%0 Journal Article
%T 18F-fluoro-L-thymidine Positron Emission Tomography for Mucosal Head and Neck Squamous Cell Carcinoma Treated with Definitive Chemoradiation: A Pilot Study of Nodal Assessment and Tracer Safety
%A Charles Lin
%A Aravind Ravi Kumar
%A Jacqui Keller
%A Peter O¡¯Rourke
%A David McFarlane
%A Raymond Gwynne
%A Lizbeth Kenny
%A Nicole Buddle
%A Jarad Martin
%A Brett Hughes
%A Paul Thomas
%J ISRN Molecular Imaging
%D 2013
%R 10.1155/2013/710305
%X We aim to assess the utility and safety of 18F-fluoro-L-thymidine- positron emission tomography (FLT-PET), in reference to 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET) in the assessment of nodal involvement for mucosal head and neck SCC (HNSCC). Methods. Ten patients with HNSCC receiving definitive chemoradiation (CRT) were enrolled. Baseline FLT-PET and FDG-PET were obtained. The total number of involved lymph nodes and ultimate nodal staging by the baseline FDG-PET and FLT-PET was compared. Receiver Operating Characteristics (ROC) analysis for the matched nodes was performed to identify an optimal maximal standardized uptake value (SUVmax) cutpoint. Results. The tracer uptake by the involved nodes on FDG-PET was higher than those judged to be involved by FLT-PET (mean SUVmax: 5.9 versus 3.4; ). More abnormal lymph nodes were detected by FLT-PET than FDG-PET (Odds ratio = 3.67; ). The optimal SUVmax cutpoint for FLT-PET to correspond with positive FDG-PET for the matched lymph nodes was 3.25 (range 3.1¨C3.4). Conclusions. It is unlikely that FLT-PET will be a more accurate staging investigation than FDG-PET. A SUVmax of 3.25 may be considered as a reference cut-off in determining if a cervical lymph node is involved for HNSCC. Validation in a surgical cohort with pathological correlation is warranted. 1. Introduction Positron emission tomography using 18F-2-fluoro-2-deoxy-D-glucose (FDG-PET), generally now performed in conjunction with Computed Tomography (FDG PET/CT), has become a valuable part of modern oncological practice for a wide range of roles in a variety of malignancies [1, 2]. In the setting of mucosal head and neck squamous cell carcinoma (HNSCC), FDG-PET/CT is superior to conventional CT scanning for the detection of cervical lymph node metastases [3¨C5]. Other radiotracers offer the potential to biologically target various aspects of tumour behaviour. F-18 fluorothymidine (FLT) is a novel PET radiotracer that images cellular proliferation [6]. FLT is a radiolabeled analogue of thymidine which is retained in proliferating tissues through the enzyme thymidine kinase 1 (TK1) that phosphorylates FLT to FLT-5 phosphate. This unique feature makes FLT a promising tracer with the potential to play a valuable role in oncology practice. In contrast to FDG, which is preferentially taken up by cells consuming glucose, FLT is predominantly taken up by cells that undergo increased cellular proliferation. The degree of proliferative activity can be quantified by the maximal standardized uptake value (SUVmax). The role of FLT-PET in tumour staging was
%U http://www.hindawi.com/journals/isrn.molecular.imaging/2013/710305/