【摘要】 目的 調(diào)強(qiáng)放射治療（IMRT）能較好的保護(hù)危及器官并給予腫瘤足夠的致死劑量，基于多葉準(zhǔn)直器（MLC）分步照射的IMRT技術(shù)對復(fù)雜病例需要更多子野。研究對直腸癌術(shù)后放射治療使用不同子野數(shù)目的IMRT計劃進(jìn)行比對，選擇合理的子野數(shù)。 方法 選取2010年4-8月入院的直腸癌術(shù)后患者10例，保持射野入射角度及優(yōu)化目標(biāo)參數(shù)相同，僅改變MLC子野數(shù)目，設(shè)計不同IMRT對每一患者治療計劃的靶區(qū)適形指數(shù)（CI）、均勻性指數(shù)、最大劑量、最小劑量、平均劑量，危及器官關(guān)注體積的受照劑量，機(jī)器跳數(shù)及治療時間進(jìn)行分析。 結(jié)果 所有治療計劃中靶區(qū)及危及器官的劑量學(xué)評估指標(biāo)無統(tǒng)計學(xué)意義（P gt;0.05），只有亞臨床計劃靶區(qū)（PTV）CI在15個子野的方案中（0.74±0.06）明顯差于25個子野方案（0.82±0.03）、40個子野方案（0.81±0.06）及60個子野方案（0.84±0.03），有統(tǒng)計學(xué)意義（P lt;0.05）；治療機(jī)器跳數(shù)（MU）隨子野數(shù)目增多明顯增大，15、20、40及60個子野方案所需MU分別為（458±56）、（559±62）、（614±74）、（622±82），有統(tǒng)計學(xué)意義（P lt;0.05），但40個子野方案與60個子野方案間無統(tǒng)計學(xué)意義。治療時間明顯隨子野數(shù)增加而增大。 結(jié)論 直腸癌術(shù)后IMRT計劃使用25個子野能滿足臨床劑量要求，同時能有效降低治療時間，可作為臨床應(yīng)用參考值。
【Abstract】 Objective The intensity modulated radiotherapy (IMRT) can deliver tumor enough doses and protect risk organs as much as possible at the same time. The MLC-based step and shoot IMRT(sIMRT) plan needs much more segment member to meet clinical aims. In this study, several sIMRT plans using different segment number for postoperative rectal cancer were compared to find out the most reasonable segment number setting. Methods Ten patients with rectal carcinoma underwent postoperative adjuvant radiotherapy for rectal cancer from April to August 2010 were selected. For each patient, the angle of field, the prescription expected and the physical parameters optimized were kept the same, while only the number of segments was changed in sIMRT plans. The dose volume histogram-based parameters [conformity index (CI) and homogeneous index (HI)] and other parameters concerned were compared and analyzed. Results The indexes of dosimetry associated with the targets and risk organs showed no significant statistical difference among the 4 sIMRT plans with different segment numbers. The index CI of PTV in the sIMRT plan with 15 segments (CI 0.74±0.06) was less than that in the sIMRT plan with 25 segments (CI 0.82±0.03), the sIMRT plan with 40 segments plan (CI 0.81±0.06), and the sIMRT plan with 60 segments (CI 0.84±0.03) (P lt;0.05). There were significant differences in MU among the sIMRT plans with 15 segments (average MU: 458±56) , with 25 segments (average MU: 559±62 ), and with 40 segments (average MU: 614±74)or with the 60 segments (average MU: 622±82 (P lt;0.05). The more segments meant more MU and more irradiation time. Conclusion The sIMRT plan for patients of rectal cancer to receive postoperative adjuvant radiotherapy may require at least 25 segments to balance the accepted dose results and efficient delivering.
引用本文： 蔣曉芹,王武,沈亞麗,許峰,柏森. 子野數(shù)目對直腸癌術(shù)后調(diào)強(qiáng)放射治療計劃的影響. 華西醫(yī)學(xué), 2010, 25(12): 2138-2142. doi: 復(fù)制
| 1. | Greard JP, Chapet O, Nemoz C, et al. Improved sphincter preservation in low rectal cancer with high-dose preoperative radiotherapy: the lyon R96-02 randomized trial[J]. J Clin Oncol, 2004, 22(12): 2404-2409. |
| 2. | Glimelins B, Cronberg H, Jarhule J, et al. A systematic overview of radiation therapy effects in rectal cancer[J]. Aeta Oncol, 2003, 42(5-6): 477-492. |
| 3. | 姚波, 鄭明民, 王平, 等. 直腸癌五野調(diào)強(qiáng)放療與傳統(tǒng)適形放療劑量學(xué)研究[J]. 臨床腫瘤學(xué)雜志, 2005, 14(6): 483-486. |
| 4. | 錢立庭, 金大偉, 劉新, 等. 直腸癌術(shù)后輔助性放療不同照射技術(shù)的劑量學(xué)研究[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(1): 411-415. |
| 5. | 姚波, 鄭明民, 張艷, 等. 低位直腸術(shù)前調(diào)強(qiáng)同步加量并同步口服卡培他濱化療的初步研究[J]. 癌癥進(jìn)展雜志, 2009, 7(4): 442-447. |
| 6. | 胡逸民. 調(diào)強(qiáng)適形放射治療. 腫瘤放射物理學(xué)[M]. 北京: 原子能出版社，1999: 538-572. |
