Sakamoto Soichiro, Ando Ken, Kumazawa Takuya, Oike Takahiro, Ohno Tatsuya
Department of Radiation Oncology, Gunma University Graduate School of Medicine, Maebashi, JPN.
Cureus. 2025 Feb 18;17(2):e79253. doi: 10.7759/cureus.79253. eCollection 2025 Feb.
Metastasis of a colorectal primary tumor to the vagina is an uncommon condition, and its treatment strategies have not been well established. Computed tomography (CT)-guided intracavitary-interstitial (IC-IS) brachytherapy uses a few interstitial needles, in addition to conventional intracavitary applicators (such as the Fletcher-Suit applicator or vaginal cylinder), and achieves conformal dose distribution to bulky and/or irregularly shaped tumors. Here, we report a first case of an oligometastatic vaginal tumor from the colorectum that was treated successfully with radiotherapy using CT-based IC-IS brachytherapy. External beam radiotherapy (EBRT), followed by four sessions of IC-IS brachytherapy, resulted in a satisfactory dose prescription to the target while sparing normal organs adjacent to the tumor. This led to radiological complete remission of the tumor over at least six months, with no severe adverse effects. This case indicates that radiotherapy using CT-based IC-IS brachytherapy may be a viable treatment option for metastatic vaginal tumors.
结直肠癌原发肿瘤转移至阴道是一种罕见的情况，其治疗策略尚未完全确立。计算机断层扫描（CT）引导下的腔内-组织间（IC-IS）近距离放射治疗除了使用传统的腔内施源器（如弗莱彻-休特施源器或阴道柱状施源器）外，还使用几根组织间针，可实现对体积较大和/或形状不规则肿瘤的适形剂量分布。在此，我们报告首例采用基于CT的IC-IS近距离放射治疗成功治愈的结直肠癌寡转移阴道肿瘤病例。外照射放疗（EBRT）后进行4次IC-IS近距离放射治疗，在保护肿瘤邻近正常器官的同时，实现了对靶区满意的剂量处方。这使得肿瘤在至少6个月内实现了影像学完全缓解，且无严重不良反应。该病例表明，基于CT的IC-IS近距离放射治疗可能是转移性阴道肿瘤的一种可行治疗选择。
