Radiation Oncology, Cancer Disease Hospital, Lusaka, Zambia.
Radiation Oncology, BC Cancer, Kelowna, British Columbia, Canada.
Brachytherapy. 2020 May-Jun;19(3):316-322. doi: 10.1016/j.brachy.2020.02.004. Epub 2020 Mar 28.
Cervical cancer is the leading cause of cancer mortality of women in low-/middle-income countries. Interstitial needles improve outcomes but require resources beyond those available in endemic regions. We conducted a retrospective review of the use of interstitial needles in locally advanced cervical cancer and simulated both 3D planning without needles and 2D planning to explore the benefit of interstitial needles.
57 brachytherapy plans of 17 patients who had intracavitary tandem and ring plus interstitial brachytherapy were reviewed. Prescribed dose was 7 Gy × four fractions. 2D plans prescribed to point A were generated to represent a standard Manchester loading. Dosimetric outcomes to clinical target volume and organs at risk (OARs) were compared with those of 3D-based plans.
High-risk clinical target volume coverage was excellent: 93.2% for 2D plans, 93.9% for 3D plans without needles, and 96.2% for 3D with needles. The mean dose to 90% of target was 8.5 Gy/fraction for 2D plans, 7.5 for 3D without needles, and 7.9 Gy/fraction for 3D with needles. However, the 2D plans delivered 12% above recommended dose constraints for OARs (except rectum). Dosimetric differences were found between 3D planning and 3D with needles for target coverage (p = 0.002). Dose to OARs was significantly lower when 3D plans with needles were compared with 2D plans.
Interstitial needles provide an optimal therapeutic ratio for patients with high-volume disease or/and unfavorable topography. This justifies additional capital investment in resources for implementation to provide optimal treatment for locally advanced cervical cancer globally.
宫颈癌是中低收入国家女性癌症死亡的主要原因。间质针能改善治疗效果，但需要超出流行地区现有资源的支持。我们对局部晚期宫颈癌中应用间质针的情况进行了回顾性研究，并对无针 3D 计划和 2D 计划进行了模拟，以探讨间质针的益处。
对 17 例接受腔内后装治疗和环加间质近距离治疗的患者的 57 例近距离治疗计划进行了回顾性研究。规定剂量为 7Gy×4 个分次。生成了代表标准曼彻斯特加载的点 A 处方剂量的 2D 计划。比较了临床靶区和危及器官（OARs）的剂量学结果与基于 3D 的计划。
高危临床靶区覆盖率非常好：2D 计划为 93.2%，无针 3D 计划为 93.9%，有针 3D 计划为 96.2%。2D 计划的靶区 90%的平均剂量为 8.5Gy/分次，无针 3D 计划为 7.5Gy/分次，有针 3D 计划为 7.9Gy/分次。然而，2D 计划对 OARs（除直肠外）的推荐剂量限制的 12%以上。3D 计划与有针 3D 计划之间在靶区覆盖方面存在差异（p=0.002）。与 2D 计划相比，有针 3D 计划的 OAR 剂量明显降低。
间质针为大体积疾病或/和不利的肿瘤学患者提供了最佳的治疗比。这证明了在资源方面进行额外的资本投资以实施治疗，从而为全球局部晚期宫颈癌提供最佳治疗是合理的。
