Planning target volume (PTV) has been used to account for variations in tissue, patient and beam position. In oropharyngeal cancers, an isotropic expanded PTV has been used.

中文翻译：

---

设计旋转计划靶区对保留口咽癌患者咽缩肌的影响

规划目标体积 (PTV) 已用于解释组织、患者和光束位置的变化。在口咽癌中，已使用各向同性扩展 PTV。