Brain radiotherapy and dorsal vagal complex irradiation: A new organ at risk to decrease radiation-induced nausea and...

Area of Science:

• Radiation Oncology
• Neuroscience
• Medical Physics

Background:

• Nausea is a frequent side effect of radiotherapy for benign brain tumors.
• The dorsal vagal complex (DVC) in the brainstem is recognized as a key center for nausea and vomiting.
• Understanding dose-response relationships is crucial for optimizing radiation therapy planning.

Purpose of the Study:

• To investigate the association between the mean radiation dose delivered to the DVC and the occurrence of nausea in patients treated for benign brain tumors.
• To identify a potential dose threshold for the DVC that correlates with radiation-induced nausea.

Main Methods:

• Retrospective analysis of 102 patients with benign brain tumors treated with intensity-modulated radiotherapy.
• DVC and brainstem (BS) delineation using MRI T1 sequences with gadolinium contrast.
• Statistical analysis to correlate mean DVC and BS doses with nausea incidence.

Main Results:

• Nausea occurred in 39.2% of patients, with a higher incidence in younger patients.
• A significant association was found between mean DVC dose and nausea (p < 10^-4).
• The optimal DVC dose threshold was 8.82 Gy, with nausea risk increasing from 16% to 62% above this threshold.

Conclusions:

• Mean DVC radiation dose is a significant predictor of radiation-induced nausea.
• A DVC dose constraint below 8.82 Gy is proposed to mitigate nausea.
• Prospective studies are needed to validate this dose constraint in clinical practice.