PMID- 32381103
OWN - NLM
STAT- MEDLINE
DCOM- 20210322
LR  - 20210322
IS  - 1748-717X (Electronic)
IS  - 1748-717X (Linking)
VI  - 15
IP  - 1
DP  - 2020 May 7
TI  - Impact of positioning errors in the dosimetry of VMAT left-sided post mastectomy 
      irradiation.
PG  - 103
LID - 10.1186/s13014-020-01556-w [doi]
LID - 103
AB  - BACKGROUND: Volumetric modulated arc therapy (VMAT) adopted in post-mastectomy 
      radiation therapy (PMRT) has the capacity to achieve highly conformal dose 
      distributions. The research aims to evaluate the impact of positioning errors in 
      the dosimetry of VMAT left-sided PMRT. METHODS: A total of 18 perturbations where 
      introduced in 11 VMAT treatment plans that shifted the isocenter from its 
      reference position of 3, 5, 10 mm in six directions. The thoracic wall and 
      supraclavicular clinical target volumes (CTVs), the heart and the left lung dose 
      volume histograms (DVHs) of 198 perturbed plans were calculated. The absolute 
      differences (∆) of the mean dose (Dm) and DVH endpoints Vx and Dy (percentage 
      volume receiving x Gy, and dose covering y% of the volume, respectively) were 
      used to compare the dosimetry of the reference vs perturbed plans. RESULTS: 
      Isocenter shifts in the anterior and lateral directions lead to maximum 
      disagreement between the CTVs dosimetry of perturbed vs reference plans. 
      Isocenter shifts of 10 mm shown a decrease of D95, D98 and Dm of 12.8, 18.0, and 
      2.9% respectively, for the CTVs. For 5 mm isocenter shifts, these differences 
      decreased to 3.2, 5.2, and 0.9%, respectively, and for 3 mm shifts to 1.0, 1.7, 
      and 0.6%, respectively. For the organs at risk (OARs), only isocenter shifts in 
      the right, posterior and inferior directions worsen the plan dosimetry, 
      nevertheless not negligible lung ∆ V20 of + 2.6%, and heart ∆ V25 of + 1.6% 
      persist for 3 mm shifts. CONCLUSIONS: Inaccuracy in isocenter positioning for 
      VMAT left-sided PMRT irradiation may impact the dosimetry of the CTVs and OARs to 
      a different extent, depending on the directions and magnitude of the 
      perturbation. The acquired information could be useful for planning strategies to 
      guarantee the accuracy of the treatment delivered.
FAU - Liao, Xiongfei
AU  - Liao X
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Wu, Fan
AU  - Wu F
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Wu, Junxiang
AU  - Wu J
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Peng, Qian
AU  - Peng Q
AUID- ORCID: 0000-0001-5537-0656
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China. pengqian0522@163.com.
FAU - Yao, Xinghong
AU  - Yao X
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Kang, Shengwei
AU  - Kang S
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Zhao, Yanqun
AU  - Zhao Y
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
FAU - Orlandini, Lucia Clara
AU  - Orlandini LC
AD  - Sichuan Cancer Hospital & Research Institute, School of Medicine University of 
      Electronic Science and Technology of China, 55th Renmin South Road, 4th Section, 
      Chengdu, 610041, China.
LA  - eng
PT  - Journal Article
DEP - 20200507
PL  - England
TA  - Radiat Oncol
JT  - Radiation oncology (London, England)
JID - 101265111
SB  - IM
MH  - Female
MH  - Humans
MH  - Mastectomy
MH  - Patient Positioning/*adverse effects
MH  - Radiometry/methods
MH  - Radiotherapy Planning, Computer-Assisted/methods
MH  - Radiotherapy, Adjuvant/*methods
MH  - Radiotherapy, Intensity-Modulated/*methods
MH  - Retrospective Studies
MH  - Unilateral Breast Neoplasms/*radiotherapy/surgery
PMC - PMC7206823
OTO - NOTNLM
OT  - Breast cancer
OT  - Heart dose
OT  - Positioning errors
OT  - Radiotherapy
OT  - Volumetric modulated arc therapy
COIS- None of the authors have any competing interests (financial and non-financial) in 
      the manuscript.
EDAT- 2020/05/10 06:00
MHDA- 2021/03/23 06:00
PMCR- 2020/05/07
CRDT- 2020/05/09 06:00
PHST- 2020/01/14 00:00 [received]
PHST- 2020/04/28 00:00 [accepted]
PHST- 2020/05/09 06:00 [entrez]
PHST- 2020/05/10 06:00 [pubmed]
PHST- 2021/03/23 06:00 [medline]
PHST- 2020/05/07 00:00 [pmc-release]
AID - 10.1186/s13014-020-01556-w [pii]
AID - 1556 [pii]
AID - 10.1186/s13014-020-01556-w [doi]
PST - epublish
SO  - Radiat Oncol. 2020 May 7;15(1):103. doi: 10.1186/s13014-020-01556-w.