Comparison of dosimetry between forward intensity-modulated radiotherapy using field-in-field and inverse intensity-modulated radiotherapy for left-sided breast cancer after breast-conserving surgery
10.3760/cma.j.issn.1006-9801.2018.08.008
- VernacularTitle: 左侧乳腺癌保乳术后野中野正向调强放疗与逆向调强放疗剂量学比较
- Author:
Xiurong QI
1
;
Shuping ZHANG
;
Ruining SONG
;
Xinyue LI
Author Information
1. Department of Radiation Oncology, Shanxi Provincial People's Hospital, Taiyuan 030012, China
- Publication Type:Journal Article
- Keywords:
Breast neoplasms;
Radiotherapy dosage;
Radiotherapy, intensity-modulated
- From:
Cancer Research and Clinic
2018;30(8):541-544
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the dosimetric differences in forward intensity-modulated radiotherapy using field-in-field (FIF-F-IMRT) and inverse intensity-modulated radiotherapy (I-IMRT) for the left-sided breast cancer.
Methods:A total of 18 patients with left-sided breast cancer undergoing breast-conserving surgery in Shanxi Provincial People's Hospital from January to July 2015 were enrolled. For each patient, two treatment plans were designed. The plans were compared by means of target dose distribution and dose for organ at risk.
Results:The two methods met the requirements of the prescribed doses. There were no differences for maximal dose (Dmax), mean dose (Dmean), and 100%, 105%, 110% prescription dose percent volume (V100, V105, V110) of the target (all P > 0.05). The percentage volume of heart receiving 5 Gy (V5), 20 Gy (V20), 30 Gy (V30), Dmean of heart of FIF-F-IMRT [(11±4)%, (7±4)%, (8±3)%, (15±3) Gy] were lower than those of I-IMRT [(42±8)%, (14±10)%, (14±4)%, (18±7) Gy] (t values were 29.457, 5.542, 5.064, 4.165, all P = 0.000). V5 of left-sided lung of FIF-F-IMRT [(26±6)%] was lower than that of I-IMRT [(47±12)%] (t = 6.708, P = 0.000), but there was no significant difference between the two groups in V20, V30, V40, Dmean of left-sided lung (all P≥0.05). V5 of right-sided lung and right-sided breast, Dmean of right-sided lung of FIF-F-IMRT [(7±4)%, (26±5)%, (60±19) Gy] were lower than those of I-IMRT [(31±9)%, (48±11)%, (489±67) Gy] (t values were 12.304, 6.708, 42.489, all P = 0.000). The number of the monitor units and spending time of FIF-F-IMRT were lower than those of I-IMRT (t values were 12.214 and 29.899, both P = 0.000).
Conclusion:FIF-F-IMRT has a good dose distribution in the target volume, and could reduce the dose for organ at risk, especially reduce the unnecessary low dose irradiation, and consume less planning time and equipment consumption.
