ISO/TR 24290:2023

Health informatics - Datasets and data structure for clinical and biological evaluation metrics in radiotherapy

This document reports on the datasets and a data structure for reporting clinical and biological evaluation metrics (CBEMs). The reporting of radiation dose estimates is outside the scope of this document. This document is applicable to CBEMs for external-beam radiation therapy (EBRT) modalities, but not CBEMs for brachytherapy or molecular radiotherapy. Various types of radiotherapy treatment modalities are available for cancer care. Consequently, there is a growing awareness of the need for objective schemes that will contribute to enable the selection of an appropriate radiotherapy treatment modality for individual patients. The use of CBEMs, the metrics associated with a certain radiotherapy treatment plan for a patient, is attracting attention for clinical purposes in the field of EBRT. In anticipation of the clinical use of CBEMs, the importance of research on clinical and scientific aspects of CBEMs is increasing, in concert with the importance of establishing a standardized data format for reporting of specifics of a CBEM.

Informatique de santé — Jeux de données et structure de données pour les métriques d'évaluation clinique et biologique en radiothérapie

General Information

• Status: Published
• Publication Date: 29-May-2023
• ICS: 35.240.80 - IT applications in health care technology
• Technical Committee: ISO/TC 215 - Health informatics
• Drafting Committee: ISO/TC 215/WG 2 - Systems and Device Interoperability
• Current Stage: 6060 - International Standard published
• Start Date: 30-May-2023
• Completion Date: 30-May-2023

Overview

ISO/TR 24290:2023 - “Health informatics - Datasets and data structure for clinical and biological evaluation metrics in radiotherapy” defines a standardized dataset and data-structure approach for reporting clinical and biological evaluation metrics (CBEMs) used in external-beam radiation therapy (EBRT). The technical report focuses on enabling traceable, interoperable reporting of CBEM values (for example TCP - tumour control probability, and NTCP - normal tissue complication probability) and the metadata needed to interpret them. Reporting of radiation dose estimates and CBEMs for brachytherapy or molecular radiotherapy are explicitly outside the scope.

Key Topics

• Scope & applicability: CBEM reporting structure for EBRT modalities only; excludes dose-estimate reporting and non-EBRT radiotherapy types.
• Data structure & datasets: Recommended layout of a CBEM report, including hierarchical elements such as body part, region of interest (ROI), and associated data elements.
• Patient and treatment metadata: Patient condition information, treatment plan identifiers and treatment planning system (RTPS) context needed for reproducibility.
• CBEM information: Fields to describe the metric value, model version, assumptions, uncertainties, and any dose conversions performed (e.g., DVH adjustments and fractionation corrections).
• Traceability & transparency: Emphasis on documenting model definitions, limitations, non-dosimetric factors, and conversion steps so reported CBEMs are interpretable and comparable.
• Appendix support: Informative annex with example CBEM model and related data elements to guide implementation.
• Terminology & interoperability: Alignment with health informatics concepts (DICOM, DVH, RTPS, LOINC abbreviations included) and standardized terms.

Applications

• Enables standardized reporting of CBEMs for:
  • Clinical decision support - comparing treatment-plan CBEMs to help select an optimal EBRT modality for individual patients.
  • Clinical trials & research - consistent CBEM datasets for multicentre studies and model validation.
  • Software and vendor integration - harmonizing CBEM output from treatment planning systems and analytics tools.
  • Regulatory & quality assurance - improving auditability and reproducibility of model-based metrics.

Who should use this standard

• Medical physicists, radiation oncologists, and dosimetrists
• Health informatics specialists and standards implementers
• RTPS and clinical software vendors
• Clinical researchers designing radiotherapy trials or CBEM studies

Related standards

• DICOM (medical imaging interoperability)
• ICRU reports (CBEM concepts such as TCP/NTCP; e.g., ICRU 83)
• ISO/IEC terminology and health informatics guidance

ISO/TR 24290:2023 provides a practical, interoperable foundation for implementing transparent CBEM reporting in EBRT workflows, improving comparability, traceability and clinical utility of model-derived radiotherapy metrics.

Standards Content (Sample)

