鼻咽癌肋膜轉移常因腫瘤形成圓柱狀與鄰近危險器官而造成治療困難。導航螺旋刀是一新式影像導航之強度調控放射治療儀器，能提供高順形度腫瘤治療與危險器官閃避之功能。故導航螺旋刀可用於困難治療之腫瘤。一位 38 歲鼻咽癌患者因肋膜轉移造成強烈神經疼痛症狀，經導航螺旋刀 36 Gy 治療後，腫瘤體積從 629 ml 降至 158 ml，有效降低神經疼痛症狀。疼痛指數由 10 降至 0，同時無肺部副作用產生。故若以緩和治療為目的，導航螺旋刀亦可對特殊形狀之腫瘤提供有效且安全之治療。

Nasopharyngeal carcinoma (NPC) with pleural circulative metastasis is difficult to treat due to the cylinder shape and close critical organs. Helical tomotherapy (HT)is a new type of CT-based rotational intensity modulated radiotherapy with highly conformal dose distributions and critical organs sparing. HT could be helpful in this kind of difficult situation.A 38-year-old male Asian nasopharyngeal carcinoma patient with pleural and liver metastasis was treated. Thirty-six Gy was delivered to bilateral pleural and mediastinum metastatic sites with HT. After HT treatment, pain was controlled by narcotics successfully. Pain scale decreased from 10 to 0. Tumor volume decreased from 629ml to 158 ml. HT reduced V20 by more than 50% for each lung and reduced the mean lung dose by 22.2% and 33.8% in the right lung and left lung when compared with the
IMRT technique, respectively.For palliative treatment, HT provides impressive ability for irregularly shaped metastatic sites and reduces painful sensation successfully.