The therapeutic effect of stereotactic γ-ray body radiation therapy for patients with asynchronous bilateral renal cell carcinoma

Objective To preliminarily evaluate the feasibility,therapeutic effect and normal tissue complications of stereotactic γ-ray body radiation therapy for patients with asynchronous bilateral renal cell carcinoma.Methods Nine patients with inoperable asynchronous bilateral renal cell carcinoma with a median time from the resection of the primary focus and discovery of the contralateral focus underwent stereotactic γ-ray body radiotherapy with OUR-QGD stereotactic γ-ray whole body therapeutic planning system.50％ isodose line,as the prescription dose line,was to cover the planning target volume (PTV) and the 70％ isodose line was to cover the gross target volume (GTV).Radiotherapy was delivered,with a single dose of 3-5 Gy per fraction,one fraction per day,5 fractions per week,and totally 10-17 fractions.The PTV edge total dose was 36-51 Gy,and the GTV edge total dose was 60-85 Gy.The patients were followed up for a median time of 24 months to evaluate the local control rate and overall survival rate.Results Of the 9 patients,1 presented complete remission (11.1％) and 4 partial remission (44.5％),with a total effective rate of 55.6％.The 1-,3-,and 5-year local control rates were 64.8％,43.2％,and 43.2％ respectively.The 1-,3-,and 5-year overall survival rates were 66.7％,53.3％,and 35.6％ respectively.Four patients (44.4％) had acute radiation reaction:2 cases with grade l leukocytopenia and 2 cases with grade 1 gastrointestinal reactions.Two patients showed grade 2 late radiation-induced reaction in gastrointestinal system.The Karnofsky score was significantly increased and the renal function was normal after radiotherapy.Conclusions Stereotactic γ-ray body radiation therapy is safe and effective in the treatment of asynchronous bilateral renal cell carcinoma. Key words: Renal cell carcinoma;  Stereotactic γ-ray body radiation therapy;  Asynchronous bilateral tumor