Comparation study of incidental irradiation dose to the internal mammary chain during postmastectomy radiotherapy for patients treated with different irradiation techniques
10.3760/cma.j.issn.0253-3766.2018.05.004
- VernacularTitle: 乳腺癌改良根治术后不同放疗计划方式下内乳区非计划性受照剂量的比较研究
- Author:
Wei WANG
1
;
Yingtao MENG
1
;
Yuanfang SONG
1
;
Tao SUN
2
;
Min XU
1
;
Qian SHAO
1
;
Yingjie ZHANG
1
;
Jianbin LI
1
Author Information
1. Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Jinan 250117, China
2. Department of Medical Physics, Shandong Cancer Hospital Affiliated to Shandong University, Jinan 250117, China
- Publication Type:Clinical Trail
- Keywords:
Breast neoplasm;
Mastectomy;
Radiotherapy;
Three-dimensional conformal radiotherapy;
Field-in-field forward intensity-modulated radiotherapy;
Field-in-field inverse intensity-modulated radiotherapy;
Internal mammary;
Incidental irradiation dose
- From:
Chinese Journal of Oncology
2018;40(5):335-340
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To evaluated the unplanned coverage dose to the internal mammary chain (IMC) in patient treated with postmastectomy radiotherapy (PMRT).
Methods:One hundred and thirty eight patients with breast cancer receiving radiotherapy (RT) in our hospital were retrospectively analyzed. Patients were divided into three groups: three-dimensional conformal radiotherapy (3D-CRT) group, forward intensity-modulated radiotherapy (F-IMRT) group and inverse IMRT (I-IMRT) group. The IMC were contoured according to Radiation Therapy Oncology Group (RTOG) consensus, and were not include into the planning target volume (PTV). The incidental irradiation dose to IMC among the three groups and the first three intercostal spaces IMC (ICS-IMC 1-3) were all compared, and explored the relationship between the mean doses (Dmean) of IMC and the OARs (ipsilateral lung and heart).
Results:The dose delivered to IMC showed no difference in CRT, F-IMRT and I-IMRT(33.80 Gy, 29.65 Gy and 32.95 Gy). And 10.42%, 2.04%, and 9.76% patients achieved ≥45 Gy when treated with CRT, F-IMRT and I-IMRT. For the IMC dose in the first three intercostal spaces (ICS1-3), there was no difference to the three treatment plannings. The Dmean, V20, V30, V40 and V50 of the ICS-IMC2 and ICS-IMC3 were all obviously superior than ICS-IMC1 for all these three plannings. Moderate positive correlation was founded between Dmean for IMC and Dmean for heart for left breast cancer patients underwent CRT (r=0.338, P=0.01). Whereas for F-IMRT and I-IMRT groups, positive correlation were founded between Dmean for IMC and Dmean and V20 for ipsilateral lung for all patients (F-IMRT: r=0.366, P=0.010; r=0.318, P=0.026; I-IMRT: r=0.427, P=0.005; r=0.411, P=0.008).
Conclusions:In 3D-CRT, F-IMRT and I-IMRT planning methods, partial patients get IMC irradiated doses that could achieve therapeutic doses. Compared with 3D-CRT, F-IMRT and I-IMRT further reduced the dose of irradiated organs. However, there is no difference in the dose coverage of IMC for the three planned approaches when the IMC made an unplanned target.
