A new approach to therapy can avoid most of the debilitating effects of preparing for critical, postsurgical treatment for patients with thyroid cancer, according to an international study led by researchers from Johns Hopkins and the University of Pisa. Using a genetically engineered thyroid stimulating hormone (TSH) - called thyrotropin alfa, or rTSH - doctors were able to ablate, or destroy, the small amount of thyroid gland tissue that often remains after thyroidectomy, without the need to temporarily withhold thyroid hormone medication. This new approach also avoided the temporary but troubling symptoms flowing from the deficiency of thyroid hormone (or hypothyroidism), such as fatigue, weight gain, chilliness, slowed thinking, depression, constipation and muscle cramps.