放射線治療が著効した転移性虹彩腫瘍の1例

Radiation therapy was very effective in a case of metastatic tumor of the iris

要約　目的：放射線治療が著効した転移性虹彩腫瘍の報告。症例と経過：肺腺癌に対し，2年前から化学療法を断続的に受けていた68歳男性が右眼の充血と視力低下で受診した。矯正視力は右0.3，左1.2，眼圧は右50mmHg，左15mmHgであった。右眼に虹彩毛様炎と虹彩の下鼻側に白色隆起性病変があり，転移性虹彩腫瘍と診断した。眼圧下降治療には反応しなかった。疼痛の訴えが強かったが，眼球温存を考慮し，眼球摘出ではなく放射線治療を選択した。6MeVのX線による三門照射で1日量3Gyを連日行い，総量42Gyとした。照射開始後，虹彩の腫瘍は次第に小さくなり，4か月後には完全に消失した。眼圧は下降し，疼痛はなくなった。結論：転移性虹彩腫瘍に対し，放射線治療は有用な選択肢の1つである。

Abstract.　Purpose：To report a case of metastatic iris tumor that improved after external radiation therapy. Case：A 68-year-old male had been diagnosed with adenocarcinoma of the lung two years before. He had been under intermittent chemotherapy. He sought medical advice for pain and blurring in his right eye. The visual acuity was 0.3 right and 1.2 left. The interocular pressure（IOP）was 50mmHg right and 15mmHg left. His right eye showed signs of iridocyclitis and a white mass in the nasal inferior sector of the iris. He was diagnosed with metastatic tumor of the iris. Clinical Course：The raised IOP was not responsive to hypotensive treatments. The ocular pain persisted. We elected radiation therapy instead of enucleation in order to save the eyeball. The affected eye received 3-port X-ray radiation at the daily dosis of 3Gy totaling 42Gy. The iris tumor responded to external radiation and disappeared 4 months later. IOP spontaneously returned to normal range. Conclusion：This case illustrates that external radiation may be effective for metastatic iris tumor.