• Cancer medicine · Nov 2019

    Thyroid dose-volume thresholds for the risk of radiation-related hypothyroidism in nasopharyngeal carcinoma treated with intensity-modulated radiotherapy-A single-institution study.

    • Cheng-Long Huang, Hong-Wen Tan, Rui Guo, Yuan Zhang, Hao Peng, Liang Peng, Ai-Hua Lin, Yan-Ping Mao, Ying Sun, Jun Ma, and Ling-Long Tang.
    • Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong Key Laboratory of Nasopharyngeal Carcinoma Diagnosis and Therapy, Guangzhou, People's Republic of China.
    • Cancer Med. 2019 Nov 1; 8 (16): 6887-6893.

    BackgroundTo identify thyroid dose-volume thresholds for radiotherapy (RT)-related hypothyroidism (HT) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated RT (IMRT). In this way, we desired to guide the design of treatment plans and, finally, lower HT prevalence.MethodsIn total, 345 NPC patients treated with IMRT were evaluated retrospectively during a median follow-up of 45.2 (range, 11.3-64.9) months. Serum-based assessments of thyroid function before and after IMRT were monitored periodically. Thyroid dose-volume parameters were analyzed for their association with HT risk.ResultsIn total, 44.1% of patients (152/345) developed primary HT. Analyses of thyroid dose-volume parameters identified a stringent dose-volume histogram (DVH) threshold defined by V25Gy (the percentage thyroid volume that receives >25 Gy, not the absolute volume) ≤60%, V35Gy  ≤ 55%, and V45Gy  ≤ 45%. Patients whose thyroid DVHs satisfied these constraints had a lower prevalence of 2-year HT compared with the overall prevalence (13.2% vs 25.8%, P < .001). Another DVH was defined by V25Gy  > 95%, V35Gy  > 90%, and V45Gy  > 75%, and patients whose thyroid DVHs satisfied with these constraints had a higher prevalence of 2-year HT than the overall incidence (36.0% vs 25.8%, P < .001).ConclusionWe recommend V25Gy  ≤ 60%, V35Gy  ≤ 55%, and V45Gy  ≤ 45% as the "stringent" DVH line, and V25Gy  > 95%, V35Gy  > 90%, and V45Gy  > 75% as the "inhibition" DVH line, under the precondition of not compromising the target coverage. These findings could help in the design of individual treatment plans and, eventually, to lowering of HT prevalence.© 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

      Pubmed     Free full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…