未分化型甲狀腺癌為一罕見且具高度侵犯性之惡性腫瘤，目前醫學界對於最適當之治療策略仍無共識。回顧過去文獻中發現，局部腫瘤減積手術並輔以術後放射治療，對於局部晚期之未分化型甲狀腺癌（Anaplastic thyroid cancer, ATC）可提供較佳之局部控制。然而，傳統放射治療因其技術上之限制，對位於此處之腫瘤在治療時很難達到有效且均勻之理想劑量分佈。近年來藉著放射治療技術之進步，例如籍由強度調控放射治療，可有效改善傳統治療之限制。而於使用強度調控放射治療時，若是輔以同步整合加量之技術，則可提供更佳之整體劑量分佈與生物效應。由於文獻中並無關於此種技術應用在局部晚期ATC之成果，我們在此報告一位患有局部晚期ATC之60歲女性，於本院行腫瘤減積手術後，輔以同步整合加量強度調控放射治療之成果，並回顧相關文獻。

Anaplastic thyroid cancer (ATC) is a rare malignancy with aggressive behavior and dismal outcome; the optimal treatment has not yet been determined. Debulky surgery followed by adjuvant radiotherapy (RT) has been reported to have better local control for locally advanced ATC. However, the technical limitations of conventional RT made it difficult to irradiate a homogenous and effective dose to the thyroid region. Recent advances in RT techniques such as intensity-modulated radiotherapy (IMRT) provided the potential to conquer the limitation. Additionally, IMRT using simultaneous integrated boost technique (SIB-IMRT) further improved the biologic and dosimetric advantages. As no previous literature has reported the use of this technique on locally advanced ATC, we report a 60-year-old female with ATC treated by debulky surgery and SIB-IMRT and review the literatures.