目的：探討硫酸亞鐵劑量計之原理，並研究其磁振 T?腕P弛率與吸收劑量之間的關係，並分析其在人體組織內吸收劑量反應與分佈的情形，最後也針對其在臨床放射治療應用上之可行性做一嘗試與比較。材料與方法：配製硫酸亞鐵溶液於洋菜粉末中，隔夜並待凝固後，置入線性加速器照射，最後經由磁振造影求出其 T ?腕P弛率，並進而研究其 T ?腕P弛率與吸收劑量之間的關係。同時也製作乳房相似假體與非均質組織來模擬肺部空腔假體，以分析其劑量分佈的情形，也與電腦治療計劃做一比較及分析。結果：硫酸亞鐵劑量膠體在磁振 T ?腕P弛率與劑量厲應，在劑量達 30 Gy 時仍呈直線關係。但由於磁振主磁場不均勻、膠體內離子擴散及降解作用等因素使得其信號與雜訊比仍未十分滿意。結論：硫酸亞鐵劑量計在三度空間立體劑量分佈上非常有用，尤其在乳房與胸空壁間之劑量分佈、組織密度不均勻之介面劑量分析上，有其臨床上應用的價值。但在提昇影像解析度、信號與雜訊比方面，仍有待更進一步的研究。[ 放射治療腫瘤學 1997; 4: 139-145 ]

　　　　　Purpose: To study howthe ferrous sulphate agarose gel reports the doseresponse and distribution to the mediums. The potential applications to clinicalradiation therapy are also introduced. Material and Method: Ferrous sulphateagarose gel containing ferrous ammonium sulfate, sodium chloride, sulfuric acidand triple distilled water was employed to measure dose distribution in themediums. The change for T ?? of the spin-lattice relaxation rates of ferric ionswith an MRI scanner was studied as a function of absorbed dose given to thegels. Breast-mimic gel phantom and inhomogeneous layer phantom were constructedto compare the 3D dose distributions in the gel phantoms with treatment planningdose distribution in these phantoms. Results: Thes dose response of the gel islinear up to 30 Gy. The degree homogeneity of the magnetic field, chemicaldiffusion and degradation of the gel are the major factors affecting the signalto noise ratio of the gel imaging. Conclusion: The gel may be applicable to 3Ddose verification in the areas of bone and air interface, breast and chest wall.However, the signal strength and resolution of the gel images are still notclinically satisfactory. Further studies to improve the above insufficienciesare needed. [Therapeut Radiol Oncol 1997; 4: 139-145]