乳腺癌根治术后胸壁放疗技术与剂量分布

Chest wall radiotherapy technique and dose distribution for patients of breast cancer after radical mastectomy

乳腺癌根治术后病人CT图像送入三维治疗计划系统，观察6 MV X线切线照射及电子线垂直照射胸壁时的剂量分布。包括内乳淋巴结和不包括内乳淋巴结的6 MV X线切线照射无需楔形板；单纯电子线垂直照射，即使是6 MeV低能电子线，肺组织受照亦相当严重；6 MeV电子线配合皮肤表面填0．5 cm厚组织等效物，肺组织受照较小，皮肤剂量提高，但内乳淋巴结与其表面皮肤剂量不能两者兼顾；9 MeV电子线配合皮肤表面填不等厚度组织等效物，可使得90％等效剂量包括皮肤、胸壁和内乳淋巴结而肺组织受照很少；对皮肤和内乳淋巴结均需高量照射者，电子线配合皮肤表面填组织等效物垂直照射较X线切线照射有明显优势。

：Sending the CT images of the patients of breast cancer after radical mastectomy to CADPLAN 3D TPX, studying the dose distribution of 6 MV X－ray tangential irradiation and different energy electron ray perpendicular irradiation to chest wall． Xome results were presented． Including or not including the intramammary lymph． It is not necessary for 6 MV X beam tangential irradiation to chest wall of the patient of brest cancer after radical mastectomy． Perpendicular irradiation by 6 MV electron beam only, the irradiation of the lung is serious and the dose of the skin is low． Perpendicular irradiation by 6 MV electron beam with 0．5 cm bolus as compensator, it can reduce the irradiation of the lung and make dose of the skin high, but it will reduce the dose of intramammary lymph if above it the skin is overlaid of bolus． Perpendicular irradiation by 9 MeV electron beam with unequal thickness bolus overlaid on the skin, it can make 90％ isdose line involving the skin, chest and intramammary lymph but the lung which is irradiated is small． If both skin and intramammary lymph need high dose irradiation, perpendicular irradiation by electron beam with bolus as compensator has the significant superiority than X beam tangential irradiation．