Related Experiment Video
Updated: Jun 20, 2026
09:10
Digital Hybrid Model Preparation for Virtual Planning of Reconstructive Dentoalveolar Surgical Procedures
Published on: August 5, 2021
[Help for delineation: what kind of tools?]
Y Pointreau1, G Bera, I Barillot
1Clinique d'Oncologie Radiothérapie, Centre Henry-S-Kaplan, CHU Bretonneau, 37044 Tours cedex 9, France.
Summary
Radiotherapy planning has advanced with new techniques, but target volume delineation variations remain a challenge. This paper presents key recommendations to standardize these volumes for improved patient outcomes.
Area of Science:
- Medical Physics
- Radiation Oncology
Background:
- Recent advancements in radiotherapy techniques like conformational radiotherapy, intensity-modulated radiation therapy, and stereotactic radiation therapy necessitate precise target volume definition.
- International Commission on Radiation Units and Measurements (ICRU) reports 50 and 62 provide recommendations for target volume definition but lack specific guidelines for delineation.
- Intra- and interobserver variations in target volume delineation are significant sources of uncertainty impacting radiotherapy outcomes.
Purpose of the Study:
- To present the main recommendations for standardizing target volume delineation in radiotherapy planning.
- To address the critical issue of observer variability in defining clinical target volumes (CTVs) and planning target volumes (PTVs).
Main Methods:
- Review of existing guidelines and atlases for radiotherapy target volume delineation.
- Analysis of common practices and sources of variation in delineation processes.
- Synthesis of recommendations aimed at reducing interobserver variability.
Main Results:
- Identification of key areas contributing to delineation uncertainties.
- Presentation of a consolidated set of recommendations for consistent volume definition.
- Highlighting the importance of standardized protocols and training.
Conclusions:
- Standardized target volume delineation is crucial for reducing uncertainties in radiotherapy planning.
- Implementing the presented recommendations can help homogenize delineation practices across different institutions.
- Improved consistency in target volume definition is expected to enhance the precision and effectiveness of radiation therapy.
Related Concept Videos
01:26Profile Leveling and Cross Sections
Profile leveling and cross-sections are surveying methods used to determine and document terrain elevations for infrastructure projects such as highways, railroads, canals, and pipelines. These methods provide data for earthwork planning and alignment of proposed routes. Profile leveling involves measuring elevations along a fixed line to create a vertical terrain profile. A surveyor sets up a leveling instrument at the benchmark (BM) and records a backsight (BS) to determine the instrument's...
01:18Leveling Equipment
As leveling involves measuring vertical distances relative to a horizontal line of sight, it requires a graduated rod, called a level rod, for vertical measurements and an instrument called a level for a horizontal sight line. A level includes a high-powered telescope with a mechanism for leveling to ensure the line of sight is horizontal when the bubble in the spirit level is centered. Leveling rods, made of wood, metal, or fiberglass, are graduated in feet or meters and commonly used in two-...
01:12Design Example: Marking Boundaries of a Site Using a Compass
Marking site boundaries using a compass is a precise surveying technique that ensures the accuracy of boundary delineation. The process begins by using provided site details, including the bearings and lengths of each boundary line. The initial step involves calculating latitudes and departures for all sides of the site. This computation verifies that the traverse is free of errors, ensuring a closed and accurate boundary.The process starts at a known point, such as Point A, which is often...
01:12Differential Leveling
Differential leveling is a precise method in surveying used to determine the elevation difference between two points. Its primary goal is to establish accurate vertical measurements to create level surfaces or grade lines critical for designing and constructing infrastructures such as roads, bridges, and buildings.The procedure for differential leveling begins with setting up and leveling the instrument at a point where the benchmark can be seen. The level rod is held on the benchmark (BM), and...
01:19Design Example: Maintaining Level of an Embankment
Constructing a roadway embankment over uneven terrain requires precise leveling to ensure stability and proper drainage. Surveyors use a leveling instrument and staff to calculate ground elevations and determine the required fill material at each point along the embankment alignment.The process begins by positioning a leveling instrument near a benchmark with a known elevation. A backsight reading establishes the instrument height, which serves as a reference for subsequent measurements. A...
01:12Taping Over Different Ground Profiles
Taping over varying ground profiles requires careful adaptation to achieve accurate measurements. On smooth, level ground with minimal vegetation, the tape can rest directly on the ground. Here, the taping team, typically consisting of a head and a rear tapeman, coordinates their positions with clear communication. The rear tapeman holds the tape at the starting point and guides the head tapeman toward a range pole placed beyond the endpoint, using hand or voice signals to ensure alignment.On...