Yoshimura N, Fujiwara M, Igeta M, Suzuki H, Kunimoto R, Terada T, Shinoda Y, Nakamura M, Fukutake J, Takaki H, Yamakado K. Risk Factors Causing Hypothyroidism in Patients With Head and Neck Cancer After Radiotherapy Using SIB-VMAT.
Anticancer Res 2024;
44:323-329. [PMID:
38159971 DOI:
10.21873/anticanres.16815]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024]
Abstract
BACKGROUND/AIM
We evaluated the incidence of radiation-induced hypothyroidism and its risk factors in patients with head and neck cancer who underwent radiotherapy using simultaneous integrated boost-volumetric-modulated arc therapy (SIB-VMAT).
PATIENTS AND METHODS
This retrospective study included 86 patients who received definitive radiotherapy using SIB-VMAT for head and neck cancer. The incidence of ≥ grade 2 hypothyroidism was evaluated. We also evaluated the relationships between hypothyroidism development and clinical factors and thyroid dose-volume parameters.
RESULTS
During a median follow-up period of 17 months (range=3-65 months), 31 patients (36.0%, 31/86) developed grade 2 hypothyroidism requiring hormone replacement therapy. No patients experienced ≥ grade 3 hypothyroidism. The cumulative incidences of hypothyroidism at 1 and 2 years after radiation therapy were 24.5% and 38.7%, respectively, with a median onset time of 10.0 months (range=3.0-35.0 months). Thyroid volume (p=0.003), volume of the thyroid spared at 60 Gy (VS60; cut-off value, 5.16 ml; p=0.009), VS70 (cut-off value, 8.0 ml; p=0.007), VS60 equivalent dose in 2 Gy fraction (EQD2; cut-off value, 7.78 ml; p=0.001), and VS70EQD2 (cut-off value, 10.59 ml; p=0.008) were significantly associated with the development of radiation-induced hypothyroidism.
CONCLUSION
Radiation-induced hypothyroidism is not rare in patients with head and neck cancer undergoing radiotherapy using SIB-VMAT. Radiation dose-volume parameters detected in this study may be useful indicators to prevent this complication.
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