探討一罕見腦幹部位不成熟畸胎瘤，術後經局部放射治療及立骷定位放射治療的效果。材料與方法：一21歲女性因吸入性肺炎入院，經檢查為腦幹腫瘤引起咽反射（gag ref1ex）功能缺失，導致食物吸入性肺炎的反衼發生。並兩次出現突發性呼吸衰竭、血壓下降之危象。因腫瘤位於腦幹生命中樞，腦部顯微手術僅能部份摘除。病理報告顯示為不成熟畸胎瘤（immature teratoma）。術後之化學治療因再度發生呼吸停止、血壓下降而半途中止。為維持生命中樞的正常運作，予以局部放射治療，共39.6 Gy至計劃標的物體積。之後並以立體定位放射治療，對局部腫瘤追加至總劑量54.6 Gy。放射治療完成後兩週開始每月一次的化學治療，至今四次。結果：在整個放射治療結束後，血清及腦脊液中的阿發-胎兒蛋白（alpha fetoprotein ,AFP)、貝他-人類絨毛膜性腺激素（β-HCG）均由放射治療前的不正常偏高回復正常值。咽反射的功能逐漸恢復，不需再藉鼻胃管進食，亦不再有嗆到（chocking）或吸入性肺炎的發生。生命中樞的運作自開始放射治療起即持續穩定，不再有呼吸中止、血壓改變之危象。結論：對腦幹部位之不成熟畸胎瘤，本文有限的經驗下顯示局部放射治療合併立體定位放射治療對腫瘤局部控制及迅速緩解致命症狀均有正面的效果。

　　　　　Purpose: To report a rare case of brainstem immature teratoma treated bypost-operative limited-field radiotherapy and stereotactic radiotherapy.Materials and Methods: A 21-year-old female presented with symptoms and signs ofrecurrent aspiration pneumonia that was caused by dysphagia. She had two episodesof acute respiratory arrest and hypotension while in the hospital. Computedtomography (CT) of the brain revealed a heterogenous mass at lower brain stem region.Microscopic surgery only could yielded a piece of tumor that disclosed the entityof immature teratoma. Adjuvant chemotherapy with the regimen of cisplatin,etoposide, and bleomycin was administered, but was interrupted due to sudden onsetof respiratory arrest. In order to maintain brainstem function, limited-fieldirradiation with 39.6 Gy to planning target volume followed by a boost dose to theprimary site by stereotactic radiotherapy were performed with a total dose of 54.6Gy. Two weeks after radiotherapy, the patient began receiving monthly adjuvantchemotherapy for 4 cycles up to the time of this report.Results: Previously elevated serum and cerebrospinal fluid (CSF) levels of bothalpha-fetoprotein and beta human-chorionic gonadotropin returned to a normal rangeafter irradiation. The swallowing reflex gradually improved and the patient did notdevelop aspiration pneumonia again even after the NG tube was removed. Brainstemfunction has remained stable following irradiation.Conclusion: Our limited experience suggests that limited field radiotherapy followedby a boost dose with stereotactic radiotherapy is very effective in treating brainstemimmature teratoma for both local tumor control and relief of life-threateningsymptoms.