Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21231-2410, USA.
Int J Radiat Oncol Biol Phys. 2011 May 1;80(1):161-8. doi: 10.1016/j.ijrobp.2010.01.071. Epub 2010 Nov 19.
To assess volumetric changes of selected organs at risk (OAR) during intensity-modulated radiotherapy (IMRT) for oropharyngeal carcinoma.
Twenty-six consecutive patients that were treated with definitive IMRT ± chemotherapy between November 2007 and November 2008 were selected for the present study. As part of an internal quality assurances program, a repeat kilovolt (KV) computed tomography was planned weekly during the 7-week treatment course. On each available scan, a single observer contoured the parotid submandibular, and thyroid glands (PG/SMG/TG), larynx (L), and constrictor, masticatory, and sternocleidomastoid muscles (CM/MM/SCM) as appropriate. The volume at each scan was compared with the one at planning CT in a pair-wise fashion. p values <0.05 after correction for multiple testing were considered significant.
A total of 159 scans was obtained during treatment for a total of 185 scans, including the baseline imaging. All OARs showed statistically significant changes over baseline by week 5. At week 7, the PG showed the largest absolute change with an average reduction of ∼10 mL followed by both the SCM and MM (∼-5 mL). The largest (∼-30%) relative change was observed for the salivary glands. L and CM showed a ∼15% increase in volume during treatment.
All selected OAR undergo significant volumetric changes during a course of IMRT for oropharyngeal squamous cell carcinoma.
评估口咽癌调强放疗（IMRT）过程中危及器官（OAR）的体积变化。
本研究选择了 2007 年 11 月至 2008 年 11 月期间接受根治性 IMRT±化疗的 26 例连续患者。作为内部质量保证计划的一部分，在 7 周的治疗过程中每周计划进行重复千伏（KV）计算机断层扫描。在每次可获得的扫描中，一位观察者适当地对腮腺、下颌下腺和甲状腺（PG/SMG/TG）、喉（L）、以及缩咽肌、咀嚼肌和胸锁乳突肌（CM/MM/SCM）进行轮廓勾画。以成对的方式将每次扫描的体积与计划 CT 上的体积进行比较。经多次检验校正后，p 值<0.05 被认为具有统计学意义。
在治疗过程中总共获得了 159 次扫描，总共获得了 185 次扫描，包括基线成像。所有 OAR 在第 5 周时与基线相比均显示出统计学上的显著变化。在第 7 周时，PG 显示出最大的绝对值变化，平均减少约 10 毫升，其次是 SCM 和 MM（约-5 毫升）。唾液腺的相对变化最大（约-30%）。L 和 CM 在治疗过程中体积增加了约 15%。
在口咽鳞状细胞癌的 IMRT 治疗过程中，所有选定的 OAR 都会发生显著的体积变化。
