CT-Guided Iodine-125 Seed Implantation Shows Short-Term Efficacy in Inoperable Pancreatic Cancer

A six-month follow-up study published in BMC Cancer reports that CT-guided iodine-125 particle implantation achieved significant short-term tumor response and pain relief in 84 patients with pancreatic cancer who were not candidates for surgical resection. The study was designed to follow patients for six months after the implantation procedure and collect the clinical factors associated with recent efficacy. The objective response rate reached 76.2 percent, the mean pain score fell from 5.55 to 3.69 on the visual analogue scale, and only five patients experienced complications requiring intervention.

The analysis also identified three independent predictors of short-term efficacy: patient age, tumor size, and postoperative D90. The researchers followed the patients for six months after the procedure and assessed tumor response at the end of that period. Of the 84 patients included, 5 achieved a complete response, 59 a partial response, 8 stable disease, and 12 progressive disease.

Counting complete and partial responses together yielded the objective response rate of 76.2 percent, while the local control rate, which additionally includes stable disease, was 85.7 percent, meaning 72 of the 84 patients had their disease controlled locally at the six-month assessment. Pain relief was statistically significant: the mean visual analogue scale score decreased from 5.55 ± 1.89 before the procedure to 3.69 ± 1.96 at six months (P < 0.001). Safety outcomes were favorable, with five cases of intervention-requiring complications in the cohort: 2 cases of bleeding, 1 pancreatic fistula, and 2 cases of pancreatitis.

To determine which factors influenced these outcomes, the team first performed univariate analysis, which identified patient age and postoperative D90 as statistically significant variables. Tumor size, tumor stage, and particle activity showed trends toward association with efficacy but did not reach statistical significance at this stage. When the variables were entered into multivariate logistic regression, three emerged as independent predictors of short-term efficacy: age, tumor size, and postoperative D90.

Age and tumor size were negatively correlated with efficacy, meaning younger patients and those with smaller tumors tended to have better responses, while a higher postoperative D90 was positively associated with efficacy. The authors conclude that CT-guided iodine-125 particle implantation for pancreatic cancer in patients not candidates for surgical resection shows short-term efficacy, provides effective pain relief, and carries a low rate of complications in this cohort. They note that the follow-up period was limited to six months, so the results address recent, or short-term, efficacy rather than long-term outcomes.

The identification of age, tumor size, and postoperative D90 as independent predictors forms the study's central contribution, quantifying which variables were associated with response in this population.

Subject of Research: Short-term efficacy and predictive factors of CT-guided iodine-125 particle implantation in pancreatic cancer patients not candidates for surgical resection

Article Title: Analysis of factors influencing the recent efficacy of CT‑guided iodine‑125 particle implantation in patients with pancreatic cancer who were not candidates for surgical resection

Article References: Kang, F., Zhang, P., Tian, L., Bu, W., Wang, Q., Wang, F., & Song, J. (2026). Analysis of factors influencing the recent efficacy of CT‑guided iodine‑125 particle implantation in patients with pancreatic cancer who were not candidates for surgical resection. BMC Cancer. https://doi.org/10.1186/s12885-026-17169-7

Image Credits: AI Generated

DOI: 10.1186/s12885-026-17169-7

Keywords: pancreatic cancer, iodine-125, CT-guided particle implantation, D90, objective response rate, pain reduction, predictive factors, unresectable pancreatic cancer, short-term efficacy, BMC Cancer, Analysis, factors