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目的 对乳腺癌术后胸壁放射治疗几种常用照射技术的剂量分布特点进行研究。方法 对乳腺癌手术后患者和做了标记的测量体模 ,按放疗体位做CT扫描 ,CT影像经网络送入三维TPS ,在TPS上设计 4种照射方案 ,并在人体模上进行模拟照射 (参考剂量 1Gy) ,用热释光剂量仪进行实际测量。 结果 实验结果表明除电子线弧形旋转照射外 ,其它 3种照射技术的胸壁剂量都较均匀 (胸壁平均剂量 >0 .90Gy)。电子线弧形旋转照射和X线双切线野 +内乳区电子线野技术由于在内乳区设野保证了内乳区有充足的剂量 (内乳点剂量 >0 .90Gy) ,但是后者在 2个野交界处易形成剂量冷热点。单纯X线切线野和适形野技术在内乳区可产生欠剂量情况 ,体积剂量直方图显示电子线旋转照射技术肺部受高剂量照体积最小 ,适形野技术也使肺部受高剂量照射体积明显减小。在体表加盖 1.0～ 1.5cm的组织等效填充物后 ,4种照射技术的皮肤剂量都可提高到 0 .90Gy以上。 结论 乳腺癌胸壁照射技术有不同的剂量分布特点 ,在临床应用时应视患者具体情况选择使用
Objective To study the dose distribution characteristics of several commonly used radiation techniques for chest wall radiotherapy after breast cancer surgery. Methods CT scans were performed on patients undergoing breast cancer after surgery and labeled phantoms. CT images were sent to the three-dimensional TPS via the network. Four irradiation protocols were designed on the TPS, and simulated irradiation was performed on the human phantom ( Reference dose 1Gy), actual measurement with a thermoluminescence dosimeter. Results The experimental results showed that in addition to the electron beam arc rotating irradiation, the chest wall doses of the other three irradiation techniques were uniform (average chest wall dose >0.9Gy). Electronic wire arc rotation irradiation and X-ray double tangential field + inner breast field electron field technology due to the establishment of the field in the inner breast area to ensure adequate internal lactation dose (internal milk dose dose> 0.90Gy), but the latter Dose cold hot spots are easily formed at the two wild junctions. Simple X-ray tangential field and conformal field techniques can produce under dose conditions in the inner breast area. Volume dose histograms show that the electron beam rotating irradiation technique has the smallest volume of the lung irradiated by high doses, and the conformal field technique also makes the lungs receive high doses. The irradiation volume is significantly reduced. After covering the surface of the body with 1.0 to 1.5 cm of tissue equivalent filler, the skin doses of the four irradiation techniques can be increased to more than 0.90 Gy. Conclusion Breast cancer chest wall irradiation technology has different dose distribution characteristics. In clinical application, it should be selected according to the specific conditions of patients.