Some Observations and Problems of Treatment with Radioactive Iodine I131

Publisher Website
Google Scholar
Abstract
Since the end of 1947 a series of 18 cases of thyroid carcinoma have been investigated at the hospital using tracer doses of radio-iodine I131, and of these one was found to concentrate I131 in metastatic deposits that were known to be present. The percentage uptake was such that an attempt to carry out treatment using larger amounts of the isotope was made. This paper is a clinical report upon this case, and whilst a cure is not claimed, it illustrates some of the problems which may arise in this new method of treatment, together with some conclusions which may be drawn from a study of the physical data. After our preliminary tracer studies it was decided that thyroidectomy would be desirable before giving doses of I131 sufficient to treat the metastases. Our reasons for this were threefold. Firstly, it was feared that a high percentage concentration of a large dose of the isotope in the thyroid might lead to a thyrotoxic crisis, as has been reported by Trunell et al (1947). Secondly, irradiation effects on neighbouring structures might also occur because of the high thyroid uptake, as has been reported in experimental animals (Gorbman, 1947). Finally, total thyroidectomy is reported to increase differentiation and iodine uptake in metastatic deposits (Rawson et al., 1948). In our case the patient was unwilling to submit to further operation, and thyroid ablation was carried out by giving an amount of radio-iodine which was calculated to avoid the first two dangers outlined above.