Steeves R A, Murray T G, Moros E G, Boldt H C, Mieler W F, Paliwal B R
Department of Human Oncology, University of Wisconsin, Madison 53792.
Int J Hyperthermia. 1992 Jul-Aug;8(4):443-9. doi: 10.3109/02656739209037982.
Ferromagnetic (FM) thermoseeds and radioactive (125I) seeds were combined in an episcleral plaque to give concurrent hyperthermia and irradiation for enhanced tumour destruction. A Greene melanoma cell line was utilized to study the interaction between these treatment modalities. We attached five FM thermoseeds (with an operating temperature of 48 degrees C) in parallel with alternating rows of 125I seeds onto the inner surface of each 14 mm Silastic plaque. Plaques were centred over a 3-6 mm (diameter) intraocular melanoma in each rabbit. Some rabbits were then placed within a heating coil, and their eye tumours were warmed rapidly to therapeutic temperatures (43.6 degrees C across the tumour base) while the temperature of normal conjunctiva across the globe did not exceed 38.5 degrees C. Analysis of 49 treated eye melanomas showed 50% local tumour control at 41.7 Gy for 125I alone, whereas only 9.5 Gy were needed to give the same local control rate after 125I with concurrent FM hyperthermia. Thus, a thermal enhancement ratio of 4.4 was obtained. Hyperthermia alone gave a 20% tumour response rate, but responses were only temporary. We conclude that FM thermoseeds can be used to deliver biologically effective hyperthermia concurrently with radiation, thereby reducing the dose of radiation needed for tumour control.
将铁磁（FM）热籽和放射性（125I）籽结合于巩膜外斑块中，以同时进行热疗和放疗，增强肿瘤破坏效果。利用格林氏黑色素瘤细胞系研究这些治疗方式之间的相互作用。我们将五颗FM热籽（工作温度为48摄氏度）与交替排列的125I籽平行附着在每块14毫米硅橡胶斑块的内表面。将斑块置于每只兔子眼内直径3 - 6毫米的黑色素瘤上方中央位置。然后将部分兔子置于加热线圈内，其眼肿瘤迅速升温至治疗温度（肿瘤底部温度为43.6摄氏度），而眼球表面正常结膜的温度不超过38.5摄氏度。对49只接受治疗的眼黑色素瘤进行分析显示，单独使用125I时，41.7戈瑞的剂量可实现50%的局部肿瘤控制，而在125I联合FM热疗后，达到相同局部控制率仅需9.5戈瑞。因此，获得了4.4的热增强比。单纯热疗的肿瘤反应率为20%，但反应只是暂时的。我们得出结论，FM热籽可用于在放疗的同时提供具有生物学效应的热疗，从而降低控制肿瘤所需的放疗剂量。
