@article{4e267edc48a64a81aa6b5cd5a4584f46,
title = "Dosimetric Uncertainties Resulting From Interfractional Anatomic Variations for Patients Receiving Pancreas Stereotactic Body Radiation Therapy and Cone Beam Computed Tomography Image Guidance",
abstract = "Purpose: To estimate the effects of interfractional anatomic changes on dose to organs at risk (OARs) and tumors, as measured with cone beam computed tomography (CBCT) image guidance for pancreatic stereotactic body radiation therapy. Methods and Materials: We evaluated 11 patients with pancreatic cancer whom were treated with stereotactic body radiation therapy (33-40 Gy in 5 fractions) using daily CT-on-rails (CTOR) image guidance immediately before treatment with breath-hold motion management. CBCT alignment was simulated in the treatment planning software by aligning the original planning CT to each fractional CTOR image set via fiducial markers. CTOR data sets were used to calculate fractional doses after alignment by applying the rigid shift of the planning CT and CTOR image sets to the planning treatment isocenter and recalculating the fractional dose. Accumulated dose to the gross tumor volume (GTV), tumor vessel interface, duodenum, small bowel, and stomach were calculated by summing the 5 fractional absolute dose-volume histograms into a single dose-volume histogram for comparison with the original planned dose. Results: Four patients had a GTV D100% of at least 1.5 Gy less than the fractional planned value in several fractions; 4 patients had fractional underestimation of duodenum dose by 1.0 Gy per fraction. The D1.0 cm3 <35 Gy constraint was violated for at least 1 OAR in 3 patients, with either the duodenum (n = 2) or small bowel (n = 1) D1.0 cm3 being higher on the accumulated dose distribution (P =.01). D100% was significantly lower according to accumulated dose GTV (P =.01) and tumor vessel interface (P =.02), with 4 and 2 patients having accumulated D100% ≥4 Gy lower than the planned value for the GTV and tumor vessel interface, respectively. Conclusions: For some patients, CBCT image guidance based on fiducial alignment may cause large dosimetric uncertainties for OARs and target structures, according to accumulated dose.",
author = "Niedzielski, {Joshua S.} and Yufei Liu and Ng, {Sylvia S.W.} and Martin, {Rachael M.} and Perles, {Luis A.} and Sam Beddar and Neal Rebueno and Koay, {Eugene J.} and Cullen Taniguchi and Holliday, {Emma B.} and Prajnan Das and Smith, {Grace L.} and Minsky, {Bruce D.} and Ludmir, {Ethan B.} and Herman, {Joseph M.} and Albert Koong and Sawakuchi, {Gabriel O.}",
note = "Funding Information: This study has been supported by a Cancer Center Support (Core) Grant P30 CA016672 from the National Cancer Institute, National Institutes of Health, to University of Texas MD Anderson Cancer Center. Disclosures: G.O.S. reports having a research contract with Alpha Tau Medical. P.D. reports honorarium from Adlai Nortye, the American Society for Radiation Oncology, and Leidos Biomedical Research (National Cancer Institute). E.B.H. reports support from Merck & Co. E.J.K. reports grants from Philips Healthcare, Elekta, the National Institutes of Health, Stand Up To Cancer, and General Electric, as well as personal fees from Taylor & Francis and from RenovoRx. AK reports stock in Aravive, Inc. GLS reports grants from the National Cancer Institute, UT?MD Anderson Cancer Center, and the Andrew Sabin Family Foundation. C.T. reports consulting fees from Xerient, Inc., and Accuray, Inc. All authors declare no conflicts of interest with the work reported here. Funding Information: Disclosures: G.O.S. reports having a research contract with Alpha Tau Medical. P.D. reports honorarium from Adlai Nortye, the American Society for Radiation Oncology, and Leidos Biomedical Research (National Cancer Institute). E.B.H. reports support from Merck & Co. E.J.K. reports grants from Philips Healthcare, Elekta, the National Institutes of Health, Stand Up To Cancer, and General Electric, as well as personal fees from Taylor & Francis and from RenovoRx. AK reports stock in Aravive, Inc. GLS reports grants from the National Cancer Institute, UT—MD Anderson Cancer Center, and the Andrew Sabin Family Foundation. C.T. reports consulting fees from Xerient, Inc., and Accuray, Inc. All authors declare no conflicts of interest with the work reported here. Funding Information: This study has been supported by a Cancer Center Support (Core) Grant P30 CA016672 from the National Cancer Institute, National Institutes of Health, to University of Texas MD Anderson Cancer Center. Publisher Copyright: {\textcopyright} 2021 Elsevier Inc.",
year = "2021",
month = dec,
day = "1",
doi = "10.1016/j.ijrobp.2021.08.002",
language = "English (US)",
volume = "111",
pages = "1298--1309",
journal = "International Journal of Radiation Oncology Biology Physics",
issn = "0360-3016",
publisher = "Elsevier Inc.",
number = "5",
}