仰卧位计划设计与俯卧位计划设计中肺体积受量的比较

摘要

Objective To compare CyberKnife doses based on lung volume determined with the patient in the supine or prone posi-tion in order to maximize efficacy of treating metastatic tumors in the spinous process of thoracic vertebra while minimizing damage to normal tissues. Method A total of 9 patients with metastatic tumors in the spinous process of thoracic vertebra were treated using CyberKnife dosing plans based on the supine or prone position,and outcomes were compared between the two approaches. Results Compared to the treatment based on the prone lung volume,treatment based on the supine lung volume required an additional 14,862-36,337 MU,lung V5 was 5.20-7.90 Gy higher,and lung V20 was 2.61-5.73 Gy higher. In addition,the treatment based on supine lung volume delivered-2.21-2.67 Gy more to the spine volume,-3.93-7.85 Gy more to the skin volume,and 0.28-6.39 Gy more to the esophagus. Conclusion Planning Cyberknife treatment based on the lung volume determined with the patient in the prone posi-tion may allow lower total radiation doses to be used and reduce exposure of adjacent healthy tissue.%目的：比较胸椎棘突部转移肿瘤予仰卧位与俯卧位射波刀计划设计的肺体积受量，为降低正常肺组织的损伤提供参考依据。方法选取胸椎棘突部转移肿瘤9例，分别采用仰卧位计划设计与俯卧位计划设计，比较两种计划设计中肺体积受量的变化。结果仰卧位计划设计与俯卧位计划设计比较，机器跳数多14862~36337 MU，肺V5高5.20~7.90 Gy，肺V20高2.61~5.73 Gy。脊髓体积剂量相差-2.21~2.67 Gy，皮肤体积受量相差-3.93~7.85 Gy，食管体积剂量相差0.28~6.39 Gy。结论俯卧位计划设计比仰卧位计划设计能更好地保护肺组织，提高射线的利用率。