방사선 조사가 백서 설조직에 미치는 영향에 관한 실험적 연구

Abstract

[한글]

저자는 두경부 악성종양 치료를 위한 방사선조사가 정상 설조직에 미치는 영향을 관찰하기 위하여, 생후 3-4개월된 체중 180gm내외의 백서 (Sprague-Dawley strain) 60마리를 대조군, 실험군 제1, 2, 3군으로 각각 15마리씩 나누어, 1.25 MeV RAC-120 Cobalt 60 치료기를 사용하여, 조사거리 100cm에서 매분당 72.6rad로 실험군 제1군에서는 총조사량 2650rad를 매주 530rad씩 5회 분할조사, 제2군에서는 2400rad를 매주 800rad씩 3회 분할조사, 제3관에서는 1500rad를 단회조사하여, 조사 완료후 3일, 1주, 2주, 3주, 4주간격으로 3마리씩 회생시켜, 적출한 조직을 10% Formalin용액에 고정후 400 Formic acid로 탈회하고, Paraffin에 포매한 후, 6μm두께로 연속 절편하여 Hematoxylin-Eosin에 중염색한 후 광학현미경으로 검경한 결과, 다음과 같은 결론을 얻었다.

1. 분할 조사군인 제1, 2군에서, 상피조직의 이형성은 3일 소견에서 가장 심하며, 1주에서는 다소 경미하였고, 2주 이후에서는 정상조직과 유사한 소견을 보였다.

2. 단회조사군인 제 3군에서 상피조직의 이형성은 분할조사군에 비해 경미하였으며, 이는 단회조사가 분할조사에 비해 조직에 미치는 위해 영향이 미약함을 나타내준다.

3. 고유층의 변화 즉 부종 및 염증반응도 각 군 공히 3일, 1주에서는 현저하였으나, 2주 이후에서는 회복되는 경향을 보였다.

4. 혈관의 소견은 충혈 및 화장은 볼 수 있었으나, 내피세포 증식 및 혈관 폐쇄 현상등은 관찰할 수 없었다.

5. 설의 부위에 따른 소견은 측면이 배면에 비해 심한 부종 및 염증반응을 나타내었고, 배면에서는 관찰되지 않은 조직의 괴사 및 궤양 형성을 보였다.

6. 방사선조사에 의한 상피조직의 이형성(Dysplasia)은 전암병소의 병리 조직학적 소견과 유사하며, 이는 방사선 위해 작용이 계속 축적될 경우 전암병소로 이행될 가능성이 있음을 의미한다.

7. 두경부 악성종양의 방사선 치료시 설조직을 포함한 구강 정상조직에 대한 방사선 방어제의 사용과 식이 보조요법이 필요하리라 사료된다.

[영문]

This study was undertaken to observe the histologic changes in tongue of the albino rats when exposed to single and fractionated dose of Cobalt-60 irradiation.

Sixty albino rats of a Sprague-Dawley strain, weighing approximately 180gm, about 3 to 4 month old, were divided into the control group and 3 experimental groups.

Irradiation was carried out using 1.25 MeV RAC-120 Cobalt-60 Teletherapy unit with exposure dose rate 72.6 rads/min., in TSD 100cm. In experimental groups, Group Ⅰ was irradiated 530 rads weekly of total dose 2650 rads for a period of 5 weeks, Group Ⅱ was irradiated 800 rads weekly of total dose 2400 rads for a period of 3 weeks and Group Ⅲ was irradiated 1570 rads with single dose.

The animals were sacrificed at 3rd day, 1st week, 2nd week, 3rd week and 4th week after each irradiations.

Each specimens were fixed with 10% Formalin sol. and decalcified in 40% Formic acid sol. The specimen was embedded in Paraffin and sectioned serially at 6μm in thickness.

All slides were stained with Hematoxylin-Eosin and examined in the usual methods.

The results were as follows.

1. The most severe epithelial dysplasia was seen in the 3rd day findings and the mild sign was in the 1st week findings and it was almost similar to normal tissues in the following 2nd week findings in Group Ⅰ and Ⅱ.

2. So long as the epithelial dysplasia was concerned, the single dose, Group Ⅲ showed much slighter change than that of the fractionated dose, Group Ⅰ and Ⅱ and, so was in tissue injury.

3. The histologic changes of edema and inflammatory response in the lamina propria were remarkable in the 3rd day and the 1st week findings in each experimental groups.

However there was tendency to recover in the following 2nd week findings progressively.

4. As to the vascular changes, there were the vascular congestion and dilation, neither the endothelial proliferation nor the vascular obliteration were seen.

5. There were remarkable signs of active inflammatory changes, edema, necrosis and ulceration in the lateral surface of tongue as compared with the dorsal surface of tongue, whereas there were neither necrotic changes nor ulceration in the dorsum of tongue.

6. Epithelial dysplasia due to irradiation shows histopathologically very similar findings to precancerous lesion and it is thought to be possible to be transformed into malignancy with the accumulative effects of radiation injury on tissues.

7. It is considered that the utilization of radiation protective agent for the protection of normal oral tissues including tongue and the supportive alimentotherapy are necessary in the radiation therapy for head and neck malignancy.