Amygdala

Amygdala

The amygdala is a key structure of the limbic system and plays a central role in emotional processing, behavioural responses, learning, and memory. It is particularly involved in the recognition of emotionally relevant stimuli, such as fear and reward, and contributes to social behaviour, decision-making, and the formation of emotional memories. Together with the hippocampus and other limbic structures, the amygdala forms an important network that supports cognitive and emotional functioning.Because of its involvement in emotional regulation and cognition, there is growing interest in understanding the potential impact of radiation dose to the amygdala. Accurate delineation is therefore important in both clinical practice and research evaluating dose–effect relationships and treatment-related neurocognitive outcomes.

For contouring, the left and right amygdala should be delineated separately. Co-registration with a T1-weighted MRI is recommended to facilitate accurate identification of the structure.

The amygdala is a small, olive-shaped gray matter structure located in the anteromedial temporal lobe, with a typical volume of approximately 1–2 cm³. It is situated anterior to the hippocampus and forms part of the medial temporal lobe anatomy.

Key anatomical landmarks include:

• Anterior and medial borders: temporal lobe cortex.
• Posterior and inferior borders: temporal horn of the lateral ventricle and the hippocampus.
• Separation from the hippocampus: a thin white matter layer known as the alveus.
• Lateral border: white matter fibers of the temporal lobe.

The accompanying video demonstrates a step-by-step approach for identifying and contouring the amygdala using these anatomical landmarks. This educational content is intended to support consistent and accurate delineation in clinical practice and research.

Please site as follows:

Hofstede, D., Di Perri, D., Roelofs, E., Postma, A., Troost, E., & Eekers, D. EPTN International Neurological Contouring Atlas (INCA) instruction videos. CancerData, 2022. doi:10.17195/candat.2022.02.1