Gonzalez Victor J, Buchholz Daniel J, Langen Katja M, Olivera Gustavo H, Chauhan Bhavin, Meeks Sanford L, Ruchala Kenneth J, Haimerl Jason, Lu Weiguo, Kupelian Patrick A
Florida State University College of Medicine, Tallahassee, FL, USA.
Int J Radiat Oncol Biol Phys. 2006 May 1;65(1):284-90. doi: 10.1016/j.ijrobp.2005.12.044.
To evaluate two different techniques for whole-breast treatments delivered using the Hi-ART II tomotherapy device.
Tomotherapy uses the standard rotational helical delivery. Topotherapy uses a stationary gantry while delivering intensity-modulated treatments. CT scans from 5 breast cancer patients were used. The prescription dose was 50.4 Gy.
On average, 99% of the target volume received 95% of prescribed dose with either technique. If treatment times are restricted to less than 9 min, the average percentage ipsilateral lung receiving > or =20 Gy was 22% for tomotherapy vs. 10% for topotherapy. The ipsilateral lung receiving > or =50.4 Gy was 4 cc for tomotherapy vs. 27 cc for topotherapy. The percentage of left ventricle receiving > or =30 Gy was 14% with tomotherapy vs. 4% for topotherapy. The average doses to the contralateral breast and lung were 0.6 and 0.8 Gy, respectively, for tomotherapy vs. 0.4 and 0.3 Gy for topotherapy.
Tomotherapy provides improved target dose homogeneity and conformality over topotherapy. If delivery times are restricted, topotherapy reduces the amount of heart and ipsilateral lung volumes receiving low doses. For whole-breast treatments, topotherapy is an efficient technique that achieves adequate target uniformity while maintaining low doses to sensitive structures.
评估使用Hi-ART II断层放射治疗设备进行全乳治疗的两种不同技术。
断层放射治疗采用标准的旋转螺旋式照射。局部断层放射治疗在固定机架的同时进行调强治疗。使用了5例乳腺癌患者的CT扫描数据。处方剂量为50.4 Gy。
平均而言，两种技术中99%的靶体积接受了95%的处方剂量。如果将治疗时间限制在9分钟以内，断层放射治疗时同侧肺接受≥20 Gy的平均百分比为22%，而局部断层放射治疗为10%。断层放射治疗时同侧肺接受≥50.4 Gy的体积为4 cc，局部断层放射治疗为27 cc。断层放射治疗时左心室接受≥30 Gy的百分比为14%，局部断层放射治疗为4%。断层放射治疗时对侧乳腺和肺的平均剂量分别为0.6 Gy和0.8 Gy，局部断层放射治疗分别为0.4 Gy和0.3 Gy。
与局部断层放射治疗相比，断层放射治疗可提供更好的靶区剂量均匀性和适形性。如果限制照射时间，局部断层放射治疗可减少心脏和同侧肺接受低剂量的体积。对于全乳治疗，局部断层放射治疗是一种有效的技术，可在保持对敏感结构低剂量的同时实现足够的靶区均匀性。
