L-1-11C-tyrosine PET in patients with laryngeal carcinomas: comparison of standardized uptake value and protein synthesis rate.
PET with L-1-(11)C-tyrosine (TYR) can measure and quantify increased protein synthesis in tumor tissue in vivo. For quantification of the protein synthesis rate (PSR), arterial cannulation with repeated blood sampling to obtain the plasma input function and a dynamic TYR PET study to calculate a time-activity curve are necessary. In most PET studies the standardized uptake value (SUV) method is used to quantify tumor activity. The SUV can be calculated without repeated arterial blood sampling and prolonged scanning time, as required for determination of the PSR. The relationship between PSR and SUV is largely unknown and different factors can cause wide variability in the SUV. Therefore, the comparison of the absolute quantification method (PSR) with the SUV method is obligatory to determine the possible use of noninvasive PET in head and neck oncology.


METHODS
Twenty-four patients with proven squamous cell carcinomas of the larynx (T1-T4) were studied using dynamic TYR PET. The PSRs of tumor and nontumor (background) regions were determined. Four different methods were used to calculate the SUV: uncorrected SUV (SUV(BW)); and SUVs corrected for body surface area (SUV(BSA)), for lean body mass (SUV(LBM)), and for the Quetelet index (SUV(QI)). Correlations between PSR values and SUVs were calculated.


RESULTS
The PSR of all tumors was significantly higher (P < 0.001) than the PSR of nontumor tissue. The correlations of SUV(BW), SUV(BSA), SUV(LBM), and SUV(QI) with the quantitative values of the PSR were high (r = 0.84-0.90). The best correlation was observed with the SUV based on the LBM (SUV(LBM)).


CONCLUSIONS
High correlation between the quantitative values (PSR) and the SUVs offers the possibility to use noninvasive TYR PET for detection and reliable quantification of primary head and neck tumors.
de Boer
Jurjan R
JR
Department of Otorhinolaryngology, Groningen University Hospital, Groningen, The Netherlands. j.r.de.boer@kno.azg.nl
Pruim
Jan
J
van der Laan
Bernard F A M
BF
Que
Tjin H
TH
Willemsen
Antoon T M
AT
Albers
Frans W J
FW
Vaalburg
Willem
W
D000368:Aged; D000369:Aged, 80 and over; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D002294:Carcinoma, Squamous Cell / Q000000981:diagnostic imaging* / Q000378:metabolism; D005260:Female; D006801:Humans; D007822:Laryngeal Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D014176:Protein Biosynthesis; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000493:pharmacokinetics
D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D014443:Tyrosine