Critical Structure Sparing in Stereotactic Ablative Radiotherapy for Central Lung Lesions: Helical Tomotherapy vs. Volumetric Modulated Arc Therapy

Authors

Alexander Chi, West Virginia University
Pan Ma, Peking Union Medical College and Chinese Academy of Medical Sciences
Guishan Fu, Peking Union Medical College and Chinese Academy of Medical Sciences
Gerry Hobbs, West Virginia University
James S. Welsh, Fermi National Accelerator Laboratory
Nam P. Nguyen, University of Arizona
Si Y. Jang, University of Arizona
Jinrong Dai, Peking Union Medical College and Chinese Academy of Medical Sciences
Jing Jin, Peking Union Medical College and Chinese Academy of Medical Sciences
Ritsuko Komaki, The University of Texas MD Anderson Cancer Center

Author ORCID Identifier

https://orcid.org/0000-0002-9763-5867

N/A

N/A

https://orcid.org/0000-0001-7859-4257

https://orcid.org/0000-0002-3255-6412

N/A

N/A

N/A

N/A

https://orcid.org/0000-0002-8238-7055

Document Type

Article

Publication Date

2013

College/Unit

School of Medicine

Department/Program/Center

Radiation Oncology

Abstract

Background

Helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) are both advanced techniques of delivering intensity-modulated radiotherapy (IMRT). Here, we conduct a study to compare HT and partial-arc VMAT in their ability to spare organs at risk (OARs) when stereotactic ablative radiotherapy (SABR) is delivered to treat centrally located early stage non-small-cell lung cancer or lung metastases.

Methods

12 patients with centrally located lung lesions were randomly chosen. HT, 2 & 8 arc (Smart Arc, Pinnacle v9.0) plans were generated to deliver 70 Gy in 10 fractions to the planning target volume (PTV). Target and OAR dose parameters were compared. Each technique’s ability to meet dose constraints was further investigated.

Results

HT and VMAT plans generated essentially equivalent PTV coverage and dose conformality indices, while a trend for improved dose homogeneity by increasing from 2 to 8 arcs was observed with VMAT. Increasing the number of arcs with VMAT also led to some improvement in OAR sparing. After normalizing to OAR dose constraints, HT was found to be superior to 2 or 8-arc VMAT for optimal OAR sparing (meeting all the dose constraints) (p = 0.0004). All dose constraints were met in HT plans. Increasing from 2 to 8 arcs could not help achieve optimal OAR sparing for 4 patients. 2/4 of them had 3 immediately adjacent structures.

Conclusion

HT appears to be superior to VMAT in OAR sparing mainly in cases which require conformal dose avoidance of multiple immediately adjacent OARs. For such cases, increasing the number of arcs in VMAT cannot significantly improve OAR sparing.

Digital Commons Citation

Chi, Alexander; Ma, Pan; Fu, Guishan; Hobbs, Gerry; Welsh, James S.; Nguyen, Nam P.; Jang, Si Y.; Dai, Jinrong; Jin, Jing; and Komaki, Ritsuko, "Critical Structure Sparing in Stereotactic Ablative Radiotherapy for Central Lung Lesions: Helical Tomotherapy vs. Volumetric Modulated Arc Therapy" (2013). Faculty & Staff Scholarship. 2610.
https://researchrepository.wvu.edu/faculty_publications/2610

Source Citation

Chi A, Ma P, Fu G, Hobbs G, Welsh JS, Nguyen NP, et al. (2013) Critical Structure Sparing in Stereotactic Ablative Radiotherapy for Central Lung Lesions: Helical Tomotherapy vs. Volumetric Modulated Arc Therapy. PLoS ONE 8(4): e59729. https://doi.org/10.1371/journal.pone.0059729

Comments

© 2013 Chi et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.