IHERO UseCase Structure template

1. Proposed Workitem: Clinical trials submission I-Structure Template Creation, Import, and Export

• Proposal Editor: Charles Able, MS
• Editor: C. Field
• Editor: M. Wahab
• Date: N/A (Wiki keeps history)
• Version: N/A (Wiki keeps history)
• Domain: Radiation Oncology

Summary

The use of anatomical structures and structure sets is fundamental to image based treatment planning and delivery but the portability and customization of structure templates does not exist. DICOM handling of a single structure set associated with an image data set is established. Development of the structure template profile will allow the use of defined templates in building a structure set with established naming conventions. The Image Guided Therapy QA Center (ITC) and CABig have promoted and developed uniform tissue names for use in radiation oncology clinical trials. The expanded use of structure templates will increase productivity across the field of radiation oncology (virtual simulation, treatment planning and IGRT, and image review). The expanded use of structure sets and templates requires the development of well defined handling processes across platforms and systems. This makes it an ideal integration profile for the IHE-RO.

2. The Problem

1. Specific structure templates may be developed by cooperative oncology groups for certain protocols. Treatment planning systems need to be able to import the structure templates to allow for consistent identification and evaluation of clinical data for national clinical trials.

2. The use of standard naming conventions (i.e. ATC's Uniform Tissue Names for use in RTOG Advanced Technology Clinical Trials, caBIG naming convention, etc.) has not been adopted to date by the radiation oncology community. Structure Template Import/Export capability will accelerate the standardization of tissue naming.

3. Different structure templates are needed at various stages of the radiotherapy process (i.e. virtual simulation, treatment planning, image guided therapy). The ability to build, activate, and/or disable structure templates or a subset of structures (sub-template) for use at each stage of the radiotherapy process is needed.

4. The need to import and export structure templates for patients being treated at multiple institutions using different platforms exists. Patients being transferred or receiving re-treatment could benefit from the ability to import and export the structure template.

Lost productivity is at the heart of this problem. The Advanced Technology QA Consortium's Image Guided Therapy QA Center (ITC) has developed software tools to assist in reconciling discrepancies between submitted and protocol-specified structure names. Some cases still require visual inspection of images, contours to identify structures. The ITC states "the effort required to correctly identify all structures can be substantial."

The time required to re-create structures used repeatedly for specific body sites can be substantial for therapist and dosimetrist when performing virtual simulation and treatment planning. Additional time is lost during IGRT implementation by the therapist and radiation oncologist eliminating unwanted structures when reconciling the patient position. Further lost productivity results when the radiation oncologist reviews images off line when structures viewed must be customized each time an image is taken during the course of treatment.

Development of this use case can increase productivity across the field of radiation oncology.

3. Key Use Case

Patient X enters on a National Cooperative Group Trial. A treatment plan is prepared for the patient. The plan needs to be transferred to the Cooperative group. The list of contoured clinical structures can be uploaded into a structure template containing the nomenclature and format identified by the cooperative group. This information can then be exported to the cooperative group and/or other participating institutions.

a. A DICOM file containing a list of clinical structure names can be created in the treatment planning contouring workspace. Clinical structures can be contoured under each identifying structure name.

b. A DICOM file containing a list of clinical structure names can be imported into the treatment planning contouring workspace. Clinical structures can be contoured under each identifying structure name.

c. Using an existing treatment plan a structure template can be created from the structures defined in the treatment plan. The newly created structure template can be exported as a DICOM file.

4. Standards & Systems

Treatment planning system, record and verify system, virtual simulation system.

5. Discussion

This an ideal interoperability case for IHE-RO. It also promotes collaboration with clinical trials groups