Labels:text | screenshot | black and white | black | font | document OCR: hat has A major and definite aetiological factor to the been demonstrated is ionising radiation centres, in thyroid gland, given, in the past in som ildren. non- sterilising dosages to infants and c arcinoma Doses reported to have induced thyroid o epilate to 15Gy vary from a few Gy (1Gy=100 rad) given the scalp in the treatment of ring- worn us glands (1,500 rad) for the treatment of tubercul ophylactic in the neck. Other conditions include p also irradiation of the thymus in infants and tonsils, therapeutic irradiation of acne, enlarged Hodgkin's skin tumours of the head and neck, and ervical and non-Hodgkin's lymphomas of the lymph nodes.