RT Beams Treatment Record

The RT Beams Treatment Record IOD is used for providing external beam treatment session records during a radiotherapy treatment course, with an optional treatment summary indicating the cumulative state of a treatment course.

The focus for this Radiotherapy Beams Treatment Record IOD (RT Beams Treatment Record IOD) is to address the requirements for transfer of treatment session reports generated by a treatment verification system duringn a course of external beam treatment, with optional cumulative summary information. It may also be used for transfer of treatment information during delivery.

Specific modules used in this IOD (all modules not marked optional are mandatory):

• RT General Treatment Record: General information like Treatment Date and Time (of last treatment), reference to the RT Plan delivered, reference to any significantly related Treatment Records.
• RT Patient Setup: Describes the positioning of the patient with respect to the treatment machine, along with any fixation devices and shilding devices, used. Optional Module.
• RT Treatment Machine Record: Contains a few attributes describing the treatment machine used.
• Measured Dose Reference Record: Set of doses measured during treatment delivery, summed over entire session. Optional Module.
• Calculated Dose Reference Record: Set of doses estimated for each treatment delivery. Optional Module.
• RT Beams Session Record: Large module (about 10 pages in standard) that documents the running conditions and outcome of a set of beams that are referenced from the RT Plan “this” treatment record refers to.
• RT Treatment Summary Record: Describes current status of the treatment in terms of planned/delivered fraction groups and measured doses. Optional Module.
• Curve (retired)

The RT Patient Setup Module is shortly described on the RT Plan page. The other modules are described in the sections below.

The only mandatory information here is Instance Number (which should identify the object instance), Treatment Date/Treatment Time and the Referenced RT Plan Sequence which references the RT Plan Object this Treatment Record is associated with. (further attribute explanations).

This is a short module describing the treatment machine in terms of “Treatment Machine Name”, Manufacturer, Institution Name/Address, Device Serial Number etc.

This module (surrounded by the Measured Dose Reference Sequence) documents any doses measured during treatment delivery,, e.g. Dose Units, Measured Dose Value, Measured Dose Type, Measured Dose Description. : further description of Dose Referencing.

This module documents some doses that were calculated, ie estimated (not measured) during each treatment delivery.

The RT Beams Session Record contains many informations about the treatment delivered so far. Except some general information like Operator Name, Number of Fractions Planned and Primary Dosimeter Unit, the treatment is documented here based on beams that were delivered, usually following a specific RT Plan. All this documentation is wrapped in the “Treatment Session Beam Sequence” which contains one item for each delivered (and therefore in this object) documented beam.

One item of the “Treatment Session Beam Sequence” contains the following information:

• General beam information: Beam Name/Description and Beam Type (STATIC or DYNAMIC(beam parameters change during delivery) as well as Radiation Type (PHOTON, ELECTRON, ….)
• Referenced Verification Image Sequence: References to any verification images shot during treatment delivery including meterset indication when images were acquired during delivery.
• Referenced Measured Dose Reference Sequence: Documents doses measured during treatment
• Referenced Calculated Dose Reference Sequence: Set of doses estimated for each treatment delivery.
• Source Axis Distance: Disctance (in mm) from radiation source to gantry rotation axis of equipment that was used for beam delivery
• Beam Limiting Dvice Lear Pairs Sequence: Total number and type of each leaf/jaw pair “active” during beam delivery.
• Referenced Patient Setup Number: References Patient Setup (Patient Setup Module also included by RT Treatment Record IOD)
• Wedges: Number, type, IDs, Angle and Orientation of wedges “active” during beam delivery
• Compensators: Compensator configuration during beam delivery
• Blocks: Block configuration during beam delivery
• Applicator: Applicator configuration during beam delivery
• Boli: Any Boli associated with Beam
• Current Fraction Number: The fraction number (from associated RT Plan) for this beam
• Treatment Termination: STatus (EV: NORMAL, OPERATOR, MACHINE, UNKNOWN) , Termination Code and Verification Status (EV: VERIFIED, VERIFIED_OVR, NOT_VERiFIED) for this treatment
• Metersets: Desired and actual Meterset stati for treatment machine
• Specified and Delivered Treatment Time
• Control Point Delivery Sequence: Control Point Information (see also RT Plan page, much of the data is replicated here, sometimes two-fold in desired and (additionally to RT Plan) actual delivered value for an attribute):
  • Treatment Control Point Date and Time
  • Specified and desired Meterset
  • Dose Rate Set and Delivered
  • Nominal Beam Energy and corresponding Unit (e.g. Megavolt, Mega electron-Volt)
  • Wedge Positions
  • Beam Limiting Device Information: Information about Leaf/Jaw-Positions. Beam Limiting Device Angle, Beam Limiting Device Rotation Direction
  • Gantry Angle and Rotation Direction
  • Beam Stopper Position (: What is a Beam Stopper?)
  • Patient Support Angle and Rotation Direction
  • Table Top position and movement information: Table Top Eccentric Axis Distance/Eccentric Angle/Eccentric Rotation Direction…
  • Override information: parameters which were overridden during the administration of the beam segment immediately prior to the current control point. Specified by element tag that was overriden, operator name who authorized this action and reason for overriding.

The only mandatory information in this module is the attribute “Current Treatment Status” which must have one of the following (enumerated) values: NOT_STARTED, ON_TREATMENT, ON_BREAK, SUSPEND, STOPPED, COMPLETED which each status being described further in the standard. further attributes