Background

Radiotherapy is a directed treatment that targets a specific areas or volumes in or on the body. The RadiotherapyVolume profile describes these areas or volumes in terms of a BodyStructure resource. Using a standalone resource permits reuse of the same body volume in planning, executing, and reporting a radiotherapy treatment, as opposed to repeating the same elements in multiple places.

The code list of anatomic structures and location qualifiers applicable to RadiotherapyVolume follows the recommendations of the American Association of Physicists in Medicine (AAPM) Task Group 263 report on Standardizing Nomenclatures in Radiation Oncology. Volumes are further classified according to their type, including the following Burnet et al., 2004:

• Gross tumour volume (GTV) - what can be seen, palpated or imaged
• Clinical target volume (CTV) - the GTV plus a margin accounting for sub-clinical disease spread which therefore cannot be fully imaged
• Planning target volume (PTV) - a geometric concept designed to ensure that the radiotherapy dose is actually delivered to the CTV
• Organs at Risk (OR or OAR) - critical normal tissue structures that should be protected against excessive radiation

An additional volume types referenced by ICRU62 is the term Internal Target Volume (ITV), represents a volume encompassing the CTV with an internal margin compensating for patient movement. As defined by Ezhil et al the Internal Gross Tumor Volume (IGTV) represents the GTV with an internal margin to compensate for all movements.

Usage

The treatment location should be expressed using the anatomical concepts in the American Association of Physicists in Medicine (AAPM) Task Group 263 report on Standardizing Nomenclatures in Radiation Oncology, expressed using SNOMEDCT. The mapping from AAPM TG263 concepts to SNOMEDCT codes (RadiotherapyTreatmentLocationVS) and qualifiers (RadiotherapyTreatmentLocationQualifierVS) can be found in this spreadsheet. An excerpt of this spreadsheet is shown below. For example, if the treatment location was the Left Breast, with TG263 primary name Breast_L, the location would be expressed by using the SNOMEDCT 76752008 (Breast structure (body structure)) for location, and 7771000 (Left) for the locationQualifier.

Limitations

A known limitation of the RadiotherapyVolume is that it accepts only one coded location. This limitation stems from the base BodyStructure resource. As a result, a compound volume (such as prostate plus seminal vesicles) cannot be represented. If this presents a serious limitation in practice, an extension with additional pairs (location, location qualifiers) will be required.

Conformance

BodyStructure resources whose morphology has a code from the value set RadiotherapyVolumeTypeVS MUST conform to this profile. Beyond this requirement, a producer of resources SHOULD ensure that any resource instance associated with an in-scope patient that would reasonably be expected to conform to this profile SHOULD be published in this form. Any resource intended to conform to this profile SHOULD populate meta.profile accordingly.

• Text Summary
• Differential Table
• Snapshot Table
• Snapshot Table (Must Support)
• All

This structure is derived from BodyStructure

Name	Flags	Card.	Type	Description & Constraints
BodyStructure	I	0..*	BodyStructure	Specific and identified anatomical structure mcode-description-or-id-required: One of description or identifier MUST be present
Slices for identifier	S	0..*	Identifier	Volume Identifier Slice: Unordered, Open by value:use
identifier:displayName	S	0..1	Identifier	Bodystructure identifier
use		1..1	code	usual | official | temp | secondary | old (If known) Required Pattern: usual
value	S	1..1	string	The value that is unique
morphology	S	0..1	CodeableConcept	Type of Radiotherapy Volume Binding: Radiotherapy Volume Type Value Set (extensible)
location	S	0..1	CodeableConcept	Body Location Code. Binding: Radiotherapy Treatment Location Value Set (required)
locationQualifier	S	0..*	CodeableConcept	Qualifiers on location used to specify a TG263 body structure comprising the irradiated volume. Binding: Radiotherapy Treatment Location Qualifier Value Set (required)
description	S	0..1	string	Volume Description
patient	S	1..1	Reference(Cancer Patient Profile)	Who this is about
Documentation for this format

Name	Flags	Card.	Type	Description & Constraints
BodyStructure	I	0..*	BodyStructure	Specific and identified anatomical structure mcode-description-or-id-required: One of description or identifier MUST be present
id	Σ	0..1	string	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: CommonLanguages (preferred) Max Binding: AllLanguages: A human language.
text		0..1	Narrative	Text summary of the resource, for human interpretation
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
Slices for identifier	SΣ	0..*	Identifier	Volume Identifier Slice: Unordered, Open by value:use
identifier:displayName	SΣ	0..1	Identifier	Bodystructure identifier
id		0..1	string	Unique id for inter-element referencing
Slices for extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
use	?!Σ	1..1	code	usual | official | temp | secondary | old (If known) Binding: IdentifierUse (required): Identifies the purpose for this identifier, if known . Required Pattern: usual
type	Σ	0..1	CodeableConcept	Description of identifier Binding: Identifier Type Codes (extensible): A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.
system	Σ	0..1	uri	The namespace for the identifier value Example General: http://www.acme.com/identifiers/patient
value	SΣ	1..1	string	The value that is unique Example General: 123456
period	Σ	0..1	Period	Time period when id is/was valid for use
assigner	Σ	0..1	Reference(Organization)	Organization that issued id (may be just text)
active	?!Σ	0..1	boolean	Whether this record is in active use
morphology	SΣ	0..1	CodeableConcept	Type of Radiotherapy Volume Binding: Radiotherapy Volume Type Value Set (extensible)
location	SΣ	0..1	CodeableConcept	Body Location Code. Binding: Radiotherapy Treatment Location Value Set (required)
locationQualifier	S	0..*	CodeableConcept	Qualifiers on location used to specify a TG263 body structure comprising the irradiated volume. Binding: Radiotherapy Treatment Location Qualifier Value Set (required)
description	SΣ	0..1	string	Volume Description
image		0..*	Attachment	Attached images
patient	SΣ	1..1	Reference(Cancer Patient Profile)	Who this is about
Documentation for this format

