目的:詳細討論何杰金氏病放射治療方法與劑量計算過程，並討論其臨床上實用性。材料與方法:針對本院一18歲何杰金氏病男性病人，討論斗蓬照野、倒Y型照野Clarkson劑量計算方法，並利用治療計畫做追加照射(boost)劑量推定，及估算兩照野間距若干。討論:劑量計算之誤差主要來自體表不平整性，誤差約6%。而斗蓬照野中之肺與其他組織之不均勻性，由於肺部經鉛檔塊遮檔，對於照野範圍內之劑量計算不造成任何影響。體表肋骨之影響,誤差在1%以內，可以忽略。結論:Clarkson方法為計算不規則照野劑量之可行方法，唯其費時費力，故電腦化或製作換算樣版以提高臨床實用性是必須的。

　　　　　Purpose: Discussing the dose evaluation process for Hodgkin's disease radiotherapy andthe clinical practice. Materials and Methods: Using the Clarkson's 's method to evaluate mantle andinverse Y fields dosimetry for a eighteen-year-old Hodgkin's disease patient in our hospital, andestimate the boost dose from treatment planning, otherwise, calculate the gap between two adjacentfields.Discussion: The main error of dose evaluation came from the non-flatteness of body, which up to6%. Since lung was blocked, the inhomogeneity between lung and adjacent tissue in the mantlefield caused on effect to dose evaluation. The rib's effect which within 1% is negligible.Conclusion: Clarkson's method is a useful way to evaluate the dose of irregular fields, but it is timewasting and laborious. Computerization or equivalent squares template may be applied to increaseclinical practice.