Modality-specific target definition for laryngeal and hypopharyngeal cancer on FDG-PET, CT and MRI

• Published in: Radiotherapy and oncology Vol. 123; no. 1; pp. 63 - 70
• Main Authors: Ligtenberg, Hans, Jager, Elise Anne, Caldas-Magalhaes, Joana, Schakel, Tim, Pameijer, Frank A, Kasperts, Nicolien, Willems, Stefan M, Terhaard, Chris H.J, Raaijmakers, Cornelis P.J, Philippens, Marielle E.P
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.04.2017
• Subjects: Aged; CTV; Female; Fluorodeoxyglucose F18; GTV; Head and neck cancer; Hematology, Oncology and Palliative Medicine; Humans; Hypopharyngeal Neoplasms - diagnostic imaging; Hypopharyngeal Neoplasms - pathology; Hypopharyngeal Neoplasms - surgery; Hypopharynx - diagnostic imaging; Hypopharynx - pathology; Hypopharynx - surgery; Imaging; Imaging, Three-Dimensional - methods; Laryngeal Neoplasms - diagnostic imaging; Laryngeal Neoplasms - pathology; Laryngeal Neoplasms - surgery; Laryngectomy; Larynx - diagnostic imaging; Larynx - pathology; Larynx - surgery; Magnetic Resonance Imaging - methods; Male; Middle Aged; Pathology; Positron-Emission Tomography - methods; Preoperative Care - methods; Radiopharmaceuticals; Tomography, X-Ray Computed - methods; GTV; Pathology; Head and neck cancer; CTV; Imaging
• ISSN: 0167-8140; 1879-0887
• DOI: 10.1016/j.radonc.2017.02.005

Abstract Background and purpose The goal of this study was to improve target definition by deriving modality-specific margins for clinical target volumes (CTV) for laryngeal and hypopharyngeal cancer on CT, MRI and 18-FDG-PET. Material and methods Twenty-five patients with T3/T4 laryngeal/hypopharyngeal cancer underwent CT, MRI and 18-FDG-PET scans before laryngectomy. HE-sections were obtained from the surgical specimen and tumor was delineated (tumorHE ). The GTVs on CT and MRI were delineated in consensus. PET-based GTVs were automatically segmented. The three-dimensionally reconstructed specimen was registered to the various images. Modality-specific CTV margins were derived and added to the GTVs to achieve adequate tumor coverage. The resulting CTVs were compared with each other, to tumorHE , and to CTVCT10 constructed on CT with the clinical margin of 10 mm. Results CTV margins of 4.3 mm (CT), 6.1 mm (MRI) and 5.2 mm (PET) were needed to achieve adequate tumor coverage. The median volumes of the resulting modality-specific CTVs were 44 ml (CT), 48 ml (MRI) and 39 ml (PET), while the CTV10mm was 80 ml. Conclusion For laryngohypopharyngeal tumors, 45–52% target volume reduction compared with CTV10mm is achievable when modality-specific CTV margins are used. PET-based CTVs were significantly smaller compared to CT- and MRI-based CTVs.