ASTRO Annual Meeting
McCormick Place, Chicago
October 24 - 27, 2021

ASTRO will be accepting abstract submissions Wednesday, December 16, 2020, through Monday, March 1, 2021.

Deadline to Submit: Monday, March 1, 2021, at 11:59 p.m. Pacific time
Notifications of acceptance or decline: Wednesday, May 12, 2021

Late-breaking Abstract Submission Dates: Monday, July 26, 2021, to Monday, August 9, 2021
Late-breaking Abstract Notification: Tuesday, August 31, 2021


  1. Sponsorship or ASTRO membership is not required to submit an abstract.
  2. Abstracts must be received by 11:59 p.m. Pacific time, Monday, March 1, 2021. 
  3. All studies in oncology, radiation oncology and radiation-therapy for non-oncologic conditions is eligible for submission. This includes basic and translational science, technology-related, health services research, epidemiologic, patient-focused clinical studies and all phases of trials.
  4. An abstract may only be submitted once. Abstracts of clinically-related subjects should be combined into a single abstract. Submission of multiple abstracts on a single study may result in the rejection of one or more abstracts.
  5. Submit new research. Data from the long-term follow-up of previously presented clinical trials may be submitted only if significant new information can be shown. 
  6. Obligation to Register: Acceptance of the abstract by the committee obligates the author to present the paper and pay the meeting registration fee. If circumstances prevent attendance, you must notify ASTRO and arrange for an alternate presenter, preferably a co-author in the Speaker Center. If you do not register and attend the meeting, your abstract will be removed from the program.
  7. Disclosures: The submitter must complete the disclosures for the presenter and all co-authors. Use this form to gather all co-author information and use it when entering the co-authors into the abstract submission site.
Important Deadlines
  1. Abstracts must be received by 11:59 p.m. Pacific Time, Monday, March 1, 2021. Abstracts may be edited up until the deadline. Abstracts will be considered ineligible for review if they are incomplete. Abstracts that are unpaid or have payment issues will not be considered. If you do not receive a confirmation receipt, follow up with ASTRO to confirm your “complete” status.
  2. Revisions: Please proof your abstract carefully for formatting, spelling and data errors. Pay special attention to the author order and presenting author designation. Review your confirmation email, as this is how the abstract will be published. Errors can be corrected if sent to ASTRO by July 1, 2021. After this date, we cannot make any corrections. This rule is strictly enforced.
  3. Notifications: You will be notified via email of the disposition of your abstract by May 12, 2021. Notifications are sent to the person listed as the “presenting” author.
  4. Withdrawals: If you choose to withdraw your abstract, please change your decision to “withdraw” in the Speaker Center by July 1, 2021, and notify ASTRO staff via email. After this date, your abstract will be published exactly as it was submitted in the International Journal of Radiation Oncology • Biology • Physics (Red Journal).
  5. Submission of an abstract conveys permission to be posted online and printed in the International Journal of Radiation Oncology • Biology • Physics (Red Journal) (www.redjournal.org).
Late-breaking Abstracts

Submission Site Opens: Monday, July 26, 2021
Submission Site Closes: Monday, August 9, 2021, at 11:59 p.m. Pacific time
Notifications: Tuesday, August 31, 2021

Original research abstracts will be selected for late-breaking presentations based on scientific merit, timeliness and interest to ASTRO’s membership and attendees. A special panel of peer reviewers will review the late-breaking abstracts using the highest standards. Abstracts should only be submitted as late-breaking abstracts if they meet the Following Criteria:

  • The research is limited to highly significant and timely findings in clinical oncology, radiobiology or medical physics that were not available during the March 1, 2021 submission process.
  • Only abstracts that are deemed to be of high scientific priority and that merit presentation in the Plenary, Clinical Trials, or the special Late-breaking Abstract session will be accepted.
  • Late-breaking abstracts cannot be a revision of an abstract submitted during the March 1, 2021, submission process.
  • Late-breaking abstracts must not have been submitted, presented, accepted for presentation or published in any other scientific venue.
  • Standards for accepting late-breaking abstracts for presentation are much higher than those required for abstracts accepted for the general scientific sessions.

Questions? Email us.