TECHNICAL ISO/TR
REPORT 24290
First edition
2023-05
Health informatics — Datasets
and data structure for clinical and
biological evaluation metrics in
radiotherapy
Informatique de santé — Jeux de données et structure de
données pour les métriques d'évaluation clinique et biologique en
radiothérapie
Reference number
© ISO 2023
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Abbreviated terms . 3
5 CBEMs in EBRT .4
5.1 General . 4
5.2 CBEMs . 4
5.3 Use case of CBEMs . 5
5.3.1 Selection of the EBRT modality . 5
5.3.2 Clinical trials . 5
5.4 Existing data format for CBEMs . 6
6 Datasets and data structure for a CBEM . 6
6.1 General . 6
6.2 Datasets and data structure . 6
6.2.1 Structure of the CBEM report . 6
6.2.2 Structure of the body part . 6
6.2.3 Patient condition information . 6
6.2.4 Treatment plan information. 7
6.2.5 CBEM information . 7
6.2.6 Comments on CBEM report . 9
Annex A (informative) Example of a CBEM model and related data elements .10
Bibliography .12
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 215, Health informatics.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
Radiotherapy or radiation therapy is a treatment method used mostly in cancer care. Due to rapid
technical advances of the radiotherapy treatment modalities, it is becoming increasingly important to
select an appropriate radiotherapy treatment modality for individual patients by considering patient
conditions and the resources that are required.
In the case of external-beam radiation therapy (EBRT), where the therapeutic radiation beams are
emitted from a machine outside the body of the patient, treatment planning is performed prior to
treatment. When selecting a treatment modality from among possible candidates, treatment plans are
made for the candidates, if necessary, and then the dosimetric indices and/or radiobiological metrics
corresponding to the treatment plans are compared.
Tumour control probability (TCP) and normal tissue complication probability (NTCP) are among
the metrics used in the comparisons. They are simple phenomenological models based on clinical
[12]
observations which are described in ICRU 83 as clinical and biological evaluation metrics (CBEMs),
along with other metrics such as equivalent uniform dose, conformity and homogeneity indices.
Recently, more sophisticated models incorporating non-dosimetric patient factors, spatial dose metrics
and -omics elements (e.g. radiomics and proteomics) have also received attention and some of them are
starting to be referred to in clinical trials in some countries.
For wider and safer use of CBEMs in clinical practice and clinical trials, it is important to provide
an effective framework for ensuring the traceability of calculated metrics. Standardization of data
formats for reporting calculated CBEMs is one possible way. However, no attention has been paid to
such standardization to date, while there is active research on new metrics or new models as well as
increasing attention to transparent reporting of developed models.
This document describes datasets and data structure for the reporting of CBEMs, especially of simple
model types of TCP and NTCP. Scientific aspects of reliability of CBEMs are not in the scope of this
document. Because of the variety of CBEM models, when an evaluated CBEM is to be reported and/
or referred to, it is important to report and/or refer to the value of the calculated CBEM along with
information about the CBEM model itself as well as with dose information and non-dosimetric factors
of the patient that are used in the calculation. It is also important to include descriptions about
uncertainties, underlying assumptions, limitations and situations for application of the CBEM model.
In general, the dose information of the treatment plan used in the calculations (dose-volume histogram
(DVH) in most cases) is converted to match the model definition; for instance, adjusting the differences
in fraction size between the plan of the patient and the reference fraction size of the CBEM model. This
means that the apparent values of the doses (e.g. maximum dose and mean dose) used in the calculation
are CBEM-model-specific. To ensure traceability, inclusion of the description about the process of
such dose conversions along with the value of the representative dose values would be a great help.
This document provides datasets and data structure for CBEM reporting by considering the above
mentioned aspects.
While this document is not intended to cover the reporting of CBEMs by contemporary sophisticated
models, the data structures described in this document can apply to the reporting of them as well.
v
TECHNICAL REPORT ISO/TR 24290:2023(E)
Health informatics — Datasets and data structure for
clinical and biological evaluation metrics in radiotherapy
1 Scope
This document reports on the datasets and a data structure for reporting clinical and biological
evaluation metrics (CBEMs). The reporting of radiation dose estimates is outside the scope of this
document.
This document is applicable to CBEMs for external-beam radiation therapy (EBRT) modalities, but not
CBEMs for brachytherapy or molecular radiotherapy.
Various types of radiotherapy treatment modalities are available for cancer care. Consequently, there
is a growing awareness of the need for objective schemes that will contribute to enable the selection of
an appropriate radiotherapy treatment modality for individual patients. The use of CBEMs, the metrics
associated with a certain radiotherapy treatment plan for a patient, is attracting attention for clinical
purposes in the field of EBRT. In anticipation of the clinical use of CBEMs, the importance of research on
clinical and scientific aspects of CBEMs is increasing, in concert with the importance of establishing a
standardized data format for reporting of specifics of a CBEM.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
data element
unit of data that is considered in context to be indivisible
Note 1 to entry: The definition states that a data element is “indivisible” in some context. This means it is possible
that a data element considered indivisible in one context (e.g. telephone number) can be divisible in another
context (e.g. country code, area code, local number).
[SOURCE: ISO/IEC 11179-1:2023, 3.3.4, modified — Example deleted.]
3.2
