Risk Factors Causing Hypothyroidism in Patients With Head and Neck Cancer After Radiotherapy Using SIB-VMAT

Area of Science:

• Oncology
• Radiation Oncology
• Endocrinology

Background:

• Head and neck cancer patients undergoing radiotherapy are at risk for radiation-induced hypothyroidism.
• Simultaneous integrated boost-volumetric modulated arc therapy (SIB-VMAT) is a common radiotherapy technique for head and neck cancers.
• Understanding hypothyroidism incidence and risk factors is crucial for patient management.

Purpose of the Study:

• To evaluate the incidence of radiation-induced hypothyroidism in head and neck cancer patients treated with SIB-VMAT.
• To identify clinical and dosimetric risk factors associated with hypothyroidism development.
• To explore the utility of radiation dose-volume parameters in predicting this complication.

Main Methods:

• Retrospective analysis of 86 head and neck cancer patients treated with SIB-VMAT.
• Evaluation of the incidence of grade 2 or higher hypothyroidism.
• Correlation analysis between hypothyroidism and clinical factors, as well as thyroid dose-volume parameters (e.g., VS60, VS70, VS60EQD2, VS70EQD2).

Main Results:

• 36.0% of patients developed grade 2 hypothyroidism within a median follow-up of 17 months.
• No patients experienced grade 3 or higher hypothyroidism.
• Significant associations were found between hypothyroidism and thyroid volume, VS60, VS70, VS60EQD2, and VS70EQD2.

Conclusions:

• Radiation-induced hypothyroidism is a frequent complication in head and neck cancer patients treated with SIB-VMAT.
• Thyroid dose-volume parameters are valuable predictors for preventing radiation-induced hypothyroidism.
• Further research into optimizing radiotherapy planning to spare the thyroid gland is warranted.