松果体部腫瘍の放射線治療，そのヨード油脳室造影による経時的追跡

RADIOTHERAPY OF PINEAL TUMORS:Assessment of Its Effect with Consecutive Oil Ventriculography

I．はじめに

　松果体部腫瘍の治療法として，その大部分を占めるpinealonnaが放射線感受性が高いところから，臨床的に診断し，減圧＋放射の姑息的療法をまず行なうものが多い。しかし現に照射を始めた松果体部腫瘍果してradiosensitiveか否かを他覚的に判定する方法に乏しく，個々の症例において線量，照射期間を決定するのに困難を感ずることが少なくない。

　そこで著者らは減圧手術後照射に先立つて油性造影剤を第3脳室内に注入し，照射期間中および照射後も経時的に松果体部腫瘍陰影の形状を観察追跡して見た。この方法によつて照射が有効かどうかをin vivoに判定することがてき，また照射に対する松果体部の腫瘍の反応は個々の例でかなり異なり，照射後一時症状の改善が認められたものの，3,475Rの照射で致死量となり部検により腫瘍組織の完全消失と瘢痕化の認められた症例なども経験されたので，画一的照射は慎まなければならないことがわかつた。

The radiotherapy following shunting procedure is regarded superior to the radical surgical therapy of pineal tumors. On the value of the radiotherapy of these, several statistical and histological studies have been raised in literature, however, the objective confirmation of its effectiveness during irradiation course has been seldom reported.

We have treated 8 cases of clinically diagnosed pineal tumors with ventriculoauriculostomy followed by Cobalt 60 irradiation.

In 5 of them we have tried to observe, in vivo, the reducing process of the tumors during and after irradiation by the consecutive ventriculography with Myodil (Glaxo). Prior to the irradiation Myodil was instilled into the third ventricle, which clearly re-vealed the contour of the tumor and obstruction of the aqueduct of Sylvius in all 5 cases. The shape and volume of the contrast medium were observed consecutively through clinical course corresponding with the total depth dose of the irradiation.

Improvement of the symptoms was remarkable and the contour of the tumor became gradually re-duced through irradiation in every cases. And be-sides, in 3 cases the contrast medium passed away from the third ventricle into the spinal canal, suggesting the opening of the aqueduct of Sylvius. The time of passing away of the contrast mediumwas varied case to case ; that was seen in the mid-stage of irradiation in 2 cases (1,950R, 3,475R res-pectively), and was delayed as late as 13 months after the irradiation with total dose of 4,750R in a case. Even in a case of teratoma which was re-vealed by direct operation 2 months after the irra-diation, a certain reducing of the tumor was ob-viously observed on the consecutive oil ventriculo-grams but opening of the aqueduct of Sylvius was not obtained until the operation. Myodil also pass-ed away from the third ventricle in a girl with panhypopituitarism, who was much alleviated but died unexpectedly a week after the irradiation of 3,475R. Autopsy revealed no tumor rest anywhere.

It was emphasized that uniform irradiation should not be done, as radiosensitivity of individual tumors was remarkably different.