Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland.
Faculty of Medicine, Geneva University, Geneva, Switzerland.
Br J Radiol. 2021 Apr 1;94(1120):20200931. doi: 10.1259/bjr.20200931. Epub 2021 Jan 22.
The aim of this pilot study was to investigate in two rectal cancer patients undergoing neoadjuvant chemo-radiotherapy (nCRT) the implant feasibility and dosimetric benefit in sexual organ-sparing of an injectable, absorbable, radiopaque hydrogel spacer.
Two rectal cancer patients (one male and one female) underwent hydrogel implant between rectum and vagina/prostate before nCRT and curative surgery. A CT scan was performed before and after injection and a comparative dosimetric study was performed testing a standard (45/50 Gy) and a dose escalated (46/55.2 Gy) schedule.
In both patients, the spacer implant in the recto-prostatic or recto-vaginal space was feasible and well tolerated. For the male, the dosimetric benefit with spacer was minimal for sexual organs. For the female however, doses delivered to the vagina were significantly reduced with spacer with a mean reduction of more than 5 Gy for both regimens.
For organ preservation protocols and selected sexually active female patients, use of hydrogel spacers can be considered to spare sexual organs from the high radiotherapy dose levels.
For females with advanced rectal tumor, a spacer implant between the rectum and the vagina before nCRT is feasible and reduces doses delivered to the vagina.
本初步研究旨在调查两名接受新辅助放化疗（nCRT）的直肠癌患者，在保留性器官方面，一种可注射、可吸收、放射可显影的水凝胶间隔物的植入可行性和剂量学优势。
两名直肠癌患者（1 名男性和 1 名女性）在 nCRT 前和根治性手术前在直肠和阴道/前列腺之间植入水凝胶。在注射前后进行 CT 扫描，并进行了比较剂量学研究，测试了标准（45/50Gy）和剂量递增（46/55.2Gy）方案。
在这两名患者中，直肠前列腺或直肠阴道间隙的间隔物植入都是可行的且耐受性良好。对于男性，间隔物对性器官的剂量学优势很小。然而，对于女性，使用间隔物后阴道接受的剂量显著降低，两种方案的平均降低超过 5Gy。
对于器官保留方案和选定的有性生活的女性患者，可以考虑使用水凝胶间隔物，将高放射剂量水平对性器官的影响降到最低。
对于患有晚期直肠肿瘤的女性，在 nCRT 前在直肠和阴道之间植入间隔物是可行的，并可降低阴道接受的剂量。
