転移性脊髄髄内腫瘍に対して放射線照射を行った3症例

Intramedullary Spinal Cord Metastasis Treated with Radiation Therapy: Report of 3 Cases

Ⅰ．はじめに

　転移性脊髄髄内腫瘍（intramedullary spinal cord metastasis：ISCM）は全悪性腫瘍の約2％程度と稀であり^2,6,9)その治療法は確立されていないが，癌治療に対する医療技術の発達に伴い，転移巣に対して治療を行う機会は今後増加すると予想される．

　これまでに同病に対し外科的治療を行った報告が散見されるが^5,9,12,13)，その生命予後は決して良好とは言えず，むしろ外科的侵襲による術後ADLの低下を考えるとその適応は慎重にならなければならない．一方，転移性脊椎・脊髄腫瘍に対しての放射線治療の有用性はこれまでにも多数報告され，神経症状の改善からADLの向上をもたらしている^2,4,8,10-12)．

　今回われわれは放射線単独で治療したISCM症例を経験したので，その治療経過や放射線照射の意義について報告する．

　Objectives Intramedurally spinal cord metastasis (ISCM) tends to be seen in the end period of the malignant tumor, so it is important to choose a therapeutic method regarding the QOL (quality of life) of the patient. In this study, we reported three cases of ISCM treated by radiation therapy alone, and demonstrated the utility of this therapeutic procedure.

　Patients and Methods From 2005 to 2006, 3 cases of ISCM underwent radiotherapy in our institution. The mean age of the patients was 64.0 years old, and all patients were men, having lung carcinoma as their primary lesions. The lesions were located at the cervical cord in one case and the conus medullaris in the other two cases. They were treated by radiotherapy at the department of radiology in our institute.

　Results The tumor size and intramedullary high signal area on MR images after the radiotherapy were reduced in all patients. During the clinical course, neurological symptoms were improved in two patients, and progression of the symptoms was stopped in one patient. All of the patients obtained a better ADL due to the radiotherapy.

　Conclusions Radiotherapy has an advantage over surgical treatment in that it involves less invasion. The treatment brought improvements of clinical symptoms and radiological findings in the patients with ISCM. So, radiotherapy could be used as one of the major treatments for patients with ISCM who desire a better QOL after treatment.