Figure 1. ¹³¹I scintigrams of the head and thorax, anterior views. (a) 7 days after the first therapeutic dose, several cervical foci of ¹³¹I uptake and diffuse trapping in the lungs. (b) 4 days after the third therapeutic dose, persistence of one cervical focus and lung uptake. (c) Scintigram with 0.7 GBq of ¹³¹I 37 days after recombinant thyroid stimulating hormone (rTSH) and the third therapeutic dose: disappearance of ¹³¹I uptake at T1 and in the lungs, but the salivary glands and mediastinum are clearly radiolabelled. (d) 5 days after the fourth therapeutic dose: re-appearance of the radiotracer in both lungs and persistence of weak uptake in T1 despite surgery.