Name	Flags	Card.	Type	Description & Constraints
BodyStructure	I	0..*	BodyStructure	Specific and identified anatomical structure mcode-description-or-id-required: One of description or identifier MUST be present
Slices for identifier	Σ	0..*	Identifier	Volume Identifier Slice: Unordered, Open by value:use
identifier:displayName	Σ	0..1	Identifier	Bodystructure identifier
value	Σ	1..1	string	The value that is unique
morphology	Σ	0..1	CodeableConcept	Type of Radiotherapy Volume Binding: Radiotherapy Volume Type Value Set (extensible)
location	Σ	0..1	CodeableConcept	Body Location Code. Binding: Radiotherapy Treatment Location Value Set (required)
locationQualifier		0..*	CodeableConcept	Qualifiers on location used to specify a TG263 body structure comprising the irradiated volume. Binding: Radiotherapy Treatment Location Qualifier Value Set (required)
description	Σ	0..1	string	Volume Description
patient	Σ	1..1	Reference(Cancer Patient Profile)	Who this is about
Documentation for this format

This structure is derived from BodyStructure

Summary

Mandatory: 0 element (2 nested mandatory elements)
Must-Support: 8 elements

Structures

This structure refers to these other structures:

• Cancer Patient Profile (http://hl7.org/fhir/us/mcode/StructureDefinition/mcode-cancer-patient)

Slices

This structure defines the following Slices:

• The element BodyStructure.identifier is sliced based on the value of value:use

Differential View

This structure is derived from BodyStructure

Name	Flags	Card.	Type	Description & Constraints
BodyStructure	I	0..*	BodyStructure	Specific and identified anatomical structure mcode-description-or-id-required: One of description or identifier MUST be present
Slices for identifier	S	0..*	Identifier	Volume Identifier Slice: Unordered, Open by value:use
identifier:displayName	S	0..1	Identifier	Bodystructure identifier
use		1..1	code	usual | official | temp | secondary | old (If known) Required Pattern: usual
value	S	1..1	string	The value that is unique
morphology	S	0..1	CodeableConcept	Type of Radiotherapy Volume Binding: Radiotherapy Volume Type Value Set (extensible)
location	S	0..1	CodeableConcept	Body Location Code. Binding: Radiotherapy Treatment Location Value Set (required)
locationQualifier	S	0..*	CodeableConcept	Qualifiers on location used to specify a TG263 body structure comprising the irradiated volume. Binding: Radiotherapy Treatment Location Qualifier Value Set (required)
description	S	0..1	string	Volume Description
patient	S	1..1	Reference(Cancer Patient Profile)	Who this is about
Documentation for this format

Snapshot View

Name	Flags	Card.	Type	Description & Constraints
BodyStructure	I	0..*	BodyStructure	Specific and identified anatomical structure mcode-description-or-id-required: One of description or identifier MUST be present
id	Σ	0..1	string	Logical id of this artifact
meta	Σ	0..1	Meta	Metadata about the resource
implicitRules	?!Σ	0..1	uri	A set of rules under which this content was created
language		0..1	code	Language of the resource content Binding: CommonLanguages (preferred) Max Binding: AllLanguages: A human language.
text		0..1	Narrative	Text summary of the resource, for human interpretation
contained		0..*	Resource	Contained, inline Resources
extension		0..*	Extension	Additional content defined by implementations
modifierExtension	?!	0..*	Extension	Extensions that cannot be ignored
Slices for identifier	SΣ	0..*	Identifier	Volume Identifier Slice: Unordered, Open by value:use
identifier:displayName	SΣ	0..1	Identifier	Bodystructure identifier
id		0..1	string	Unique id for inter-element referencing
Slices for extension		0..*	Extension	Additional content defined by implementations Slice: Unordered, Open by value:url
use	?!Σ	1..1	code	usual | official | temp | secondary | old (If known) Binding: IdentifierUse (required): Identifies the purpose for this identifier, if known . Required Pattern: usual
type	Σ	0..1	CodeableConcept	Description of identifier Binding: Identifier Type Codes (extensible): A coded type for an identifier that can be used to determine which identifier to use for a specific purpose.
system	Σ	0..1	uri	The namespace for the identifier value Example General: http://www.acme.com/identifiers/patient
value	SΣ	1..1	string	The value that is unique Example General: 123456
period	Σ	0..1	Period	Time period when id is/was valid for use
assigner	Σ	0..1	Reference(Organization)	Organization that issued id (may be just text)
active	?!Σ	0..1	boolean	Whether this record is in active use
morphology	SΣ	0..1	CodeableConcept	Type of Radiotherapy Volume Binding: Radiotherapy Volume Type Value Set (extensible)
location	SΣ	0..1	CodeableConcept	Body Location Code. Binding: Radiotherapy Treatment Location Value Set (required)
locationQualifier	S	0..*	CodeableConcept	Qualifiers on location used to specify a TG263 body structure comprising the irradiated volume. Binding: Radiotherapy Treatment Location Qualifier Value Set (required)
description	SΣ	0..1	string	Volume Description
image		0..*	Attachment	Attached images
patient	SΣ	1..1	Reference(Cancer Patient Profile)	Who this is about
Documentation for this format