Terms of Reference


The RECIST Working Group (RWG) was established in 1995 to review the objective response criteria in use at the time and to explore the utility of the use of unidimensional measurements in response assessment, as proposed by NCIC CTG (now CCTG). The initial working group was led by academic members of the EORTC, CCTG and NCI (USA), with a database being created and maintained under the governance of the EORTC. Over the years, the membership of the Working Group was expanded to include other interested or expert members, including some representation from the pharmaceutical industry, as original members joined pharma, or expertise was identified.

RECIST V1 was successfully implemented in 2000, and an update (RECIST 1.1) was released in 2009 and iRECIST in 2017.  Efforts are underway to validate the proposed iRECIST criteria with clinical trial data.  Further updates to RECIST are being explored, including the use of functional imaging or radiomics and the addition of ctDNA to response assessment.   Increasingly, liaisons with other groups or organisations involved in related initiatives such as imaging technology and database creation will be required. Formal terms of reference have therefore been developed to address structure, membership and governance.

Funding and Support

Administrative support is provided by the EORTC as well as modest funding for the activities of the RWG.

The EORTC is responsible for the maintenance of the database.

Review and Approval

These Terms of Reference will be approved by committee members, undergo review one year after initial approval, and thereafter every 3 years thereafter to ensure relevance and applicability.

Structure and Governance

Steering Committee

  1. The steering committee (SC) is comprised of
    1. the Chair and Co-Chair
    2. Plus 2-3 additional members.
      The steering committee will therefore consist of a total of four-five members, with a minimum of one core SC member representing each of the founder groups (the EORTC, the CCTG and the NCI (USA)). Up to two additional SC members will be selected from the RWG by the Chair and Co-Chair.

      Ex officio an EORTC staff member will support the steering committee.

  2. The responsibilities of the steering committee include
    1. Oversight of the RWG activities, including financial and administrative aspects
    2. Approval of the terms of reference and any amendments thereof
    3. Annual review of the activities and progress of the RWG
    4. Setting the agenda for the ongoing activities of the RWG

The Chair and Co-Chair

  1. Will be selected by the Steering Committee from the full members of the RWG.
    1. Ideally, the Chair and Co-Chair will have different expertise (i.e., clinician, imaging specialist, statistician).
    2. Terms of appointment are 3 years, renewable no more than twice.
  2. The responsibilities of the Chair and Co-Chair include
    1. Organising bi-annual meetings or conference calls of the RWG, ensuring appropriate agendas and minutes are kept.
    2. Setting objectives and plans for the RWG.
    3. Ensuring the objectives of the RWG are met.
    4. Ensuring the membership is appropriate, and appointing new members as needed
    5. Inviting prior members of the SC to join the Advisory Expert Panel (AEP), and holding twice-yearly meetings with the AEP to update those members on the progress of the RWG.


Although the RWG was originally composed of members from academia, RWG recognises that non-academic contributions have been very helpful.  Further, pharma are an important source of databases to validate or test hypotheses. In addition, input from observers such as from Health Authorities has been valuable. Thus, two categories of membership are proposed: core members and observers. The number of observers is limited to 10. Observers are non-voting and are in addition to the core committee.

Recognising that large committees are often less efficient than smaller ones, membership to the RWG will be limited to no more than 20 members, including the chair and co-chair.  A quorum is designated as a ≥50%. In the case of a split vote, the RWG Chair will cast the deciding vote. Minority opinions will be provided in any minutes as appropriate.

Taskforces will be created as needed, and will include RWG members, associate members and volunteers (i.e., non RWG members if required) for specific issues or tasks, and will be dissolved when the task has been completed. Each Taskforce will be led by a Taskforce Chair, appointed by the RWG Chair/Co-Chair.

Responsibilities of RWG Members and Observers

Core Members

  1. Participate in RWG Steering Committee & Members meetings as convened, in addition to those meetings of any Taskforce to which they have been appointed
  2. Attend meetings and conference calls. Inability to attend ≥ 2 meetings sequentially should lead to the members review of membership.
  3. Review documents sent prior to or in between meetings and provide advice or comments as requested.
  4. Identify areas where further analysis and investigation are needed to improve RECIST or Taskforce investigation, as applicable.
  5. Take the lead in development of the new RECIST version.
  6. Develop and implement a plan to disseminate and publish the recommendations and guidance formulated by the RWG.
  7. Review proposals for new members.


  1. Attend meetings and conference calls.
  2. Review documents sent prior to or in between meetings and provide advice or comments as requested.
  3. Identify areas where further analysis and investigation are needed to improve the new RECIST version.

Membership & Terms

  1. Membership to the RWG will be limited to 20 members, selected by the Chair/Co-Chair.
  2. Potential members may be nominated by RWG members, be self-nominated, or approached based on their expertise.
  3. The term of membership is 3 years, renewable twice.
  4. The Chair/Co-Chair and the Steering Committee will review membership every 2 years.
  5. Membership should be balanced between Europe and North America, and between disciplines (clinical, imaging, translational, statistical, regulatory).
  6. Non-academic members are invited based on their personal expertise, rather than as representatives of a specific commercial organisation.
  7. Observers will either be invited or, in certain circumstances, be proposed by other interested groups.
  8. All members will report their conflicts of interest upon appointment to the RWG, and at least annually, or if a new situation develops that might pose a conflict of interest with their RWG activities.