Wang Juanqi, Yang Zhaozhi, Hu Weigang, Chen Zhi, Yu Xiaoli, Guo Xiaomao
Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, 200032, Shanghai, China.
Oncotarget. 2017 May 16;8(20):33276-33284. doi: 10.18632/oncotarget.16634.
The purpose of this study is to evaluate the intensity modulated radiotherapy (IMRT) with the fixed collimator jaws technique (FJT) for the left breast and regional lymph node. The targeted breast tissue and the lymph nodes, and the normal tissues were contoured for 16 left-sided breast cancer patients previously treated with radiotherapy after lumpectomy. For each patient, treatment plans using different planning techniques, i.e., volumetric modulated arc therapy (VMAT), tangential IMRT (tangential-IMRT), and IMRT with FJT (FJT-IMRT) were developed for dosimetric comparisons. A dose of 50Gy was prescribed to the planning target volume. The dose-volume histograms were generated, and the paired t-test was used to analyze the dose differences. FJT-IMRT had similar mean heart volume receiving 30Gy (V30 Gy) with tangential-IMRT (1.5% and 1.6%, p = 0.41), but inferior to the VMAT (0.8%, p < 0.001). In the average heart mean dose comparison, FJT-IMRT had the lowest value, and it was 0.6Gy lower than that for the VMAT plans (p < 0.01). A significant dose increase in the contralateral breast and lung was observed in VMAT plans. Compared with tangential-IMRT and VMAT plans, FJT-IMRT reduced the mean dose of thyroid, humeral head and cervical esophageal by 47.6% (p < 0.01) and 45.7% (p < 0.01), 74.3% (p =< 0.01) and 73% (p =< 0.01), and 26.7% (p =< 0.01) and 29.2% (p =< 0.01). In conclusion, compared with tangential-IMRT and VMAT, FJT-IMRT plan has the lowest thyroid, humeral head and cervical esophageal mean dose and it can be a reasonable treatment option for a certain subgroup of patients, such as young left-breast cancer patients and/or patients with previous thyroid disease.
本研究的目的是评估采用固定准直器钳口技术（FJT）对左侧乳腺及区域淋巴结进行调强放疗（IMRT）的效果。对16例左侧乳腺癌患者在保乳术后接受放疗的靶区乳腺组织、淋巴结及正常组织进行轮廓勾画。针对每位患者，制定了使用不同计划技术的治疗计划，即容积调强弧形放疗（VMAT）、切线IMRT（tangential-IMRT）和FJT-IMRT，以进行剂量学比较。处方剂量为50Gy至计划靶体积。生成剂量体积直方图，并采用配对t检验分析剂量差异。FJT-IMRT接受30Gy的平均心脏体积（V30 Gy）与tangential-IMRT相似（分别为1.5%和1.6%，p = 0.41），但低于VMAT（0.8%，p < 0.001）。在平均心脏平均剂量比较中，FJT-IMRT的值最低，比VMAT计划低0.6Gy（p < 0.01）。在VMAT计划中观察到对侧乳腺和肺的剂量显著增加。与tangential-IMRT和VMAT计划相比，FJT-IMRT使甲状腺、肱骨头和颈段食管的平均剂量分别降低了47.6%（p < 0.01）和45.7%（p < 0.01）、74.3%（p <= 0.01）和73%（p <= 0.01）、26.7%（p <= 0.01）和29.2%（p <= 0.01）。总之，与tangential-IMRT和VMAT相比，FJT-IMRT计划的甲状腺、肱骨头和颈段食管平均剂量最低，对于某些亚组患者，如年轻的左侧乳腺癌患者和/或既往有甲状腺疾病的患者，它可能是一种合理的治疗选择。
