Damato Antonio L, Kassick Megan, Viswanathan Akila N
Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY.
Tufts Medical School, Boston, MA.
Brachytherapy. 2017 Sep-Oct;16(5):949-955. doi: 10.1016/j.brachy.2017.04.236. Epub 2017 Jun 12.
The aim of this study was to evaluate injection of a novel hydrogel (TraceIT; Augmenix, Waltham, MA) between the cervix, rectum, and bladder in female cadavers compared with, and in addition to, the current standard of gauze packing, for organ-at-risk sparing in cervical cancer brachytherapy planning.
This brachytherapy cadaver study used T2-weighted MRI and CT imaging to compare three scenarios: (1) gauze packing alone, (2) hydrogel injection placed in the cervical fornices and rectovaginal septum, and (3) gauze packing in conjunction with hydrogel injection. Hydrogel distribution was evaluated. Doses to 2 cm volumes (D) for the rectum, bladder, and sigmoid were collected. Statistical significance (p < 0.05) was evaluated using a two-tailed paired t test.
Hydrogel was successfully injected to space the bladder and rectum from the cervix in all five cadavers. The spacer was easily identifiable on both CT and MRI. The use of hydrogel in addition to packing resulted in a 22% decrease in rectum D dose (p = 0.02), a 10% decrease in bladder D (p = 0.27), and no change in sigmoid D dose. No difference was observed between hydrogel only vs. gauze packing only.
Our results revealed a significant clinically meaningful decrease in rectal D associated with the use of hydrogel in addition to gauze packing-TraceIT hydrogel holds promise as a spacer in cervical cancer therapy.
本研究旨在评估在女性尸体的子宫颈、直肠和膀胱之间注射一种新型水凝胶（TraceIT；Augmenix公司，马萨诸塞州沃尔瑟姆），并与当前纱布填塞的标准方法进行比较，以及在宫颈癌近距离治疗计划中用于保护危及器官的情况。
本近距离治疗尸体研究使用T2加权MRI和CT成像来比较三种情况：（1）单独使用纱布填塞，（2）将水凝胶注射到宫颈穹窿和直肠阴道隔，（3）纱布填塞结合水凝胶注射。评估水凝胶的分布情况。收集直肠、膀胱和乙状结肠2厘米体积的剂量（D）。使用双尾配对t检验评估统计学显著性（p < 0.05）。
在所有五具尸体中，水凝胶均成功注射，使膀胱和直肠与子宫颈隔开。在CT和MRI上都很容易识别出间隔物。除了填塞外使用水凝胶导致直肠D剂量降低22%（p = 0.02），膀胱D剂量降低10%（p = 0.27），乙状结肠D剂量无变化。仅使用水凝胶与仅使用纱布填塞之间未观察到差异。
我们的结果显示，除了纱布填塞外使用水凝胶可使直肠D有显著的临床意义降低——TraceIT水凝胶有望作为宫颈癌治疗中的间隔物。
