Author of

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  P2.01 - Advanced NSCLC (Not CME Accredited Session) (ID 950)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall

  • 26809

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    P2.01-15 - A Radiologist-Led Training Workshop for MR Based Normal Tissue and Tumour Delineation for Lung Cancer Radiotherapy. (ID 13857)

    16:45 - 18:00  |  Author(s): Hamid Sheikh
    • Abstract
    • Slides

    Background
    

    A potential benefit of MR-image guided radiotherapy (MRIgRT) in lung cancer is the reduction of treatment related uncertainties through improved soft tissue contrast. However, this benefit may be obscured by inter-observer variation in gross tumour volume (GTV) and organ at risk (OAR) contouring. A radiologist led workshop was organised to provide training in such contouring on MR.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    Planning CT, PET-CT and MRI were acquired in four lung cancer patients. MR sequences included 3D radial gradient echo, T2 DIXON Turbo Spin Echo (TSE), and T2 TSE with and without fat-sat. Data sets were local rigidly registered and imported into the so-called “Big Brother” contouring software.

    The radiologist led teaching on OAR and GTV contouring used an MR lung atlas (produced by this group). Seven radiation oncologists contoured the brachial plexus (BP), heart, proximal bronchial tree, oesophagus and GTV. This was followed by a multi-disciplinary group discussion (oncologists, radiologists and physicists) on the contouring challenges and subsequently contours were reviewed and the atlas adjusted.

    4c3880bb027f159e801041b1021e88e8 Result
    

    The BP and heart were the most difficult OARs to contour and showed the largest inter-observer variation. Following contour review and discussion between radiologist and oncologists updates to atlas and protocols were made. The GTV was found to be most challenging at the soft tissue interfaces and requires further work (Figure 1).

    

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    This early work demonstrates the need for radiologist-led training in OAR and GTV contouring in lung cancer patients using MR images. This will be especially important for the integration of MR into treatment planning and an MRIgRT adaptive workflow. We have arranged future workshops in order to provide further training and to assess inter-observer variation in OAR and GTV contouring using MR on more cases.

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