Talk:IHERO UseCase Prescription Automatation

What can currently be found in DICOM
The DICOM Standard currently has a Prescription Module with specific elements that are used to convey some of the Dosimetric Intent. An attempt to summarize some of these are listed below, but for full information, it is the RT Prescription Module, Sec C.8.8.10 in DICOM PS3.3 - 2007:
Similarly, there is an RT Patient Setup Module (relating to imaging and patient setup). This can be found in in the RT Patient Setup Module, Sec 8.8.12 in DICOM PS3.3 - 2007

Relating to Dosimetric Intent
Dose Reference Structure Type (Point, ROI, Volume, Coordinates, Site)
Referenced ROI Number (if an ROI or a Volume is being prescribed to, this identifies which ROI or Volume)
Dose Reference Point Coordinates (if it is coordinates being prescribed to, e.g. if the Physician reviewed the CT and picked a pixel on the screen as the point to prescribe to).
Nominal Prior Dose (to this particular "thing" that is being referenced)
Dose Reference Type (Target, Organ at Risk)
Constraint Weight
Delivery Warning Dose
Delivery Maximum Dose
Target Minimum Dose
Target Prescription Dose
Target Maximum Dose
Target Underdose Volume Fraction (Percent allowed to be underdosed)
Organ at Risk Full-volume Dose
Organ at Risk Limit Dose
Organ at Risk Maximum Dose
Organ at Risk Overdose Volume Fraction (Percent allowed to be overdosed)

Some of what can be found in a particular commercial system
The following are abstracted from a particular commercial system, and are only intended as an aid in enumerating the particular "elements". These have some overlap with the DICOM RT Prescription mentioned above.

Site (Anatomic Name, Structure Name?)
Radiation Type (Photons, Protons, Electrons)
Technique (AP/PA, Four Field Box)
Modality (MV Photons with Energy, Ortho, Electrons with Energy)

Dose Specification Location (90%iso, D-Max, Depthdose, Isocenter, Isodose, Mid-plane, Plan, Point, Tumor)
Dose Specification Value (100, 90, 1)
Dose Specification Units/dimensionality (Percentage, centimeters)

Total Dose (in units of Gray or Cobalt Gray Equivalent)
Number of Fractions
Dose Per Fraction
(note that Total Dose = Dose Per Fraction * Number of Fractions, so there is redundant information)
Dose Semantics (Physical Dose vs. Biologically Equivalent Dose)

Fractionation Pattern (Start, End (# of times), Times Per Day, Daily, Weekly, Bi-Weekly,Every (n) Days, inclusion of Saturday,and/or Sunday, and/or Holidays

Dose Limits (Total Cumulative) in units of Gray, e.g. When additional radiation may accumulate from a separately irradiated Site.

Pattern?
Comment

Status [change] (Pending, Approved, On Hold, Closed, Completed, Exclusive, Voided)
Status [change] Date/Time
Status changer (a person's name, username, initials...whatever identifies the person who made/authorized the change in status)

Relating to Patient Setup

The RT Patient Setup module refers to Patient Position
Setup Images
Fixation Devices
Shielding Devices

Setup Technique where the Setup Device Type may be one of the following:
LASER_POINTER
DISTANCE_METER
TABLE_HEIGHT
MECHANICAL_PTR
ARC

Motion Synchronization and Respiratory Motion Compensation (Gating)
NONE
BREATH_HOLD
REALTIME = image acquisition shorter than respiratory cycle
GATING = Prospective gating
TRACKING = prospective through- plane or in-plane motion tracking
PHASE_ORDERING = prospective phase ordering
PHASE_RESCANNING = prospective techniques, such as real-time averaging, diminishing variance and motion adaptive gating
RETROSPECTIVE = retrospective gating
CORRECTION = retrospective image correction

Comments on what might also be needed
For a number of the kinds of information mentioned above, it will also be of considerable value to know if there are particular defined values that should be used, e.g. if in attempting to describe a target, one would want to use defined names such as PTV, CTV, GTV. Many of these do have definitions in the DICOM standard, and not all were enumerated completely in the above... In some cases the level of detail above is not critical to the description of the use case, but I hope that this detail will be helpful in guiding the editors/authors of the use case.

DICOM Information Objects under development (DICOM RT, the Next Generation)

There is work going on in DICOM WG-7 (Radiation Therapy) to separate out the Physician Intent and Patient Setup from their current location in the DICOM objects.

Information regarding the proposed content for those new DICOM objects will get posted here with the intent to get feedback regarding whether that content will be sufficient for meeting this Use Case and perhaps more importantly to get help in identifying what is missing from the proposed content that will be necessary for fulfilling this Use Case.