孤立性リンパ節再発に対する重粒子線治療の成績

演　　者：

小此木 範之¹，山本 直敬¹, 山田 滋¹, 小藤 昌志¹, 今井 礼子¹, 村田 裕人¹, 辻 比呂志¹, 鎌田 正¹

所属機関：

¹放射線医学総合研究所病院・婦人腫瘍科

Background:
In recent years, there has been increasing recognition of that focal therapies contribute the clinical benefits for patients with oligo-metastases. This study retrospectively evaluated the treatment results of carbon-ion radiotherapy (C-ion RT) for lymph node (LN) oligo-recurrence.
Methods:
Eligibility criteria for this analysis were: the primary lesion of cancer was controlled; LN recurrence involved in a single lymphatic site; without recurrence other than LN; Patients who were 20 years of age or older; and C-ion RT for LN recurrence was given between December 1996 and December 2015 in our institution.
Results:
Two hundred fifty patients were matched to the eligibility criteria. The median follow-up period was 25 months. The detail of primary cancers was as follows; lung cancer (32%),lower gastrointestinal cancer (25%), uterus cancer (10%), pancreas cancer (7%), and others. The median dose of C-ion RT was 50.4 Gy (RBE) in 12 fractions. Forty-three patients had history of radiotherapy in the recurrent site. The 2-year local control (LC) rate, overall survival (OS) rete, and disease-free survival (DFS) rate after C-ion RT were 86%, 59%, and 31%, respectively. Although 10 patients developed grade 2 late toxicity, none of patients developed grade ≧3 late toxicity. Any factors including LN size, histology, history of previous RT did not show significance on univariate analysis for LC. Smaller number (≦3) of LN metastases (p = 0.047) was associated with a significantly better DFS. Smaller LN size (<30 mm) (p = 0.008) and longer disease-free interval (≧12 months) from primary therapy (p=0.006) were associated with a significantly better OS.
Conclusions:
This study demonstrated that C-ion RT could provide survival benefit for patients with LN oligo-recurrence. Patients who have small number of LN metastases (≦3), smaller LN size (<30 mm), and longer disease-free interval (≧12 months) were most likely to have survival benefit from C-ion RT.