Carbon-11 tyrosine PET for visualization and protein synthesis rate assessment of laryngeal and hypopharyngeal carcinomas

Abstract

Accurate assessment of tumour extent and lymph node involvement in squamous cell carcinomas of the head and neck region is essential for therapy planning. Unfortunately, conventional diagnostic examination and imaging techniques, which monitor tumours on the basis of anatomical parameters, have drawbacks in clinical practice. The aim of this study was to investigate the feasibility of L-[1-(11)C]-tyrosine (TYR) positron emission tomography (PET) for visualisation of squamous cell carcinoma of the larynx and hypopharynx and quantification of tumour activity by assessment of protein synthesis rate (PSR). Dynamic TYR PET was performed on 31 patients with T1-T4 laryngeal or hypopharyngeal carcinoma before therapy. Plasma activity of TYR, (11)CO(2) and (11)C-protein levels were measured, and PSRs were calculated for primary malignancies. All 31 laryngeal and hypopharyngeal tumours were visualised as a hotspot (sensitivity 100%). The median PSR of the tumours (2.06 nmol ml(-1) min(-1); range 0.72-6.96) was significantly higher ( P<0.001) than that of non-tumour (background) tissue (0.51 nmol ml(-1) min(-1); range 0.22-0.89). L-[1-(11)C]-Tyrosine PET appears to be a potential method for visualisation of primary laryngeal and hypopharyngeal tumours. In vivo quantification of tumour activity by assessment of PSR is possible and may have a future role in the therapy planning and therapy evaluation of laryngeal and hypopharyngeal tumours.

Imaging and cancer: A review

“…11 C‐TYR PET has been used for the visualization and protein synthesis rate assessment of laryngeal and hypopharyngeal carcinomas (De Boer et al., 2002). Head and neck cancer is a difficult area for 18 F‐FDG PET due to the presence of inflammatory regions.…”

18F-FET PET/CT in Advanced Head and Neck Squamous Cell Carcinoma: an Intra-individual Comparison with 18F-FDG PET/CT

“…Amino acids are specifically accumulated in malignant cells owing to increased expression of amino acid transporters. In contrast to glucose derivates, the uptake of amino acids in macrophages and other inflammatory cells is absent or at least reduced [3,4], therefore the amino acid tracers appear to be more specific for tumor than FDG. Promising results for the detection of HNSCC have been reported using L-methyl-[ 11 C]-methionine [5] and L- [1-(11) C]-tyrosine [3] as a tracer.…”

Is C‐11 Methionine PET an alternative to 18‐F FDG‐PET for identifying recurrent laryngeal cancer after radiotherapy?

“…The amino acid tyrosine (TYR) and O‐(2‐[18F] fluor ethyl)‐L‐tyrosine (FET) are the only radiopharmaceuticals that show results that are equal or better than those obtained with FDG for visualising recurrent or residual head and neck carcinomas. Unfortunately the laborious production processes are a serious limitation to using TYR and FET on a larger scale …”