Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran.
Radiation Oncology department, Cancer Institute, Tehran University of Medical Sciences, Tehran, Iran.
Biomed Phys Eng Express. 2021 Aug 19;7(5). doi: 10.1088/2057-1976/ac1c52.
. Radioisotope ofIradium (Ir) has a half-life (74 days) and is not easily accessible in developing countries. As a result, by the time source shipment clearance and the customs paperwork are completed, a large proportion of useful activity had already been decayed away. In fact,Cobalt (Co) remote afterloading systems are commercially available by many venders. As a result, it may well become an alternative source toIr and conform many of these challenges. The aim of this study is that to report clinical responses of different types of gynaecological cancers treated with high dose rate (HDR)Ir and HDRCo brachytherapy in order to check whether HDRCo could be used as an alternative brachytherapy, source to HDRIr.. A retrospective study of clinical responses of different types of gynaecological cancers, staged from I to IV according to recommendations of International Federation of Gynaecology and Obstetrics (FIGO), treated by brachytherapy alone, radiotherapy alone (combined brachytherapy and radiotherapy) and combined radiotherapy and chemotherapy (brachytherapy, radiotherapy and chemotherapy) between 1984 and December 2020 was conducted. The patients were treated with external beam radiotherapy 45-51 Gy boosted with HDRIr and HDRCo afterloading brachytherapy of 18-30 Gy to point A.. The study scrutinized the data of 11086 patients with different types of gynaecological cancers. Most of the patients, 70 percent of them, were diagnosed with gynaecological cancers in stages II and III. For patients treated withIr brachytherapy source 5-years overall survival rate (OS), local control, 2-years, 5-years and 10-years disease free survival (DFS), complications of gastro-intestine (GI) and complications of genito-urinary (GU) were 63.5%, 92%, 72.6%, 64.07%, 43.75%, 3.9% and 5.92%, but for those treated withCo they were 57.7%, 86.63%, 82.5%, 53.35%, 43.75%, 4.8% and 3.7%, respectively.The use of HDRCo brachytherapy has the capacity to produce overall survival rate and disease control in patients with carcinoma of the gynaecology comparable to that reported for HDRIr brachytherapy. Currently, the toxicity and damage of the normal tissues and radiation-related second cancers are of a similar incidence to that of standard HDRIr brachytherapy. Source exchange frequency is not a serious concern because it requires less frequency of replacement, and commissioning can be accomplished within years; hence, replacing HDRIr with HDRCo brachytherapy achieves significant cost saving. Therefore, we recommend thatCo source ought to be the first choice for low resource radiotherapy setting as it offers economic advantages overIr and have comparable clinical outcomes to that ofIr source.
镭-223（Ir）的放射性同位素半衰期为 74 天，在发展中国家不易获得。因此，在完成源运输清关和海关文件工作时，大量有用的放射性活度已经衰变。事实上，许多供应商都有钴（Co）远程后装治疗系统可供商业使用。因此，它很可能成为 Ir 的替代源，并满足许多这些挑战。本研究的目的是报告用高剂量率（HDR）Ir 和 HDRCo 近距离治疗不同类型妇科癌症的临床反应，以检查 HDRCo 是否可以用作替代 HDRIr 的近距离治疗源。
对 1984 年至 2020 年 12 月期间，根据国际妇产科联合会（FIGO）的建议，单独接受近距离治疗、单独接受放疗（联合近距离治疗和放疗）以及联合放疗和化疗（近距离治疗、放疗和化疗）治疗的不同类型妇科癌症的患者进行了回顾性研究。患者接受外部束放疗 45-51 Gy，并在 HDRIr 和 HDRCo 后装近距离治疗 18-30 Gy 至 A 点。
研究检查了 11086 名不同类型妇科癌症患者的数据。大多数患者（70%）患有 II 期和 III 期妇科癌症。接受 Ir 近距离治疗源治疗的患者的 5 年总生存率（OS）、局部控制、2 年、5 年和 10 年无病生存率（DFS）、胃肠道（GI）并发症和泌尿生殖系统（GU）并发症分别为 63.5%、92%、72.6%、64.07%、43.75%、3.9%和 5.92%，而接受 Co 治疗的患者则为 57.7%、86.63%、82.5%、53.35%、43.75%、4.8%和 3.7%。使用 HDRCo 近距离治疗有可能产生与 HDRIr 近距离治疗报告的相似的妇科癌患者的总生存率和疾病控制率。目前，正常组织的毒性和损伤以及与辐射相关的第二癌症的发生率与标准 HDRIr 近距离治疗相似。源交换频率不是一个严重的问题，因为它需要较少的更换频率，并且可以在几年内完成调试；因此，用 HDRCo 近距离治疗代替 HDRIr 可以显著节省成本。因此，我们建议 Co 源应成为资源有限的放射治疗环境的首选，因为它在经济上优于 Ir，并且与 Ir 源的临床结果相当。
