방사선과 분할온열요법 병행시 열증강율의 변동에 관한 실험적 연구

Abstract

溫熱療法이란 組織의 加熱時에 發生하는 細胞 生産學的 效果를 癌治療에 應用한 것으로 單獨, 分割溫熱療法으로 또는 放射線照射와 竝行해서 쓰이고 있다. 그러나 分割溫熱療法의 경우, 1次加熱 後 熱抵抗이 생겨 再次加熱時 熱에 대한 細胞의 感受性이 떨어지며 이는 溫熱 效果를 얻는데 障碍要素가 된다. 反面 放射線과 溫熱療法 竝行時 放射線 單獨療法에 비해 放射線 效果가 增加되며 이를 熱增强率이라 한다. 그러므로 放射線과 分割溫熱療法 竝行時 1次加熱에 의해 發生된 熱抵抗이 再次加熱 및 放射線 效果, 즉 熱增强率의 發生에 影響을 주게 될 것으로 思料된다. 本 實驗은 放射線과 分割溫熱療法 竝行時 分割間隔時間別 熱增强率의 變動狀態를 觀察하고자 總 330마리의 마우스를 溫熱療法 實驗을 위한 第1對照群 72마리와 放射線 單獨療法實驗을 위한 第2對照群 36마리 및 放射線과 溫熱療法 竝行實驗을 위한 主實驗群 222마리로 大別하여 實驗한 後 다음과 같은 結論을 얻었다. 1. 單一溫熱療法時 50% 壞死時間（ND50）은 43℃에서 101分, 45℃에서 24分으로 加熱時間은 溫度의 上昇에 反比例하였다. 2. 分割溫熱療法時 1次加熱에 의해 뚜렷한 熱抵抗이 發生함을 觀察하였으며 이는 2次加熱 效果를 減少시켰다. 3. 放射線 單獨療法時 皮膚反應은 照射量에 比例하여 增加하였고, 皮膚反應點數 1.5에 해당하는 照射量（D1.5）은 4,137rads였다. 4. 放射線과 單一溫熱療法 竝行時 현저한 熱增强率을 觀察하였으며 加熱時間의 增加에 따라 熱增强率도 比例的으로 上昇하였다. 5. 放射線과 分割溫熱療法 竝行時 熱增强率이 顯著히 低下되었으며 그 程度는 熱抵抗 現象에 비해 적게 減少되었으나 더 오래 持續되어 뚜렷한 差異를 나타내었다. 以上의 成績을 요약하면, 熱增强率의 變動은 熱抵抗 現象에 影響을 받고 있는 것으로 判斷되며 이 結果는 向後 放射線과 分割溫熱療法 竝行의 效能에 關한 硏究의 基礎資料가 될 수 있을 것으로 思料된다. ; The study was undertaken to evaluable the alteration of thermal enhancement ratio as a function of time intervals between two split dose hyperthermias followed by irradiation. For the experiments, 330 mice were divided into 3 groups; the first, 72 mice were used to evaluate the heat reaction by single dose hyperthermia and heat resistance by split dose by hyperthermia, the second, 36 mice were used to evaluate the radiation reaction by irradiation only, and the third, 222 mice were used for TER observation by combination of single dose hyperthermia and irradiation, and TER alteration by combination of split dose hyperthermia and irradiation For each group the skin reaction score of mouse tail was used for observation and evaluation of the result of heat and irradiation. The results obtained are summarized as follows: 1. The heating time resulting 50% necrosis（ND50）was 101 minutes in 43℃ and 24 minutes in 45℃ hyperthermia , which indicated that there is reciprocal proportin between temperature and heating time. 2. Developing of heat resistance was observed by split dose hyperthermia. 3. The degree of skin reaction by irradiation only was increased proportionally as a function of radiation dose, and calculated radiation dose corresponding to skin score 1.5（D1.5）was 4,137rads. 4. Obtained thermal enhancement ratio by combination of single dose hyperthermia and irradiation was increased proportionally as a function of heating time. 5. Thermal enhancement ratio was decreased by combination of split dose hyperthermia and irradiation, which was less intense and lasted longer than development of heat resistance. In summary, these studies indicate that the alteration of thermal enhancement ratio has influence on heat resistance by split dose hyperthermia and irradiation.