Breast I-131 Uptake in a Postpartum Woman with Thyroid Cancer: A Case Report

Background: I-131 uptake in the breast could be occasionally observed in differentiated thyroid cancer who received I-131 scintigraphy or therapy. Herein, we report a postpartum patient with papillary thyroid cancer with breast uptake who received I-131 therapy. Case Report: A 33-year-old postpartum woman with thyroid cancer received 120mCi(4440MBq) I- 131 therapy 5 weeks after she ceased to breastfeed. The second day after ingestion of I-131, wholebody scintigraphy demonstrated asymmetric and marked uptake in bilateral breasts. The radiation dose of I-131 in the lactating breast would decrease rapidly by reducing the activity of breasts and expressing breast milk with an electric pump once daily. Results: The sixth day after administration, scintigraphy demonstrated weak uptake in bilateral breasts. Conclusion: Physiologic I-131 uptake in the breast could occur in a postpartum woman with thyroid cancer who received I-131 therapy. In this patient, we find that the radiation dose of I-131 accumulated in the lactating breast would decrease rapidly through reducing the activity of breasts and expressing breast milk with an electric pump, which may be a better choice for the postpartum patient who was not given lactation-inhibiting medications and had I-131 therapy.