目的：分析以螺旋刀放射治療儀低分次放射治療（HT，Hypofractionated Tomotherapy）第4期非小細胞肺癌（NSCLC, non-small cell lung cancer）肺內病灶之臨床經驗。
材料與方法：自2007年4月至2011年7月，共計有27位第4期NSCLC患者接受HT治療其肺內病灶。所有患者肺內病灶數目不大於5個，且任一病灶不大於5cm，主要分析為整體生存期、照野內復發以及放射性肺炎之發生。患者治療計畫需參考高能電腦斷層之影像（MVCT,megavoltage computerized tomography）。患者接受放射分次數介於9至16次，中位數為10次，單次劑量平均數為4.7±0.3 Gy（平均數±標準差），總劑量平均數為48.6±6.8 Gy 。
結果：全部病人追蹤時間中位數（median follow up）為16.1月，追蹤期內無照野內復發。整體生存期中位數（median overall survival）為32.1月。患有肺外轉移病灶（EPD, extrapulmonarydisease）之患者，其整體生存期中位數為11.2月，無EPD之患者，其整體生存期中位數則為38.6月，兩者之間具有顯著差異（p值等於 0.003），以肺內病灶數量作觀察，轉移病灶數量小於3 者，其整體生存期中位數為34.7月，轉移病灶數量介於3至5者，其整體生存期中位數則為32.1 月，兩者之間無顯著差異（p值等於0.57）。肺內病灶總體積平均數為39.18±39.98 ㎤。肺平均劑量為7.34±3.38 Gy。以肺內病灶總體積做評估，轉移病灶總體積小於或等於27.89 ㎤者，其整體生存期中位數為34.7月，轉移病灶總體積大於27.89 ㎤者，其整體生存期中位數則為12.3 月，兩者之間具有具顯著差異（p值等於0.04）。共2位發生第3級以上之放射性肺炎。
結論：使用HT治療小於或等於5個第4期非小細胞肺癌肺內病灶，可得到良好之腫瘤局部控制率。有無肺外轉移病灶以及肺內病灶總體積皆為影響整體生存期之重要預後因子。

Introduction : To retrospectively evaluate Hypofractionated Tomotherapy (HT) on the treatment ofintrathoracic lesions in patients with stage IV non-small cell lung cancer (NSCLC).Material and Methods : Between April 2007 and July 2011, 27 stage IV NSCLC patients weretreated with HT for their intrathoracic lesions. The number of intrathocic lesions was ≦ 5 and noneof them exceeded 5 cm in greatest dimension. Overall survival, rate of in-field recurrence andincidence of radiation pneumonitis were analyzed. Megavoltage computerized tomography (MVCT)was utilized for tumor contouring. The mean radiation dose per fraction was 4.7 ± 0.3 Gy (mean ±standard deviation) and the number of fractions ranged between 9 and 16 (median: 10 fractions). Totalirradiation dose was 48.8±6.8 Gy.
Results : The median follow-up period was 16.1 months. There was no in-field failure. The medianduration of overall survival was 11.2 months among patients with extrapulmonary disease (EPD)and 38.6 months among patients without EPD (p = 0.03). The median duration of overall survivalwas 34.7 months among patients with < 3 intrathoracic GTVs and 32.1 months among patientswith 3-5 intrathoracic GTVs (p = 0.57). The aggregated intrathoracic GTV in each patient averaged39.18±39.98 ㎤. The median duration of overall survival was 38.6 months among patients withaggregated intrathoracic GTV ≦ 27.89 ㎤ and 12.3 months among patients with aggregatedintrathothoracic GTV > 27.89 ㎤ (p= 0.04). Two patients developed grade 3 or greater radiationpneumonitis.
Conclusion : HT may be feasible for selected stage IV NSCLC patients with the number ofintrathoracic lesions less than or equal to 5. Excellent local control can be anticipated. Presence of EPDand volume of intrathoracic lesions may be significant prognostic factors for overall survival.