A case of chemorefractory metastatic type AB thymoma sensitive to helical tomotherapy.

Type AB thymoma associated with multiple metastases is rarely encountered. This paper describes the therapeutic effect of new radiotherapy, helical tomotherapy (TOMO), in a thymoma patient with multiple metastases. A male patient aged 52 was diagnosed as type AB thymoma with multiple metastases. Two-cycle chemotherapy was administered as the primary therapy. The efficacy evaluation indicated progressive disease (PD), so radiotherapy was added to the initial treatment. The re-evaluation of efficacy indicated PD under chemotherapy and partial response (PR) in the radiotherapy area, so the latter treatment was changed to TOMO. The TOMO treatment was effective. However, due to the severe bone marrow suppression, the radiotherapy was stopped, and the patient was discharged. We concluded that the development of type AB thymoma associated with multiple metastases was fast, and the patient was sensitive to radiotherapy but not chemotherapy. Thus, TOMO can be selected as the primary palliative therapeutic regimen for chemotherapy-resistant thymoma patients, but the patient tolerance of TOMO requires careful evaluation and further clinical study.