Title |
Target volume delineation of anal cancer based on magnetic resonance imaging or positron emission tomography
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Published in |
Radiation Oncology, September 2017
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DOI | 10.1186/s13014-017-0883-z |
Pubmed ID | |
Authors |
Espen Rusten, Bernt Louni Rekstad, Christine Undseth, Ghazwan Al-Haidari, Bettina Hanekamp, Eivor Hernes, Taran Paulsen Hellebust, Eirik Malinen, Marianne Grønlie Guren |
Abstract |
To compare target volume delineation of anal cancer using positron emission tomography (PET) and magnetic resonance imaging (MRI) with respect to inter-observer and inter-modality variability. Nineteen patients with anal cancer undergoing chemoradiotherapy were prospectively included. Planning computed tomography (CT) images were co-registered with 18F-fluorodexocyglucose (FDG) PET/CT images and T2 and diffusion weighted (DW) MR images. Three oncologists delineated the Gross Tumor Volume (GTV) according to national guidelines and the visible tumor tissue (GTVT). MRI and PET based delineations were evaluated by absolute volumes and Dice similarity coefficients. The median volume of the GTVs was 27 and 31 cm(3) for PET and MRI, respectively, while it was 6 and 11 cm(3) for GTVT. Both GTV and GTVT volumes were highly correlated between delineators (r = 0.90 and r = 0.96, respectively). The median Dice similarity coefficient was 0.75 when comparing the GTVs based on PET/CT (GTVPET) with the GTVs based on MRI and CT (GTVMRI). The median Dice coefficient was 0.56 when comparing the visible tumor volume evaluated by PET (GTVT_PET) with the same volume evaluated by MRI (GTVT_MRI). Margins of 1-2 mm in the axial plane and 7-8 mm in superoinferior direction were required for coverage of the individual observer's GTVs. The rather good agreement between PET- and MRI-based GTVs indicates that either modality may be used for standard target delineation of anal cancer. However, larger deviations were found for GTVT, which may impact future tumor boost strategies. |
X Demographics
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Cyprus | 1 | 100% |
Demographic breakdown
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Members of the public | 1 | 100% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
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Unknown | 23 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
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Student > Ph. D. Student | 5 | 22% |
Researcher | 4 | 17% |
Student > Bachelor | 4 | 17% |
Other | 2 | 9% |
Student > Doctoral Student | 2 | 9% |
Other | 3 | 13% |
Unknown | 3 | 13% |
Readers by discipline | Count | As % |
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Medicine and Dentistry | 10 | 43% |
Nursing and Health Professions | 5 | 22% |
Physics and Astronomy | 2 | 9% |
Computer Science | 1 | 4% |
Unknown | 5 | 22% |