DICOM-RT: Radiotherapy process and participatory roles

Background:

Radiotherapy is a complex process that requires multiple roles involving oncologists, analog location technicians, dosimetry, physiotherapists, therapists, nurses, and more. The whole process involves the imaging system, positioning System, planning system, treatment system, quality control QA system, information management system and other independent subsystems , compared to the conventional medical information system (such as his, RIS, LIS, PACS, etc.) there is a " low degree of integration of the subsystems, Such issues as large transmission data, poor real-time operation, and high learning costs .
In the first article of the column Dicom-rt series, the basic knowledge point of radiotherapy in the dicom-rt:dicom3.0 standard briefly introduces the overall flow of radiotherapy, this paper analyzes the DICOM standard and radiotherapy in IHE Oncology framework to detail the overall process of radiotherapy and the role of the people involved in each process.

Radiotherapy process: 1. Approximate radiotherapy process:

The approximate radiotherapy process is as follows:

The first step , theCT simulation machine . Collect and diagnose three-dimensional data of CT, position calibration, and archive data to storage server (PACs can be easily understood);
The second step , the geometry plan is developed (in the virtual SIM workstation to complete). By extracting three-dimensional CT data, the target area is sketched (i.e. drawing contour), and the Dicom-rt object of structure set is generated.
In the third step , the dosage plan is developed (known as the Tps,treatment planning System). By extracting three-dimensional CT data (single or multiple sets) and Structure set geometric plan data, the dose calculation is made, and the Dicom-rt object of RT Image and RT dose is generated.
Fourth Step , plan confirmation . Import the relevant data prior to validation and transfer data (this step may require tds,treatment Delivery system assistance);
The fifth step , the treatment process . During the latest IGRT radiotherapy treatment, this step will capture EPID, KV-CBCT, KV-CBCT or MV CT volumetric images , monitor the patient's treatment posture and dosage in real time/online/offline, and intervene at all times to re-establish the plan. ("Note": the introduction of video-guided radiotherapy will be placed in the next blog post, the specific role of the various images will be analyzed in detail.) ）

2. IHE framework-defined radiotherapy process:

Ihe-integrating the Healthcare Enterprise, which itself does not develop relevant standards, is a technical framework designed to improve the sharing of information between medical computer systems, by improving the level of interoperability between existing communication standards, such as DICOM and HL7, To meet the special clinical needs, to better serve the doctors and patients. It contains technical frameworks related to the field of radiotherapy (radiotherapy oncology).
The Ihe-radiotherapy Oncology framework is as follows:


Basically consistent with the above-mentioned process, the first is the CT scan to obtain the patient three-dimensional diagnostic data (here the data is diagnostic-grade CT data, and the subsequent treatment process mentioned in the KV-CBCT different, the next Boven introduction). In addition, the final appendix to the first part of the framework gives a detailed concept of the Geometry plan formulation (geometric Planner) and dosage plan formulation (dosimetric Planner) mentioned above:

From the IoD object definition perspective of DICOM-RT, the difference betweengeometric plan and dosimetric plan is as follows:

In general, it can be easily understood as
- geometricplan, which contains relevant positioning information, such as center Point (isocenter), ray angle (beam angle), field size, etc. This part of the concept in the previous post DICOM-RT: The coordinate system of the radiotherapy system Dicom-rt coordinate systems are mentioned;
- dosimetric Plan (dosage plan), which contains radiation dose information, such as dosage prescriptions (prescription), dose matrix (dose matrix), Statistical model algorithm (modeling algorithm), etc.

Participating roles:

As shown (radiotherapy treatment WorkFlow (TRWF)), each link requires a different person to participate, including: Oncologist, analog location technician, dosimetry, physiotherapist, therapist, nurse , etc. The exact responsibilities of each role may not be strictly defined, as there might be cross-cutting and co-ordination of each other during the execution, and here is a brief overview:

• Radiation Oncologist(hereinafter referred to as oncologist, commonly referred to as physicians ), physicians are professionally trained oncologists ( which should belong to the internal medicine bar, not very clear ), Responsible for the treatment of cancer patients, through communication with patients to understand, agreed the best treatment plan.
• radiation physicist(that is, the radiation Physics Division ), the physics division has in-depth research in tumor radiology physics, Plan to ensure that the linear accelerator (that is, the source of radiation that kills cancer cells) outputs an accurate dose of radiation and simulates the receiving dose of the cancerous part of the patient.
• dosimetrist( dosimetry ) will require a dose division to assist the physiotherapist during the planning process to ensure that the dosage is consistent with the prescriptions prescribed by the physician.
• Technician(technician, mainly including analog location technician and treatment technician ). The simulation location technician is the operator in the diagnosis CT scan of the patient, needs the skilled operation CT scanning equipment, completes the control of the door control and the movement degree, ensures the collection data is clear and reliable; The treatment technician is responsible for accurate positioning of the cancer patients, exact matching of the target area and correct operation of the linear accelerator, It is also responsible for real-time monitoring of the actual patient dose status in the treatment process, to ensure that the treatment process in strict accordance with the plan, abnormal presence of timely intervention to stop treatment.
• nurses , in each link may have the relevant medical staff to assist, do a good job of patient guidance, information registration, treatment status feedback, as well as treatment follow-up work.

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Date: 2016-04-10

DICOM-RT: Radiotherapy process and participatory roles