Case Report of CyberKnife Radiosurgery Treatment for Secondary Hyperparathyroidism in a Patient Undergoing Dialysis

Introduction: We present a compelling case where CyberKnife effectively treated a patient suffering from bone pain and poor response to medication following a prior surgery for medullary thyroid carcinoma. Case Description: A 41-year-old patient who has been undergoing peritoneal dialysis combined with hemodialysis for 7 years, underwent a total thyroidectomy for medullary thyroid cancer 4 years ago. His iPTH levels rose to 1062.66 pg/ml, leading to bone pain in shoulders, wrists, and knees 2 years ago. Cinacalcet 50mg/day was prescribed, but iPTH levels remained uncontrolled, and bone pain persisted. MIBI imaging revealed a parathyroid nodule approximately 1.5*1.1cm in size on the right neck. Cyberknife treatment of 27Gy/3F was carried out. After 11 weeks of treatment, MIBI imaging showed reduced parathyroid volume and decreased uptake (Figure 1). The iPTH changes are detailed in table 1. No adverse events were reported during follow-up. Discussion: This is the first report of using Cyberknife to treat secondary hyperparathyroidism. After treatment, the patient's bone pain improved. MIBI imaging also indicated a decrease in parathyroid gland size and weakened uptake, suggesting treatment effectiveness. Further investigation is needed due to the limited experience in using cyberknife for SHPT. Prolonged observation is essential to assess efficacy and potential adverse effects.Figure 1. MIBI imaging before and after cyberknife treatment.Table 1. Changes of iPTH, calcium and phosphorus before and after cyberknife treatment.