Reconstruction using a frozen tumor-bearing vertebra in total en bloc spondylectomy can enhance antitumor immunity

Distant metastases from thyroid carcinoma are successfully cured if they take up radioiodine (I-131), are of small size, and located in the lungs. Bone metastases have the worst prognosis because I-131 therapy and external beam radiotherapy are less effective. Our propose here is to report a patient with solitary spinal metastasis and multiple lung metastases from thyroid carcinoma, whose spinal metastasis was treated by total en bloc spondylectomy (TES) enhancing antitumor immunity using frozen tumor-bearing bone for spinal reconstruction. The patient was a 37-year-old male who had solitary spinal metastasis at T4 and multiple lung metastases from thyroid carcinoma. I-131 therapy for the multiple lung metastases resulted in no effect because the apparent I-131 uptake was observed only in T4 metastasis. We performed a TES of T4 with cryotreatment. After en bloc excision of T4, the excised tumor-bearing vertebra was frozen by liquid nitrogen. In spinal reconstruction, the frozen vertebra was used in a mesh cage inserted into the anterior defect. After surgery, the thyroglobulin level decreased without any other adjuvant therapy and the serum levels of INF-gamma and IL-12 increased. This indicates antitumor immunity was activated. Then, I-131 therapy became effective to the lung metastases causing the tumors to decrease in size and number. Three years after surgery, progression in the lung metastases, other metastasis, and local recurrence have not been observed. TES with cryotreatment as presented is a novel surgery which can enhance antitumor immunity against other visible or non-visible metastases.