Presenting Author Responsibility
  1. An individual may submit more than one abstract in which he or she is indicated as the first author, but he or she may only present one oral presentation. If more than one abstract is selected for oral presentation, an alternate presenter must be assigned, preferably a co-author (this does not apply to poster presentations).
  2. It is the submitter’s responsibility to ensure up-to-date and accurate disclosures are submitted for each co-author on the abstract. ASTRO manages and reports all disclosures as submitted. Potential conflicts with commercial interest for the presenting author and all co-authors must be disclosed at the time of submission.
  3. The presenting author will receive all notifications and email communications related to the accepted abstract(s), and is responsible for informing all co-authors of acceptance to ASTRO’s Annual Meeting.
  4. ASTRO has developed a policy to handle any violations to the ASTRO Disclosure policy. Any reported violations will be researched and handled according to policy, which can include removal from presenting at future conferences.
  5. Obligation to Register: Acceptance of the abstract by the committee obligates the author to present the paper and pay the meeting registration fee. If circumstances prevent attendance, you must notify ASTRO and arrange for an alternate presenter, preferably a co-author. If the presenting author does not register and attend the meeting, your abstract will be removed from the program.

Presentation at Other Meetings

  1. Abstracts should contain new material that has not been presented or published prior to the ASTRO Annual Meeting, October 24 - 27, 2021. Previously presented abstracts will not be eligible for ASTRO’s official Press Program or Plenary Session.
  2. Abstract presenters with the same abstract accepted for presentation at another major medical meeting* or accepted for publication after March 1, 2021, are required to notify ASTRO's Education Team. The Scientific Committee will review and decide on a case-by-case basis if it will remain in the program.
Properly Formatted Abstract
  1. Abstracts must be properly formatted and organized into four sections identified by the following bolded headers: Purpose/Objectives, Materials/Methods, Results and Conclusions.
  2. Abstracts should include a scientific hypothesis in the Purpose/Objectives section, and implications for research, policy or practice in the Conclusions section, when applicable.
  3. Presentations must give a balanced view of therapeutic options. Brand names of pharmaceuticals and trade names of medical devices cannot be used in the title or body of the abstract. ASTRO reserves the right to replace proprietary names with generic names.
  4. Institution names should not be included in the title or body of the abstract. Alternative language is “at one institution” or “a multi-institution” study, etc. This does not apply to cooperative research group names. 
  5. The title should not include results. 
  6. The abstract cannot contain illustrations, images or graphs. If the abstract is accepted, presenters may include these items in their on-site presentations.
  7. An abstract may contain one small table. The maximum character limit, including the title and body of the abstract, is 2,600 characters. Spaces are not counted.
  8. A maximum of 20 authors’ names may be listed on each abstract. There are no exceptions. Authorship credit should only be given if all three of the following criteria are met. There is not mechanism for listing co-lead authors, or co-PI’s. Each author must have made substantial contributions to:
    • conception and design, or analysis and interpretation of data, and
    • drafting the abstract or revising it critically for important intellectual content, and
    • final approval of the version to be submitted/published.

Special Physics Session

There will be a special Physics subcategory which will solicit cutting edge research that will exemplify this theme: “Advances in Stereotactic and Hypofractionated Response Modeling and Treatments.” Abstracts for this subcategory will be reviewed and selected by an independent panel of experts and presented in an oral session.

Special Biology Session

There will be a special Biology subcategory which will solicit cutting edge research that will exemplify this theme: “Innovative Biologic Approaches to Personalize Radiotherapy.” Abstracts for this subcategory will be reviewed and selected by an independent panel of experts and presented in an oral session.

Interim Analysis

  1. In general, ASTRO does not accept abstracts reporting an interim analysis that is intended to evaluate experimental treatment regimen(s) with respect to efficacy or safety at any time prior to formal completion of a trial.
  2. Abstracts reporting trial process updates, such as accrual, baseline characteristics, and non-protocol specific safety information, will be considered for posters only for promotional purposes.

