A Ukrainian woman, who was exposed to radiation from the Chernobyl nuclear power plant explosion, rests after her thyroid cancer was removed, in a hospital in Kiev April 6, 2006. Ukraine prepares to mark the 20th anniversary of the world's worst nuclear disaster on April 26 when a reactor at the Chernobyl power plant exploded, spreading a radioactive cloud across Europe and the Soviet Union. There was a dramatic increase in thyroid cancer among people living in the region and millions across Europe have suffered health problems, many of them children. REUTERS/Damir Sagolj