Radioactive Iodine-125 in Tumor Therapy: Advances and Future Directions

Abstract

Radioactive iodine-125 (I-125) is the most widely used radioactive sealed source for interstitial permanent brachytherapy (BT). BT has the exceptional ability to deliver extremely high doses that external beam radiotherapy (EBRT) could never achieve within treated lesions, with the added benefit that doses drop off rapidly outside the target lesion by minimizing the exposure of uninvolved surrounding normal tissue. Spurred by multiple biological and technological advances, BT application has experienced substantial alteration over the past few decades. The procedure of I-125 radioactive seed implantation evolved from ultrasound guidance to computed tomography guidance. Compellingly, the creative introduction of 3D-printed individual templates, BT treatment planning systems, and artificial intelligence navigator systems remarkably increased the accuracy of I-125 BT and individualized I-125 ablative radiotherapy. Of note, utilizing I-125 to treat carcinoma in hollow cavity organs was enabled by the utility of self-expandable metal stents (SEMSs). Initially, I-125 BT was only used in the treatment of rare tumors. However, an increasing number of clinical trials upheld the efficacy and safety of I-125 BT in almost all tumors. Therefore, this study aims to summarize the recent advances of I-125 BT in cancer therapy, which cover experimental research to clinical investigations, including the development of novel techniques. This review also raises unanswered questions that may prompt future clinical trials and experimental work.

Re-Irradiation for Recurrent Cervical Cancer: A State-of-the-Art Review

“…The introduction of an image navigation system provides better accuracy and feasibility, which tracks the needle position in real-time by a tracer to locate the lesion on the fusion image, guiding the puncture procedure. In numerous studies, it has been used for the treatment of solid tumors using seed implantation, with a great puncture accuracy [ 70 , 71 ]. Moreover, Ji et al [ 72 ] suggested that there was no significant difference in dosimetric parameters between post-operative and preoperative plans, regardless of the type of organ, including head and neck, chest wall, and abdominopelvic lesions.…”

Iodine-125 seeds insertion with trans-arterial chemical infusion for advanced lung cancer: a meta-analysis

“…Along with the development of interventional therapy, computed tomography (CT)-guided iodine-125 ( 125 I) seeds insertion (ISI) and trans-arterial chemical infusion (TAI) have been widely used for advanced non-smallcell LC (NSCLC) [4][5][6][7][8][9][10]. The advantages of interventional therapies include mini-invasive nature and lower treat-ment-related toxicity.…”

A retrospective study on unresectable or inoperable head and neck cancers treated with stereotactic ablative brachytherapy

“…In this technique, a radioactive source with a short range and strong penetrating power is applied in contrast to conventional radiation therapy. Therefore, once implanted into target area, it provides an uninterrupted and stable short-range irradiation, with lesser damage to surrounding normal tissues [ 11 ]. This technique is easy to operate, and provides effective radio-protection, because its’ energy decays with distance [ 12 ].…”