[18F]FLT-PET and [18F]FDG-PET in the evaluation of radiotherapy for laryngeal cancer

Been, Lukas B.; Hoekstra, Harald J.; Suurmeijer, Albert J.H.; Jager, Pieter L.; van der Laan, Bernard F.A.M.; Elsinga, Philip H.

doi:10.1016/j.oraloncology.2009.07.008

« Previous Next »Oral Oncology
Volume 45, Issue 12 , Pages e211-e215, December 2009

[¹⁸F]FLT-PET and [¹⁸F]FDG-PET in the evaluation of radiotherapy for laryngeal cancer

Lukas B. Been
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Surgical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Address: Department of Surgical Oncology, University Medical Center Groningen, P.O. Box 30.001, 9700 RB Groningen, Groningen, The Netherlands. Tel.: +31 50 3616161; fax: +31 50 3614873.
Harald J. Hoekstra
- Department of Surgical Oncology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Corresponding author. Address: Department of Surgical Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9713 GZ Groningen, Groningen, The Netherlands. Tel.: +31 50 3612303; fax: +31 50 3614873.
Albert J.H. Suurmeijer
- Department of Pathology and Laboratory Medicine, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
Pieter L. Jager
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
Bernard F.A.M. van der Laan
- Department of Otorhinolaryngology – Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
Philip H. Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands

Received 4 June 2009; received in revised form 10 July 2009; accepted 10 July 2009. published online 19 August 2009.

Summary

The evaluation of response to radiotherapy in patients with laryngeal cancer is a challenge because of the difficulty to differentiate between post-therapy changes and recurrent or residual tumor. Positron emission tomography is a non-invasive imaging tool that may be helpful in this differentiation. In this study, [¹⁸F]-fluoro-3′-deoxy-l-thymidine ([¹⁸F]FLT), a proliferation tracer is compared with 2-[¹⁸F]-fluoro-2-deoxy-d-glucose ([¹⁸F]FDG).

Patients with primary laryngeal cancer, scheduled to undergo radiotherapy were included in this study. Patients underwent both [¹⁸F]FLT-PET and [¹⁸F]FDG-PET shortly before radiotherapy. Ten patients underwent [¹⁸F]FLT-PET and [¹⁸F]FDG-PET 2–3months after radiotherapy. Scans were analyzed visually for areas of increased tracer uptake. The standardized uptake value (SUV) was measured as a semi-quantitative value of tracer uptake.

Fourteen patients, all male, were included in this study. Both [¹⁸F]FLT-PET and [¹⁸F]FDG-PET showed increased tracer uptake in 12 out of 14 patients (86%). [¹⁸F]FDG uptake was significantly higher than [¹⁸F]FLT uptake (SUV_max: 4.5 vs. 2.4 (P=0.002); SUV_mean: 3.4 vs. 1.9 (P=0.002)). After radiotherapy, 3 patients had histologically proven residual or recurrent laryngeal cancer. [¹⁸F]FDG was true positive in 2 out of 3 patients, whereas [¹⁸F]FLT showed increased tracer uptake in only one. Of the remaining 7 patients, [¹⁸F]FLT was true negative in all, whereas [¹⁸F]FDG showed increased uptake in one (false positive).

[¹⁸F]FLT-PET is feasible in visualizing laryngeal cancer and its evaluation of treatment. The overall uptake of this tracer is significantly lower as compared with [¹⁸F]FDG, but tumor to background ratios are comparable.

Keywords: [¹⁸F]FLT-PET, [¹⁸F]FDG-PET, Positron emission tomography, Laryngeal cancer, Therapy evaluation, Radiotherapy