PMID- 34285583 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20220428 IS - 1179-1322 (Print) IS - 1179-1322 (Electronic) IS - 1179-1322 (Linking) VI - 13 DP - 2021 TI - The Impact of Different Simulation Modalities on Target Volume Delineation in Breast-Conserving Radiotherapy. PG - 5633-5640 LID - 10.2147/CMAR.S301705 [doi] AB - PURPOSE: In the management of breast-conserving radiotherapy, computed tomography (CT) simulation is now commonly used to identify tumor bed while has difficulties defining precisely. We aimed to evaluate the impact of magnetic resonance (MR) and CT simulation on defining the postoperative tumor bed for breast-conserving radiotherapy in patients without the aid of surgical clips. METHODS: From August 2018 to March 2019, twenty patients with T(1-2)N(0)M(0) breast cancer at our institution were enrolled. All the patients underwent breast-conserving surgery without implantation of surgical clips and were prepared to receive radiotherapy. CT and MR images were acquired on the same day for each patient. Three radiation oncologists independently assigned cavity visualization score (CVS) and delineated the tumor bed based on first the CT then the MR images. Interobserver variability was assessed by volumes, generalized conformity index (CI(gen)) and the distance between the centers of mass (dCOM). Differences in mean values for parameters were tested by paired t-test or one-way analysis of variance, as appropriate. RESULTS: First, the mean volumes of tumor bed derived from MR were 22%, 27% and 21% smaller than those based on CT images for each observer. In addition, the mean CI(gen) was significantly superior, and dCOM was smaller for MR than for CT images (CI(gen): 0.59 vs 0.52, P= 0.008; dCOM: 1.30 cm vs 1.39 cm, P= 0.095). Moreover, the mean CVS was 3.23+/-1.34 and 2.43+/-0.92 for MR and CT images, respectively (P= 0.035). Last, a positive association was observed between the CVS and CI(gen) for both modalities (P< 0.01). CONCLUSION: Compared to CT, MR can improve the visualization of changes in the postoperative tumor bed. In addition, MR can yield a more precise definition of the tumor bed and improve the consistency of tumor bed contouring in patients without surgical clips. CI - (c) 2021 Jin et al. FAU - Jin, Meng AU - Jin M AUID- ORCID: 0000-0002-6169-8110 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. AD - Department of Radiation Oncology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China. FAU - Liu, Xia AU - Liu X AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Ma, Jiabin AU - Ma J AUID- ORCID: 0000-0002-8912-2762 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Sun, Xiansong AU - Sun X AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Zhen, Hongnan AU - Zhen H AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Shen, Jing AU - Shen J AUID- ORCID: 0000-0002-4566-5925 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Liu, Zhikai AU - Liu Z AUID- ORCID: 0000-0001-5576-2318 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Lian, Xin AU - Lian X AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Miao, Zheng AU - Miao Z AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Hu, Ke AU - Hu K AUID- ORCID: 0000-0003-1079-5137 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Hou, Xiaorong AU - Hou X AUID- ORCID: 0000-0002-4903-9489 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. FAU - Zhang, Fuquan AU - Zhang F AUID- ORCID: 0000-0002-6856-2320 AD - Department of Radiation Oncology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. LA - eng PT - Journal Article DEP - 20210712 PL - New Zealand TA - Cancer Manag Res JT - Cancer management and research JID - 101512700 PMC - PMC8285125 OTO - NOTNLM OT - breast cancer OT - magnetic resonance simulation OT - radiotherapy OT - target volume delineation COIS- The authors declare that they have no conflicts of interests. EDAT- 2021/07/22 06:00 MHDA- 2021/07/22 06:01 PMCR- 2021/07/12 CRDT- 2021/07/21 06:31 PHST- 2021/01/18 00:00 [received] PHST- 2021/06/29 00:00 [accepted] PHST- 2021/07/21 06:31 [entrez] PHST- 2021/07/22 06:00 [pubmed] PHST- 2021/07/22 06:01 [medline] PHST- 2021/07/12 00:00 [pmc-release] AID - 301705 [pii] AID - 10.2147/CMAR.S301705 [doi] PST - epublish SO - Cancer Manag Res. 2021 Jul 12;13:5633-5640. doi: 10.2147/CMAR.S301705. eCollection 2021.