Long-term follow-up after parathyroidectomy for radiation-induced hyperparathyroidism.

BACKGROUND External radiation is associated with a risk of hyperparathyroidism. We reviewed the outcomes after operation for radiation-induced hyperparathyroidism (R-HPT). METHODS We conducted a retrospective review of all patients who had operative therapy for R-HPT from 1980 to 2003 in our department with a minimum of 3 years of follow-up after operative therapy. RESULT Between 1980 and 2003, 1932 patients underwent parathyroidectomy for primary hyperparathyroidism. Thirty-seven (1.92%) patients had a history of neck irradiation. Thirty-two patients underwent a bilateral exploration (BE), and 5 patients had a focused approach (FA). Thirty-five patients presented with single gland disease, and 2 patients had multiple gland disease. In the BE group, 26 patients remained cured biochemically after a median follow-up of 10.3 years (range, 3-21 years), and 6 patients had recurrence after a median of 13.2 years (range, 7-22 years). In the FA group, all 5 patients remained cured biochemically; however, the median follow-up remained shorter (6.4 years; range, 3-8 years). CONCLUSION In R-HPT, the incidence of multiple gland disease at the time of initial operation was comparable with sporadic HPT. In the absence of thyroid disease, an FA may be proposed for R-HPT. Metachronous pathologic glands may develop several years after successful parathyroidectomy in R-HPT. Hence, lifelong follow-up of these patients is essential.