基礎的研究で15病変のice ballの視認性を検討し、軟部腫瘍では全病変で明瞭(CT値が0HU前後まで低下)が、骨腫瘍では明瞭から全く不明まで分散(CT値>130HU)。ice ballに対する腫瘍壊死の容積率は平均74%。
臨床試験は20例(男性15女性5、平均64.8才;52-85、平均最大腫瘍径2.9cm;1.0-4.7)を登録。主要評価項目の安全性では 2例(10%)にGrade-3末梢神経障害の重篤な合併症が出現。副次評価項目で、有痛性3症例においては全例(100%)で除痛効果が得られて無痛となり、局所腫瘍壊死率は19例(95%)でCRまたはPRが得られ、5年生存率は27.4%。
This prospective study enrolled 20 subjects (15 male, 5 female) with mean age of 64.8 years (range, 52-85 years) having malignant musculoskeletal tumors with a mean maximum diameter of 2.9 cm (range, 1.0-4.7cm). No adverse event was found in 18 of 20 patients (90%). Grade-3 peripheral nervous system disorder was fund in 2 patients (10%, 2/20). NRS scores fell down to 0 in 3 of 3 patients (100%) who had painful musculoskeletal tumors. Tumor response (complete or partial response) was achieved in 19 of 20 patients (95%) during follow-up period. The 5-year overall survival rate and the median survival time were 27.4% and 4.4 years, respectively.
In conclusion, cryoablation for musculoskeletal tumors is relatively safe, feasible, and useful therapeutic option for controlling tumors and for relieving pain, which can engender prolonged patient survival.