| 7. | Samuel Hellman. Treatment planning consideration in IMRT. A practical guide to intensity-modulated radiation therapy[M]. WI: Medical Physics publishing Madison, 2003: 103-122. |
| 8. | Luan S, Saia J, Young M. Approximation algorithm for minimizaing segments in radiation therapy[J]. Inf Proc Lett, 2007, 101(6): 239-244. |
| 9. | Engel K. A new algorithm for multileaf collimator field segmentation[J]. Discrete Applied Mathematics, 2005, 152(1-3): 35-51. |
| 10. | 伍志紅, 張九堂, 曾彪, 等. 鼻咽癌三種子野方案對調(diào)強(qiáng)放療劑量分布的影響[J]. 醫(yī)學(xué)臨床研究, 2009, 26(2): 241-244. |
| 11. | 陳真云, 馬悅冰, 盛修貴, 等. 32例婦科惡性腫瘤術(shù)后調(diào)強(qiáng)適形放射治療分析[J]. 中華腫瘤雜志, 2007, 29(4): 3058-308. |
| 12. | 房輝, 李曄雄, 余子豪, 等. 前列腺癌三維適形和調(diào)強(qiáng)放療的初步結(jié)果[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(3): 197-200. |
| 13. | 袁智勇, 高黎, 徐國鎮(zhèn), 等. 初治鼻咽癌調(diào)強(qiáng)放療的初步結(jié)果[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(4): 237-243. |
| 14. | 蔡勇, 何玉香, 韓樹奎, 等. 直腸癌盆腔常規(guī)放療與三維適形放療的劑量學(xué)研究[J]. 中華放射腫瘤學(xué)雜志, 2007, 16(3): 201-205. |
| 15. | Urbano MTG, Henrys AJ, Adams EJ, et al. Intensity-Modulated radiotherapy in patients with locally advanced rectal cancer reduces volume of bowel treated to high dose levels[J]. Int J Radiat Oncol Biol Phys, 2006, 65(3): 907-916. |
| 16. | 耿輝, 戴建榮, 李曄雄, 等. 一種簡單調(diào)強(qiáng)放療技術(shù)應(yīng)用的初步研究[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(1): 411-415. |
- 1. Greard JP, Chapet O, Nemoz C, et al. Improved sphincter preservation in low rectal cancer with high-dose preoperative radiotherapy: the lyon R96-02 randomized trial[J]. J Clin Oncol, 2004, 22(12): 2404-2409.
- 2. Glimelins B, Cronberg H, Jarhule J, et al. A systematic overview of radiation therapy effects in rectal cancer[J]. Aeta Oncol, 2003, 42(5-6): 477-492.
- 3. 姚波, 鄭明民, 王平, 等. 直腸癌五野調(diào)強(qiáng)放療與傳統(tǒng)適形放療劑量學(xué)研究[J]. 臨床腫瘤學(xué)雜志, 2005, 14(6): 483-486.
- 4. 錢立庭, 金大偉, 劉新, 等. 直腸癌術(shù)后輔助性放療不同照射技術(shù)的劑量學(xué)研究[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(1): 411-415.
- 5. 姚波, 鄭明民, 張艷, 等. 低位直腸術(shù)前調(diào)強(qiáng)同步加量并同步口服卡培他濱化療的初步研究[J]. 癌癥進(jìn)展雜志, 2009, 7(4): 442-447.
- 6. 胡逸民. 調(diào)強(qiáng)適形放射治療. 腫瘤放射物理學(xué)[M]. 北京: 原子能出版社，1999: 538-572.
- 7. Samuel Hellman. Treatment planning consideration in IMRT. A practical guide to intensity-modulated radiation therapy[M]. WI: Medical Physics publishing Madison, 2003: 103-122.
- 8. Luan S, Saia J, Young M. Approximation algorithm for minimizaing segments in radiation therapy[J]. Inf Proc Lett, 2007, 101(6): 239-244.
- 9. Engel K. A new algorithm for multileaf collimator field segmentation[J]. Discrete Applied Mathematics, 2005, 152(1-3): 35-51.
- 10. 伍志紅, 張九堂, 曾彪, 等. 鼻咽癌三種子野方案對調(diào)強(qiáng)放療劑量分布的影響[J]. 醫(yī)學(xué)臨床研究, 2009, 26(2): 241-244.
- 11. 陳真云, 馬悅冰, 盛修貴, 等. 32例婦科惡性腫瘤術(shù)后調(diào)強(qiáng)適形放射治療分析[J]. 中華腫瘤雜志, 2007, 29(4): 3058-308.
- 12. 房輝, 李曄雄, 余子豪, 等. 前列腺癌三維適形和調(diào)強(qiáng)放療的初步結(jié)果[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(3): 197-200.
- 13. 袁智勇, 高黎, 徐國鎮(zhèn), 等. 初治鼻咽癌調(diào)強(qiáng)放療的初步結(jié)果[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(4): 237-243.
- 14. 蔡勇, 何玉香, 韓樹奎, 等. 直腸癌盆腔常規(guī)放療與三維適形放療的劑量學(xué)研究[J]. 中華放射腫瘤學(xué)雜志, 2007, 16(3): 201-205.
- 15. Urbano MTG, Henrys AJ, Adams EJ, et al. Intensity-Modulated radiotherapy in patients with locally advanced rectal cancer reduces volume of bowel treated to high dose levels[J]. Int J Radiat Oncol Biol Phys, 2006, 65(3): 907-916.
- 16. 耿輝, 戴建榮, 李曄雄, 等. 一種簡單調(diào)強(qiáng)放療技術(shù)應(yīng)用的初步研究[J]. 中華放射腫瘤學(xué)雜志, 2006, 15(1): 411-415.