: March 14, 2022

Which patients may be considered for APBI outside of a clinical trial?

Age

Include age greater than or equal to 50 years in the “suitable” group. (WR, M)
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Patients who are aged 40 to 49 years and who meet all other elements of suitability are considered “cautionary.” (WR, L)
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Retain patients with age younger than 40 years or those who are 40 to 49 years without meeting other elements of suitable in the “unsuitable” group. (WR)
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Margins

Maintain the current selection criteria for “suitable,” “cautionary,” and “unsuitable” patients based on margin status. ( WR , )
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Pure DCIS

Include patients with low-risk DCIS as per RTOG 9804 criteria (ie, screen-detected, low to intermediate nuclear grade, less than or equal to 2.5 cm size, resected with margins negative at ≥3 mm), in the “suitable” group. ( WR , M )
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Which patients may be considered for intraoperative PBI?

Patients interested in cancer control equivalent to that achieved with WBI postlumpectomy for breast conservation should be counseled that in 2 clinical trials the risk of IBTR was higher with IORT. (SR, H)
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Electron beam IORT should be restricted to women with invasive cancer considered “suitable” for PBI based on the results of a multivariate analysis with median follow-up of 5.8 years. (SR, M)
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Low-energy x-ray IORT for PBI should be used within the context of a prospective registry or clinical trial, per ASTRO Coverage with Evidence Development (CED) statement. When used, it should be restricted to women with invasive cancer considered “suitable” for partial breast irradiation based on the data at the time of this review. (WR, M)
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Recommendation Grading

Overview

Title

Accelerated Partial Breast Irradiation

Authoring Organization

Publication Month/Year

April 1, 2017

Last Updated Month/Year

April 13, 2023

Supplemental Implementation Tools

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Document Objectives

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.

Target Patient Population

Patients with early breast cancer

Inclusion Criteria

Female, Male, Adolescent, Adult, Older adult

Health Care Settings

Ambulatory, Hospital, Operating and recovery room, Outpatient, Radiology services

Intended Users

Nurse, nurse practitioner, physician, physician assistant

Scope

Assessment and screening, Management, Treatment

Diseases/Conditions (MeSH)

D007430 - Intraoperative Care

Keywords

breast cancer, radiation therapy, Adjuvant Radiation Therapy, oncology, Breast Cancer

Methodology

Number of Source Documents
44
Literature Search Start Date
March 1, 2008
Literature Search End Date
March 31, 2014
Description of External Review Process
The initial draft was reviewed by four expert reviewers (see acknowledgements) and ASTRO legal counsel.
Description of Public Comment Process
A revised draft was placed on the ASTRO Web site in June 2016 for public comment.
Specialties Involved
Obstetrics And Gynecology, Oncology, Radiation Oncology, Interventional Radiology, Oncology, Radiology
Description of Systematic Review
The literature search results go through a series of reviews to synthesize the evidence based on the pre-defined inclusion and exclusion criteria to determine their relevance to the identified KQs and scope of the guideline. An independent literature review team dual-screens first the titles and then the abstracts of the articles included from title screening. The studies included after the second round are reviewed and further refined by the task force. Study characteristics from the final group of selected articles is abstracted into detailed evidence tables, which summarize the primary evidence base for the guideline and are used to inform the recommendations. The evidence tables are published as a supplement to the document.
List of Questions
This update addresses key question (KQ) 1 from the original guideline: Which patients may be considered for APBI outside of a clinical trial? It also considers a new KQ: Which patients may be considered for intraoperative partial breast irradiation (PBI)?
Description of Study Criteria
A systematic literature review in PubMed formed the basis of the guideline using the same terms as the original Consensus Statement. The searches identified English-language studies between May 2008 and March 2014 that evaluated patients 18 and older with stage I/II breast cancer who received accelerated radiotherapy following breast conserving surgery. Due to the complexity of the topic and the length of time to the completion of the paper, the literature search was extended to March 2016.
Description of Search Strategy
A total of 419 articles that included the following key words were identified: Breast neoplasms/radiotherapy, accelerated, balloon, brachytherapy, catheter, implant, implantation, interstitial, intraoperative, limited, partial, Savi, Contura, TARGIT, Intrabeam, Xoft, Clearbeam, IOERT, IORT, and Mobitron. The electronic searches were supplemented by hand searches and articles suggested by the chair.
Description of Study Selection
The literature search results go through a series of reviews to synthesize the evidence based on the pre-defined inclusion and exclusion criteria to determine their relevance to the identified KQs and scope of the guideline. An independent literature review team dual-screens first the titles and then the abstracts of the articles included from title screening. The studies included after the second round are reviewed and further refined by the task force. Study characteristics from the final group of selected articles is abstracted into detailed evidence tables, which summarize the primary evidence base for the guideline and are used to inform the recommendations. The evidence tables are published as a supplement to the document.
Description of Evidence Analysis Methods
To ensure high standards in developing ASTRO’s guidelines, a rigorous, transparent, reproducible, and unbiased review of the evidence is paramount. Through a series of conference calls, small work groups synthesize and summarize the evidence for each KQ to determine the quality of the evidence. These discussions inform the development of draft recommendations, which include assigning the recommendation strength and overall quality of evidence ratings, as defined in Table 1 of Clinical Guideline Manual. It is important that guideline recommendations be clear and actionable statements that align with the PICOTS framework, denoting in most instances the patient group, intervention, comparator, and outcome. Implementation remarks are included sparingly to enhance the reader’s interpretation and understanding of a recommendation or to append information like timing, setting, or dosing details to the recommendation.
Description of Evidence Grading
For each statement, the strength of the recommendation and supporting evidence were rated using the American College of Physicians (ACP) process (see Appendix).3 In determining recommendation strength, balance of risks and benefits was assessed. The chair initially assigned the ratings, which the task force later approved. A strong recommendation was defined as the benefit of the intervention outweighs the risk, or vice versa, with uniform consensus. A weak recommendation was defined as the benefit of the intervention equals the risk, or vice versa, with uniform or non-uniform consensus.
Description of Recommendation Grading
The task force consensus on the statements was evaluated through a modified Delphi approach. The task force members independently rated their agreement with each recommendation on a five-point Likert scale, from strongly disagree to strongly agree using an electronic survey. A pre-specified threshold of greater than or equal to 75% “agree” or “strongly agree” responses indicated consensus was achieved.2 A total of four survey rounds, with revision as needed after each survey, were conducted to ascertain consensus on all the recommendation statements.
Company/Author Disclosures
Before initiation of this update, all members of the Update Task Force were required to complete disclosure statements. These statements are maintained at the American Society for Radiation Oncology (ASTRO) Headquarters in Arlington, VA, and pertinent disclosures are published with this report. The ASTRO Conflict of Interest Disclosure Statement seeks to provide a broad disclosure of outside interests. Where a potential conflict is detected, the disclosure and any remedial measures to address potential conflicts are taken and noted in the consensus statement.
Percentage of Authors Reporting COI
75