目的：探討舌根癌病人的腫瘤體積對於強度調控放射治療預後的影響。材料與方法：回溯性分析從2003 年到2009 年期間，35 位確診為臨床二至四期鱗狀上皮癌舌根癌且接受器官保留治療病人的病例紀錄。所有病人皆完成兩階段強度調控式放射線治療，每天接受之放射劑量為1.8 Gy ，原發腫瘤與轉移性淋巴結接受的總劑量之中位值為70.2 Gy ，預防性頸部淋巴的劑量之中位值為50.4 Gy 。其中的24 位病人接受合併cisplatin 之同步化學治療（cisplatin 80-100 mg/m2，放療開始的第 1 、22 、43 天）。原發腫瘤體積之測量與計算分別取自放射治療前及治療期中之模擬攝影影像。結果：經過中位值18 個月的追蹤時間，24 位病人（68.5%）被發現有原發腫瘤或頸部淋巴之局部復發。所有病人之兩年癌症相關存活率為24% ，其中第二至三期病人的癌症相關存活率為25% ，第四期病人之癌症相關存活率為9%（p= 0.13）。另 T2-T3 腫瘤的兩年原發腫瘤無復發率為 35% ，而 T4 腫瘤的則降至0%（p= 0.01）。原發腫瘤體積之中位值為34.6 mL（範圍，8.0 至165 mL），而治療中之原發腫瘤體積之中位值為9.4-19.4 mL（範圍，3.8 至79.3 mL）。多變數分析發現原發腫瘤復發之不良預後因子為原發腫瘤體積大於 20 mL（p= 0.005，勝算比5.87，95% 信賴區間 1.29-26.7）與放療期中腫瘤體積降低比率小於 0.4（p= 0.002，勝算比3.74，95%信賴區間 1.68~9.73）。結論：本研究報告顯示強度調控治療對於施行器官保留術之舌根癌病人的治療成效並不理想，對於原發腫瘤體積大於20 mL 或放療期中腫瘤體積降低比率小於0.4 的病人，必須考慮以更積極的治療方式來提高局部腫瘤的控制率，如提高局部放射治療劑量或是合併治療。

Purpose : To investigate the impact of tumor volume in patients with the base of tongue (BOT) cancer treated with definitive intensity-modulated radiotherapy technique (IMRT).Materials and Methods : From 2003 to 2009, 35 patients with stage II-IV squamous cell carcinoma of the BOT cancer receiving organ preservation scheme were enrolled in this retrospective analysis. Radiotherapy was performed using a sequential IMRT.All patients received 1.8 Gy daily up to a median total dose of 70.2 Gy to gross tumors
and metastatic lymph nodes, whereas the area harboring microscopic disease was prescribed with a median dose of 50.4 Gy. Twenty-four patients had concurrent chemotherapy.The regimen consisted of cisplatin (80–100 mg/m2 on Days 1, 22, 43). Primary tumor volume measurement was derived using separate simulation images for the pretreatment gross tumor volume (pGTV) and the interval gross tumor volume (iGTV).Results : With a median follow-up duration of 18 months, 24 patients (68.5%) were
found to have locoregional failures. The 2-year cause-specific survival was for all patients was 24%. The curve could be split into 25% for stage II-III disease, and 18% for stage IV disease (p= 0.29). The 2-year primary relapse-free survival (PRFS)was 35 % for patients with T2-T3 disease, and the curve dropped to zero for patients with T4 disease (p= 0.01). The pGTV value ranged from 8.1 to 165 mL (median, 34.6mL), whereas the iGTV ranged from 3.8 to 79.3 mL (median, 19.4 mL). Multivariate
analysis showed that there were two predictors for the PRFS: pGTV  20ml (p= 0.02,hazard ratio= 5.87, 95% CI 1.29-26.72) and volume reduction rate (VRR) < 0.4 (p =0.002, hazard ratio 4.33, 95% CI 1.71~10.99).
Conclusions : This preliminary study shows that IMRT outcome in the BOT cancer patients was unsatisfactory. To optimize the treatment result, an aggressive treatment scheme should be considered for large pretreatment tumor burden or a VRR less than 0.4.