Iodine-125 Brachytherapy Prophylaxis after Radiofrequency Ablation Cannot Benefit Patients in High Risk of Locoregional Hepatocellular Carcinoma Recurrence

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

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.

Combined Ultrasound and CT-Guided Iodine-125 Seeds Implantation for Treatment of Residual Hepatocellular Carcinoma Located at Complex Sites After Transcatheter Arterial Chemoembolization

Purpose

The purpose of this study was to evaluate the efficacy and safety of iodine-125 (¹²⁵I) seeds implantation under ultrasound and computed tomography (CT) guidance in the treatment of residual hepatocellular carcinoma (HCC) located at complex sites after transcatheter arterial chemoembolization (TACE).

Methods

This retrospective study analyzed the consecutive medical records of 31 HCC patients with residual tumors located at complex sites (such as large blood vessels, gallbladder, diaphragm dome, etc.) after TACE from May 2014 to December 2018, all of whom received ¹²⁵I seeds implantation therapy. Overall survival (OS), progression-free survival (PFS), recurrence, and complications were documented.

Results

A total of 607 seeds were implanted in 31 patients, with an average of 19.6±10.4 (range, 8–48) seeds per patient. Median OS and PFS were 33 months (95% CI: 27.1 months, 38.9 months) and 15 months (95% CI: 9.6 months, 20.4 months), respectively. Although univariate analysis showed that albumin, prothrombin time, alpha-fetoprotein level, Child-Pugh score, and lipiodol deposition in tumor were associated with OS, multivariate analysis showed that none of them was an independent prognostic factor for OS. Multivariate analysis showed that prothrombin time was an independent prognostic factor for PFS. No operation-related deaths in this study. Although pneumothorax was present in two patients and subcutaneous abscess in one patient, symptoms improved in all three patients with appropriate treatment. Common minor complications included fever, abdominal pain and leukopenia and no grade≥3 adverse events were observed.

Conclusions

¹²⁵I seeds implantation under the combined guidance of ultrasound and CT is safe and effective for patients with residual HCC located at complex sites after TACE. This is a promising treatment approach and deserves further discussion.

125I implantation under computed tomography guidance to treat patients with recurrent pelvic tumors: Retrospective analysis of clinical results

Objective

The objective of the study was to evaluate computed tomography (CT)-guided ¹²⁵I implantation for the treatment of recurrent and malignant pelvic tumors.

Materials and Methods

Fifteen cases of pelvic malignant tumors were studied. Tumor length/diameter was 4-10 cm (average: 6.8 ± 2.3 cm). In patients with pelvic recurrence or metastasis of malignant tumors, comprehensive treatment, including surgery, chemotherapy, or radiotherapy, was performed alongside CT-guided ¹²⁵I implantation. The follow-up clinical benefit rate, rate of pain relief, quality of life score, and status of any complications were analyzed.

Results

The patients were followed up for 6 months after the operation, and evaluation of lesions revealed complete response (CR) in 3/15 cases, partial response (PR) in 8/15 cases, stable disease in 3/15 cases, and progressive disease in 1/15 cases. The total effective rate (CR + PR) was 73.3% (11/15), and the pain relief rate was 86.6% (13/15). No bleeding, pelvic abscesses, intestinal fistulas, intestinal perforations, or other complications were reported.

Conclusions

When using CT-guided ¹²⁵I implantation, patients with malignant abdominal tumors undergo a convenient operation, sustain little trauma, and have an improved quality of life.

Feasibility, safety, and long-term efficacy of stereotactic radiofrequency ablation for tumors adjacent to the diaphragm in the hepatic dome: a case-control study

Objectives

Achievement of adequate treatment margins may be challenging when the target is either difficult to visualize, awkward to access, or situated adjacent to vulnerable structures. Treatment of tumors located close to the diaphragm in the hepatic dome is challenging for percutaneous radiofrequency (RF) ablation for these reasons. The purpose was to assess the feasibility, safety, and clinical outcome of multi-probe stereotactic RF ablation (SRFA) of liver tumors in the subdiaphragmatic area.

Methods

Between 2006 and 2018, 177 patients (82 HCCs, 6 ICCs, and 89 metastatic tumors) underwent SRFA of 238 tumors abutting the diaphragm in the hepatic dome. For comparison, 177 patients were randomly selected from our database by the R package “MatchIt” for propensity score matching to compare treatment safety and efficacy in this retrospective, single-center study.

Results

Median treated tumor size was 2.2 cm (range 0.5 to 10 cm). SRFA was primarily successful for 232/238 (97.5%) tumors. Five tumors were successfully retreated, resulting in a secondary technical efficacy rate of 99.6%. Local tumor recurrence developed in 21 of 238 tumors (8.8%). The major ablation complication rate was 10.7% (22 of 204). Twelve (55%) of 22 major complications could be successfully treated by the interventional radiologist in the same anesthesia session. There was no significant difference in adverse events or disease control rates between the subdiaphragmatic tumors and matched controls.

Conclusions

SRFA is a safe and feasible option in the management of difficult-to-treat tumors abutting the diaphragm in the hepatic dome, with similar safety profile compared with matched controls.

Key Points

• RFA was primarily successful for 232/238 (97.5%) subdiaphragmatic dome tumors. Local tumor recurrence developed in 21 of 238 tumors (8.8%).

• The major complication rate directly related to ablation of the hepatic dome tumors was 10.7% (22 of 204). 12/22 (55%) of major complications could be successfully treated in the same anesthesia session.

• There was no significant difference in adverse events or disease control rates between the subdiaphragmatic tumors and matched controls.