Preliminary Effect Of Cyber Knife Radiosurgery In The Treatment Of 42 Patients With Adrenal Metastases

Objective : There is no evidence supporting the use of any adrenal metastasis-directed therapy( surgery, radiotherapy, percutaneous catheter ablation or chemotherapy). Stereotactic body radiotherapy(SBRT) is an accurate radiotherapy with low split, large dose, real-time tracking of radiotherapy in the treatment of adrenal metastases.There is seldom report about it.The aim of this study is understand the local control, overall survival, progression-free survival and adverse reactions,to determine the effectiveness and safety of patients treated with stereotactic body radiotherapy(SBRT)-CyberKnife for adrenal metastases.Methods and Materials: A retrospective analysis of treatment details and outcomes for 44 patients with adrenal gland neoplasms treated by CyberKnife at CyberKnife center of Tianjin Medical University Cancer Institute and Hospital from October 2006 to December 2013 is presented.Short-term effect was observed after one months later, then patients were followed every 3 months.The observation end point was overall survival time(OS), local control of treated metastasis(LC) and disease progression-free survival(DPFS). WHO response evaluation criteria in solid Tumors RECIST1.1 was used to evaluate efficacy, RTOG / EORTC radiation injury grading criteria to evaluate treatment response, Kaplan-Meier method to calculate survival rate and local control rate and plot survival curves. Cox regression analysis was used to determine prognosticators for OS and LC.Results:There were 42 patients, 47 targets included in the study at the date of last follow-up. 14 lesions(29.8%) showed complete remission response, 13 lesions(27.7%) showed partial remission response, 12 lesions(25.5%) showed stable, 8 lesions(17.0%) progressed. Response rate was 57.4%, disease control rate was 83.0%,1-year local control rate was 86.6%, 2-year local control rate was 60.0%, the median disease progression free survival(DPFS) was 5.0 months. GTV less than 2500mm3, BED more than 80 Gy, older than 60 years could improve local progression-free survival(LPFS).All patients tolerate the radiosurgery well,fatigue and Gastrointestinal reactions being the main side effect. Only 1 patient appeared grade 3 Gastrointestinal reaction and no grade 4 or above toxicity was encountered. Conclusion CyberKnife seems to be a safe and effective treatment measure with slight adverse reaction and good local control rate for patients with adrenal metastases.However, CK is less invasive and may be more acceptable for patients. The result needs randomized trials to confirm and further study.