KINETICS OF [METHYL-C-11]THYMIDINE IN PATIENTS WITH SQUAMOUS-CELL CARCINOMA OF THE HEAD AND NECK

Thymidine labelled with a position emitter and imaging by positron emi ssion tomography has been suggested to measure tumour proliferation in vivo non-invasively. The present study presents a compartmental model which describes the behavior of [methyl-C-11] thymidine in tumour tis sue and allows quantification of the data using a proliferation parame ter (PP). In nine patients with squamous cell carcinoma of the head an d neck, C-11-activity over the tumour and the adjacent blood vessels w as measured. The median PP without correction for blood pool activity was found to be 8.61 10(-4) min(-1). With correction this parameter ch anged from - 14% to + 40%. We found no correlation between either sex or tumour differentiation and PP. The described model can be used to q uantitate [methyl-C-11]thymidine uptake in human tumours. Indivdual co rrection for tumour blood volume is mandatory.