A Comparison of Lumpectomy Cavity Delineations Between Use of Magnetic Resonance Imaging and Computed Tomography Acquired With Patient in Prone Position for Radiation Therapy Planning of Breast Cancer. Int J Radiat Oncol Biol Phys 2016 Mar 15;94(4):832-40
Date
03/15/2016Pubmed ID
26972656DOI
10.1016/j.ijrobp.2015.12.014Scopus ID
2-s2.0-84959464641 (requires institutional sign-in at Scopus site) 12 CitationsAbstract
PURPOSE: To compare lumpectomy cavity (LC) and planning target volume (PTV) delineated with the use of magnetic resonance imaging (MRI) and computed tomography (CT) and to examine the possibility of replacing CT with MRI for radiation therapy (RT) planning for breast cancer.
METHODS AND MATERIALS: MRI and CT data were acquired for 15 patients with early-stage breast cancer undergoing lumpectomy during RT simulation in prone positions, the same as their RT treatment positions. The LCs were delineated manually on both CT (LC-CT) and MRI acquired with 4 sequences: T1, T2, STIR, and DCE. Various PTVs were created by expanding a 15-mm margin from the corresponding LCs and from the union of the LCs for the 4 MRI sequences (PTV-MRI). Differences were measured in terms of cavity visualization score (CVS) and dice coefficient (DC).
RESULTS: The mean CVSs for T1, T2, STIR, DCE, and CT defined LCs were 3.47, 3.47, 3.87, 3.50. and 2.60, respectively, implying that the LC is mostly visible with a STIR sequence. The mean reductions of LCs from those for CT were 22%, 43%, 36%, and 17% for T1, T2, STIR, and DCE, respectively. In 14 of 15 cases, MRI (union of T1, T2, STIR, and DCE) defined LC included extra regions that would not be visible from CT. The DCs between CT and MRI (union of T1, T2, STIR, and DCE) defined volumes were 0.65 ± 0.20 for LCs and 0.85 ± 0.06 for PTVs. There was no obvious difference between the volumes of PTV-MRI and PTV-CT, and the average PTV-STIR/PTV-CT volume ratio was 0.83 ± 0.23.
CONCLUSIONS: The use of MRI improves the visibility of LC in comparison with CT. The volumes of LC and PTV generated based on a MRI sequence are substantially smaller than those based on CT, and the PTV-MRI volumes, defined by the union of T1, T2, STIR, and DCE, were comparable with those of PTV-CT for most of the cases studied.
Author List
Huang W, Currey A, Chen X, Li B, Bergom C, Kelly T, Wilson JF, Li XAAuthors
Xiaojian Chen PhD Assistant Professor in the Radiation Oncology department at Medical College of WisconsinAdam Currey MD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
Tracy R. Kelly MD Associate Professor in the Radiation Oncology department at Medical College of Wisconsin
J Frank Wilson MD Professor Emeritus in the Radiation Oncology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AdultAged
Aged, 80 and over
Breast Neoplasms
Female
Humans
Magnetic Resonance Imaging
Mastectomy, Segmental
Middle Aged
Patient Positioning
Prone Position
Radiotherapy Planning, Computer-Assisted
Tomography, X-Ray Computed
Tumor Burden
