Radiation effects on densities of mouse and tumour cells. The X-axis shows the numbers of days of177Lu-DOTA-Tyr3-octreotate treatment. The numbers of mouse and tumour cells were determined for a defined reference area in the centre of the tumour. Bars that are close together represent results from different sections of the same tumour. The numbers of tumour and mouse cells represent different tumours for the untreated group (n = 2), the 1-day-treatment group (n = 2), the 5-day-treatment group (n = 5), the 12-day-treatment group (n = 4), the 20-day-treatment group (n = 3), and the 150-day-treatment or regrown tumours group (n = 3).