Related Experiment Video
Updated: May 12, 2026

PET and MRI Guided Irradiation of a Glioblastoma Rat Model Using a Micro-irradiator
Published on: December 28, 2017
Development of a biological at-risk volume using apparent diffusion coefficient for parotid-sparing radiation therapy
Katelyn Cahill1,2, Catriona Hargrave3,4, Patrick O'Connor1,5
1Adem Crosby Centre-Radiation Oncology, Sunshine Coast University Hospital, Birtinya, QLD 4575, Australia.
This study shows that apparent diffusion coefficient (ADC) thresholds can identify radiosensitive areas in the parotid gland (PG) for head and neck cancer patients, potentially reducing xerostomia toxicity.
Area of Science:
- Radiotherapy
- Medical Imaging
- Oncology
Background:
- Xerostomia (dry mouth) significantly impacts head and neck cancer patients' quality of life.
- Diffusion-weighted MRI and apparent diffusion coefficient (ADC) mapping offer potential for identifying radiosensitive tissues.
Purpose of the Study:
- To assess the feasibility of using ADC percentile thresholds to define a biological at-risk volume (BRV) within the parotid gland (PG).
- To evaluate the spatial distribution of this BRV across the PG.
Main Methods:
- Retrospective analysis of diffusion-weighted MRI data.
- Image registration between planning CT and MRI-simulation for accurate contouring.
- Histogram analysis using 20th, 30th, and 50th percentile ADC values to generate BRV.
- Division of the PG into 8 anatomical sectors to analyze BRV distribution.
Main Results:
- The 20th and 30th percentile ADC values effectively defined the BRV within the PG.
- BRV distribution was predominantly observed in the superolateral sectors of the PG.
Conclusions:
- ADC percentile thresholds can delineate a functional, radiosensitive region within the PG.
- This BRV is favorably located for potential sparing during radiotherapy dose optimization, aiming to reduce xerostomia.
More Related Videos
08:25Radiation Planning Assistant - A Streamlined, Fully Automated Radiotherapy Treatment Planning System
Published on: April 11, 2018
07:57Positron Emission Tomography-based Dose Painting Radiation Therapy in a Glioblastoma Rat Model using the Small Animal Radiation Research Platform
Published on: March 24, 2022
Related Concept Videos
Biological Effects of Radiation
Types of Biopharmaceutical Studies: Controlled and Non-Controlled Approaches
Non-controlled studies, commonly employed for initial exploration, lack a control group, rendering them susceptible to biases and external influences. In contrast, controlled...
Toxicity Testing in Animals