A radiotherapy plan following breast-conserving surgery for improving the dose distribution at
the junction region between supra-clavicular fossa region and breast region(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2020年第9期
- Page:
- 1095-1100
- Research Field:
- 医学人工智能
- Publishing date:
Info
- Title:
- A radiotherapy plan following breast-conserving surgery for improving the dose distribution at
the junction region between supra-clavicular fossa region and breast region
- Author(s):
- BI Suyan; REN Hua; WANG Yuenan
- National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital，Chinese Academy of
Medical Sciences and Peking Union Medical College, Shenzhen 518116, China
- Keywords:
- breast cancer intensity-modulated radiotherapy breast region supra-clavicular fossa region dosimetry
- PACS:
- R811.1
- DOI:
- 10.3969/j.issn.1005-202X.2020.09.003
- Abstract:
- Objective To introduce a modified radiotherapy plan after breast-conserving surgery for improving the uniformity of
dose distribution at the junction region between supra-clavicular fossa (SC) region and breast region. Methods Ten patients who
underwent treatment and required both SC irradiation and breast irradiation were selected for the study. Conventional plan included
3-field intensity-modulated radiotherapy (IMRT) on SC region and hybrid IMRT on breast region. The plans of 10 patients were
re-planned using the proposed method.With 3-field IMRT on SC region, field-in-field technique was applied on tangential breast
fields for creating a dose gradient at the junction region by adjusting the position of mutli-leaf collimator leaves. The dosimetric
differences between two plans were compared. The dosimetric indicators of target areas included the Dmax, Dmin, conformity index
(CI) and homogeneity index (HI) of PTV and PTV_J. PTV_J was defined as the volume of the junction region, which was 1 cm
cranial and 1 cm caudal to the iso-center in PTV. The dosimetric indicators of organs-at-risk included the V5, V20, V30, Dmean of the
affected lung, the Dmean of the heart, the V20, Dmean of the contralateral breast and the Dmax of spinal cord. Results The CI and HI
of PTV_J in modified plan were superior to those in conventional plan (P<0.05). However, there was no significant difference
in the CI and HI of PTV and the dosimetric indicators of organs-at-risk (all P>0.05). Conclusion The modified plan which can
improve the dose distribution at the junction region, without affecting the doses of target areas and organs-at-risk, can be applied
into the radiotherapy for breast cancer.
Last Update: 2020-09-25