Database Studies

  1. Retrospective registry databases, such as National Cancer Database (NCDB), Surveillance, Epidemiology and End Results (SEER), etc., are valuable resources for patterns of care assessment, and may generate important evidence for comparative effectiveness research.
  2. For comparative effectiveness reports, prioritization will be given to those when the level 1 evidence from randomized trials is obsolete or difficult to obtain. Abstracts should include brief descriptions on statistical methods and justifications, such as the choice of statistical significance level, effect size, methods for confounding adjustment, etc., to facilitate proper interpretations.
Abstract Scoring Criteria

Abstracts will be scored by blind peer review based on the following criteria:

  • Does the abstract address an important and novel question?
  • Does the study design permit the question to be answered?
  • Are the endpoints of the study clearly defined?
  • Is there an appropriate use of statistics?
  • Are the methods described in sufficient detail?
  • Are the conclusions supported by the data?

Specific questions for prospective clinical trials:

  • What were the scientific hypothesis and primary endpoint?
  • What were the eligibility criteria and study patient characteristics?
  • What statistical model and assumptions were used?
  • What was the toxicity assessment?
  • What were the limitations?
  • Was there a rationale, either clinical or laboratory, underlying the study design?
  • Is it either promising enough to pursue or negative enough that presentation would prevent other investigators from wasting efforts?

Specific questions for retrospective observational studies:

  • What are the scientific hypothesis and outcomes reported?
  • What is the data source and how was follow-up attained?
  • Is the cohort well described and reasonably homogeneous?
  • Have attempts been made to account for biases inherent in retrospective reviews?
  • What statistical methods were used?
  • Are the conclusions appropriate to the study design?
Abstract Policies

Policy on Studies Sponsored by Commercial Interests

  1. Abstracts may be submitted from commercial entities (those producing, marketing, reselling or distributing health care goods or services consumed by, or used on, patients reporting on the discovery of their scientific research). Such presentations will be subject to a rigorous peer review to ensure the validity of the research results and conclusions. In addition, abstract content is subject to change after review so that it is not biased toward any proprietary interests.
  2. A commercial interest is defined as any entity developing, producing, marketing, reselling or distributing health care goods or services consumed by or used on patients. Any potential conflict will be identified and managed according to ACCME guidelines, and ASTRO’s COI management policies.
  3. The presenting author of an abstract must NOT have a relevant/ specific ownership interest, i.e., owner, founder, partner, etc., in the scientific content in the abstract. If a conflict of interest exists, the abstract must be presented by a co-author with no relevant ownership interests.
  4. If the presenting author is employed by a commercial interest, as defined above, an alternate presenter must be named. This applies only to abstracts presented in sessions selected to receive CME, such as oral scientific and Quick Pitch scientific sessions.
  5. ASTRO will exercise all rights in ensuring that abstracts reporting the discovery of scientific research remain in compliance with ACCME standards for offering CME.

Disclosure Policy

ASTRO is an accredited provider of continuing medical education and adheres to the policies and standards set forth by the Accreditation Council for Continuing Medical Education (ACCME). As such, abstract authors are required to disclose relationships with commercial interests. A commercial interest is defined as “any entity developing, producing, marketing, re-selling or distributing health care goods or services consumed by or used on patients.”

To ensure its compliance, ASTRO expects that the content and related materials will promote improvements or quality in health care and not a specific proprietary business interest or commercial bias.

We employ several strategies to ensure absence of bias:

  • Presenters are required to provide disclosure of relationships with commercial interests.
  • Presenters are required to provide a balanced view of therapeutic options.
  • All abstracts undergo a rigorous peer review process.
  • Potential conflicts are managed by additional committee review, advance slide review and session audits.

Embargo Policy and ASTRO Press Policy

All abstracts to be presented at ASTRO’s Annual Meeting are embargoed until the date and time of scientific presentation or presentation at an ASTRO news briefing, whichever occurs first. The embargo policy applies to all abstracts regardless of whether information is obtained from another source.

Embargo violations by media professionals may result in suspension of credentials at the ASTRO Annual Meeting as well as future meetings and may also impact the ability to receive advance media materials for future meetings. Embargo violations by abstract authors and/or sponsors may result in removal of the abstract from the scientific program. Abstract authors are responsible for notifying financial and other sponsors about this embargo policy.

Questions about the embargo policy may be directed to ASTRO’s media relations team.

The full text of the abstracts selected for oral and poster presentation will be available online at the start of ASTRO’s Annual Meeting. Abstracts also will be published in a supplement of the International Journal of Radiation Oncology • Biology • Physics (www.redjournal.org).

American Society for Radiation Oncology
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Arlington, VA 22202
Telephone: 703-502-1550


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