G.S. Pant joined All India Institute of Medical Sciences (AIIMS), New Delhi, India in the year 1971 in Radiation Oncology. In 1985, he moved to nuclear medicine, where he worked in various faculty positions before being elevated to the position of Professor (Med Phys) in 2003. After retiring from AIIMS in October 2007, he worked at King Fahad Specialist Hospital (KFSH), Dammam, Kingdom of Saudi Arabia (KSA) in Medical Imaging department as a Consultant Medical Physicist and Head of Cyclotron for few years. He has experience of working in various disciplines of radiological sciences like Radiation Oncology, Radiology and Nuclear Medicine. He has visited several countries as an expert in Medical Physics (nuclear medicine) under the aegis of the IAEA and Indian government. He has several research publications to his credit and has edited few books including the present one.