前言：晚期的會陰部腫瘤常會合併有腹股淋巴結的轉移，因此腹股淋巴結的治療對處理晚期的會陰部腫瘤佔有非常重要的角色。若放射治療給予腹股淋巴結足夠的輻射劑量及深度，控制率幾乎會和手術有一樣的效果且副作用較小。但治療太深以致於腹股溝的劑量太高時卻又有增加股關節骨折的危險。因此如何拿捏治療效用 (therapeutic ratio)，是用放射線來治療腹股溝淋巴結的重要課題。我們做了婦女腹股淋巴結深度的分析並探討可能較好的治療方式。材料及方法：我們隨機抽驗 65 位在放射腫療科接受放射治療的婦癌患者，檢視其四條股血管的深度來代表腹股淋巴結的可能深度。另外我們使用電腦計劃系統來計算不同能量的光子射線、電子射線及不比重之光子、電子之組合所得之劑量分布情況。結果：經過測量，65 位女病人的腹股淋巴結可能的深度，從 1 至 6.5 公分， 平均是 2.49 公分，中間值為 3.75 公分。 最深處從 2.5 至 8.8 公分，平均是 4.46 公分，中間值是 5.65公分。在治療 3 公分以下的深度，電子射線或許是不錯選擇。要治療 5 公分的厚度以上時，使用 10-12 MeV 電子射線合併 6 MV 光子射線， 可以在 5 公分後，劑量便下降了 205以上的能量，而能使股關節的輻射劑量不會太高。結論：腹股溝淋巴結的放射治療需要做個別的考量，因不同的厚度做不同方式的治療，以期達到最佳的治療效果，同時能有最小的副作用。[ 放射治療與腫瘤學 197; 4: 125-131]

　　　　　Purpose: Irradiation to inguinal lymph node had a very important role totreat advanced stage perineal tumor for it had high incidence of inguinal lymphnode metastasis. It needs great caution to irr adiate the inguinal area. Toirradiate with inadequate depth will cause poor control rate but too deep willlead risk of femoral head or neck fracture. We evaluate the depth of inguinallymph nodes and propose the possible better irradiation method. Material andMethods: We reviewed the CT films of sixty-five gynecological cancer patientswho received radiotherapy to find the possible depth of inguinal nodes - thedepth of four femoral vessels. We also calculated the irradiation dosedistribution by using different energy of photon beam, electron beam and variouscombination of photon and electron beams. Results: The most superficial depth ofinguinal lymph node ranged from 1 cm to 6.5 cm; the median was 3.75 and the menawas 2.49 cm. The most deep depth of inguinal lymph node ranged from 2.5 to 8.8cm; the median was 5.65 cm and the mean was 4.46 cm. Using the photon beam totreat the inguinal will cause too much radiation dose to femoral head area. Highenergy electron was a good choice to treat the lesion with 3 cm depth with outtoo much hot spot. To treat the depth of 5 cm, using the combination of 6MVphoton beam and high energy electron beam can get much homogenous dosedistribution but also can reduce more than 20% of dose to the femoral head area.Conclusion: It needs in dividual treatment plan according to the different depthto irradiate the inguinal lymph node area. To treat with appropriate depth withproper radiation modality not only can get good control but also to reduce thecomplication as much as possible. [Therapeut Radiol Oncol 1997; 4: 125-131]