title: Dosimetric Evaluation of Different Intensity-Modulated Radiotherapy Techniques for Breast Cancer After Conservative Surgery.
abstract: Intensity-modulated radiotherapy (IMRT) potentially leads to a more favorite dose distribution compared to 3-dimensional or conventional tangential radiotherapy (RT) for breast cancer after conservative surgery or mastectomy. The aim of this study was to compare dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) among helical tomotherapy (HT), inverse-planned IMRT (IP-IMRT), and forward-planned field in field (FP-FIF) IMRT techniques after breast-conserving surgery. Computed tomography scans from 20 patients (12 left sided and 8 right sided) previously treated with T1N0 carcinoma were selected for this dosimetric planning study. We designed HT, IP-IMRT, and FP-FIF plans for each patient. Plans were compared according to dose-volume histogram analysis in terms of PTV homogeneity and conformity indices (HI and CI) as well as OARs dose and volume parameters. Both HI and CI of the PTV showed statistically significant difference among IP-IMRT, FP-FIF, and HT with those of HT were best (P < .05). Compared to FP-FIF, IP-IMRT showed smaller exposed volumes of ipsilateral lung, heart, contralateral lung, and breast, while HT indicated smaller exposed volumes of ipsilateral lung but larger exposed volumes of contralateral lung and breast as well as heart. In addition, HT demonstrated an increase in exposed volume of ipsilateral lung (except for fraction of lung volume receiving >30 Gy and 20 Gy), heart, contralateral lung, and breast compared with IP-IMRT. For breast cancer radiotherapy (RT) after conservative surgery, HT provides better dose homogeneity and conformity of PTV compared to IP-IMRT and FP-FIF techniques, especially for patients with supraclavicular lymph nodes involved. Meanwhile, HT decreases the OAR volumes receiving higher doses with an increase in the volumes receiving low doses, which is known to lead to an increased rate of radiation-induced secondary malignancies. Hence, composite factors including dosimetric advantage, clinical effect, and economic burden should be taken into comprehensive consideration when choosing an RT technique in clinical practice.
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Fuli
authors.initials: F
authors.lastname: Zhang
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China wangyadi@hotmail.com.
authors.forename: Yadi
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Xu
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Huayong
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Qingzhi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Junmao
authors.initials: J
authors.lastname: Gao
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Bo
authors.initials: B
authors.lastname: Yao
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Jun
authors.initials: J
authors.lastname: Hou
authors.affiliation: Radiation Oncology Department, The Military General Hospital of Beijing PLA, Beijing, P.R. China.
authors.forename: Heliang
authors.initials: H
authors.lastname: He
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery*; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods*; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods; D058958:Organs at Risk / Q000528:radiation effects; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D014057:Tomography, X-Ray Computed
keywords: breast cancer; forward-planned intensity-modulated radiation therapy; helical tomotherapy; inverse-planned intensity-modulated radiation therapy