As of December 2024, follow-up was conducted for 37 (17, 52) months with a follow-up rate of 100%. There were 33 survivors (46.5%) and 38 deaths (53.5%). The complete response (CR) rate was 57.7% (41/71), the partial response (PR) rate was 31.0% (22/71), the stable disease (SD) rate was 5.6% (4/71), and the progressive disease (PD) rate was 5.6% (4/71); the local control rate was 94.3% (67/71). The patient’s LPFS rates at 1, 3, and 5 years were 74.6%, 29.5%, and 1.4%, respectively, with a median LPFS duration of 22 (12, 38) months. The overall survival (OS) rates at the same intervals were 88.7%, 47.8%, and 12.6%, with a median OS of 35(23, 48) months. Among the 28 patients who received initial treatment, the median LPFS duration was 25 (16, not reached) months, and the median OS was 47 (26, not reached) months, with OS rates at 1, 3, and 5 years reported as 94.1%, 59.6%, and 27.1%, respectively. In contrast, the cohort of 43 patients with residual or recurrent disease exhibited a median LPFS duration of 13 (7, 23) months and a median OS of 15 (9, 49) months, with OS rates at 1, 3, and 5 years of 85.2%, 40.1%, and 3.2%, respectively. Out of 52 patients who experienced disease progression after particle implantation therapy, 55.7% (29/52) had intrahepatic recurrence or metastasis, and 44.2% (23/52) had extrahepatic metastasis or combined intrahepatic recurrence and extrahepatic metastasis. Following progression, 55.7% (29/52) received local treatment (TACE, ablation, or particle implantation therapy), 15.3% (8/52) received systemic therapy (targeted therapy alone, immunotherapy, or in combination with local treatment), and 29.0% (15/52) received palliative supportive care.

35.2% (25/71) of patients experienced postoperative complications, including 20 cases of hepatic hemorrhage, all of which improved with symptomatic treatment; 4 cases of pleural effusion, 6 cases of pneumothorax, 2 cases of ascites, and one case each of sepsis, liver abscess, and obstructive jaundice, all of which improved after treatment. There were no cases of liver failure, hepatic rupture, or enteric fistula. A total of 53.5% (38/71) of patients died, with potential causes of death including local progression (10 cases), distant metastasis (12 cases), and others due to diabetic nephropathy, cerebral hemorrhage, infection, trauma, and pulmonary embolism.

The univariate analysis data on LPFS and OS in 71 patients with hepatocellular carcinoma following 125I particle implantation are shown in Table 2. Cox univariate analysis of LPFS suggests that the Child-Pugh classification of liver function, the presence or absence of extrahepatic metastasis, the presence or absence of portal vein tumor thrombus, the maximum diameter of the lesions, the Barcelona Clinic Liver Cancer (BCLC) staging, previous treatment history, and recent therapeutic response are all significantly associated with LPFS (all P < 0.05). Then, the significant variables from univariate analysis results were included in multivariate Cox analysis. The results indicated that CR (HR = 0.002, 95% CI: 0.001 to 0.146) is a protective factor for LPFS.

Univariate Cox analysis of OS revealed that the aforementioned eight factors, as well as disease progression after particle implantation therapy and subsequent treatment methods, are all significantly associated with OS (all P < 0.05). Multivariate analysis results revealed that CR (HR = 0.121, 95% CI: 0.023 to 0.642) is a predictive factor for improved OS, while BCLC stage C (HR = 0.190, 95% CI: 0.061 to 0.595), intrahepatic progression after particle therapy (HR = 0.309, 95% CI: 0.093 to 1.030), and extrahepatic metastasis (HR = 0.042, 95% CI: 0.003 to 0.577) are risk factors, with survival curves shown in Fig. 1. Specific case examples are presented in Figs. 2 and 3.

Kaplan-Meier survival analysis in 71 HCC patients post-125I particle implantation therapy. (a) LPFS comparison between CR (41 cases) and non-CR groups (30 cases, PR + SD + PD). (b) OS comparison between CR (41 cases) and non-CR groups (30 cases). (c) OS comparison between BCLC Stage A + B (45 cases) and Stage C (26 cases). (d) OS comparison among patients with no progression (19 cases), intrahepatic progression (29 cases), and extrahepatic metastasis (23 cases) following 125I particle implantation

Case of a 72-year-old male patient. In January 2023, he underwent MRI (A) due to elevated alpha-fetoprotein (AFP) levels, which revealed a new hepatic lesion in segment VIII (3.6 cm) with restricted diffusion and heterogeneous enhancement. Biopsy confirmed hepatocellular carcinoma. Given the patient’s advanced age and the location of the lesion at the diaphragmatic dome, he underwent CT-guided 125I particle implantation for liver cancer in February 2023 (B). A follow-up CT scan six months postoperatively (C) showed significant reduction in the lesion. In May 2024, an acoustic contrast imaging of abdominal organs (D) detected a new hypoechoic lesion in the left liver (2.8 cm), suggestive of liver cancer recurrence. The patient subsequently underwent ultrasound-guided radiofrequency ablation of the hepatic tumor in May 2024. After 125I particle implantation, the patient achieved partial remission at three months, with a local progression-free survival (LPFS) of 15 months and an overall survival (OS) of 22 months

A 71-year-old male patient. In January 2023, a CT scan performed for pneumonia revealed a hepatic segment IV mass (4.2 × 3.3 cm). Biopsy confirmed hepatocellular carcinoma. In February 2023, the patient underwent transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA), followed by oral lenvatinib for anti-tumor therapy. MRI and CT scans in October 2023 showed post-intervention changes (A and B). However, a significant increase in serum AFP levels suggested local tumor recurrence. In November 2023, based on the patient’s strong preference, a CT-guided 125I particle implantation was performed (C). Three months post-implantation, the tumor size remained unchanged, but serum AFP levels significantly decreased. In November 2024, MRI revealed a new nodule in hepatic segment VIII, indicative of intrahepatic metastasis (D, black arrow). The patient achieved partial response three months after 125I particle implantation, with a local progression-free survival (LPFS) of 12 months and an overall survival (OS) of 13 months

A subgroup analysis was conducted on 52 patients who progressed after treatment. Among them, the median OS was 33 months for the 29 patients with intrahepatic progression and 24 months for the 23 patients with extrahepatic metastasis (t = 1.819, P = 0.075). The median OS times for the 29 patients who received local therapy, the 8 patients who received systemic therapy, and the 15 patients who received palliative supportive care were 34, 28, and 16 months, respectively (F = 15.684, P = 0.016).