Digital Imaging and Communications in Medicine
DICOM
standard for the communication and management of medical imaging information and related data
Note 1 to entry: The DICOM Standard facilitates interoperability of medical imaging equipment.
Note 2 to entry: DICOM is defined in ISO 12052.
[SOURCE: ISO/IEC 39794-16:2021, 3.16]
3.3
dose fractionation
method of administration of radiation in which the absorbed dose is divided into two or more fractions
separated in time
[SOURCE: IEV ref 881-11-18]
3.4
dose-volume histogram
DVH
dose as a distribution-function or frequency-function over a specified volume
[SOURCE: ICRU 50, modified — Abbreviated term “DVH” added.]
3.5
endpoint
principal indicator(s) used for providing the evidence for clinical performance, effectiveness
or safety in a clinical investigation
[SOURCE: ISO 14155:2020, 3.22]
3.6
intensity-modulated radiation therapy
IMRT
treatment procedure requiring, in general, the coordinated control of photon or electron fluence, beam
orientation relative to the patient, and beam size of the external beam, either in a continuous or a
discrete manner, and as pre-determined by a treatment plan (3.12)
Note 1 to entry: The primary purpose of IMRT is to improve the conformity of the dose distribution to the planned
target volume, while minimizing dose to surrounding healthy tissue.
[SOURCE: IEC 60976:2016, 3.2.7]
3.7
numerical value equation
numerical quantity value equation
mathematical relation between numerical quantity values, based on a given quantity equation and
specified measurement units
[SOURCE: ISO/IEC Guide 99:2007, 1.25, modified — Examples deleted.]
3.8
radiotherapy
radiation therapy
therapy that uses ionizing radiation to kill cells and shrink pathological tissues
Note 1 to entry: Radiation may be delivered by a machine outside the body (external-beam radiation therapy),
or it may come from radioactive material placed in the body near cancer cells (brachytherapy) or from
radiopharmaceutical administered to the patient (molecular radiotherapy).
[SOURCE: ISO 12749-6:2020, 3.3.2]
3.9
radiotherapy treatment planning system
RTPS
device, usually a programmable electrical medical system including its associated peripherals, that is
used to simulate the application of radiation to a patient for a proposed radiotherapy treatment
Note 1 to entry: It usually, but not necessarily, provides estimations of absorbed dose distribution in human
tissue using a particular algorithm or algorithms. These algorithms provide simulations of radiation that is
typically from, but not necessarily limited to, medical electron accelerators, gamma beam therapy equipment, or
in brachytherapy from radioactive sources.
[SOURCE: IEC 62083:2009, 3.1.6]
3.10
region of interest
ROI
sub-dataset picked out from the entire dataset for a specific purpose
[SOURCE: ISO 20263:2017, 3.1.24]
3.11
relative biological effectiveness
RBE
ratio of the absorbed dose of a reference radiation to the absorbed dose of the radiation
of interest, generally X-ray or gamma ray, that produces the same level of biological effect
Note 1 to entry: The term should only be used in radiobiology.
[SOURCE: IEV ref 881-17-03]
3.12
treatment plan
all patient and dosimetric information that is intended for use by appropriately qualified persons
for the purpose of prescribing or administering radiotherapy (3.8), including any information to be
transmitted to other equipment
Note 1 to entry: A printed or plotted treatment plan is referred to as a treatment plan report.
[SOURCE: IEC 62083:2009, 3.1.8]
3.13
treatment planning
process of establishing the treatment plan (3.12)
[SOURCE: IEC 62083:2009, 3.1.9]
4 Abbreviated terms
CBEM clinical and biological evaluation metric
CI confidence interval
DICOM Digital Imaging and Communications in Medicine
DVH dose-volume histogram
EBRT external-beam radiation therapy
IMRT intensity-modulated radiation therapy
LOINC Logical Observation Identifiers Names and Codes (Regenstrief Institute, Inc.)
NTCP normal tissue complication probability
RBE relative biological effectiveness
ROI region of interest
RTPS radiotherapy treatment planning system
TCP tumour control probability
5 CBEMs in EBRT
5.1 General
EBRT is a form of radiotherapy for delivering a beam or beams of ionizing radiation from outside the
body of patients. There are several different types of modalities of EBRT (EBRT modality) regarding
beam types and ways of forming dose distributions in the patient body, each provided by a specific
device or system. For specific patients, a suitable EBRT modality is selected among those available by
considering the patient condition and the resources required. Recently, the use of CBEMs for treatment
plans of EBRT has been gaining attention in clinical practice and for research purposes.
5.2 CBEMs
[12]
In ICRU 83 , the concept of CBEM is described in the section of “Level 3 Reporting” for intensity-
modulated radiation therapy (IMRT). IMRT is one EBRT modality, however, the described concept of
[12]
the CBEM can also be applicable to other EBRT modalities. In ICRU 83 , TCP, NTCP and combination
metrics of TCP and NTCP are described. This document examines TCP and NTCP as CBEMs but does not
examine combination metrics of these two.
The CBEM is a metric which is associated with a treatment plan. Multiple CBEMs can be associated with
one treatment plan, e.g. on metrics for different endpoints and/or by different CBEM models.
A schematic figure of the calculation process of a CBEM is shown in Figure 1. A CBEM is calculated
using a CBEM model which is expressed as one or multiple numerical value equations. The input to the
equations is the radiation dose information of a region of interest (ROI) for a treatment plan, which
corresponds to the definition of the CBEM model. In particular cases, it can be multiple ROIs. If the
model requires information regarding patient factors, this is also input for the calculations.
Figure 1 — Schematic of the CBEM calculation process
When the type of a CBEM is TCP, the ROI is the tissue volume that contains the tumour to be treated,
depending on the definition of the TCP model. When the type of a CBEM is NTCP, a ROI is one or plural
of normal tissues near the tumour. Radiation dose information of a ROI typically is either of the DVH, or
one or more dose-volume indices specific to the CBEM model. Examples of such values
...