# Emergent Role of Intra-Tumor Radioactive Implantation in Pancreatic Cancer

## TL;DR

This review explores the use of radioactive implantation via endoscopic ultrasound to treat pancreatic cancer, showing promise in tumor control and safety.

## Contribution

The paper highlights the novel use of phosphorus-32 brachytherapy for locally advanced pancreatic cancer via EUS-guided delivery.

## Key findings

- Phosphorus-32 microparticle brachytherapy shows significant tumor regression and improved CA 19-9 levels.
- The treatment spares healthy tissue and can be combined with chemotherapy without interruption.
- Preliminary evidence suggests it improves tumor vascularity and chemotherapy effectiveness.

## Abstract

Pancreatic ductal adenocarcinoma remains a silent killer and is in dire need of more effect therapeutic strategies. Endoscopic ultrasound (EUS) has expanded its repertoire over the last two decades and can be used as a mode of treatment delivery directly into pancreatic tumors. In this review, we provide details on EUS-guided intra-tumoral fine-needle injectional therapies, highlighting the use of intra-tumoral radioactive implantation in patients with locally advanced pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, with limited treatment options for patients with locally advanced or metastatic disease. Endoscopic ultrasound (EUS)-guided intra-tumoral radioactive implantation has emerged as a minimally invasive approach to enhance local tumor control while minimizing systemic toxicity. Among the available isotopes, phosphorus-32 (32P) microparticle brachytherapy has demonstrated promising outcomes, including significant tumor regression, reductions in CA 19-9, and higher rates of tumor downstaging and surgical conversion when combined with systemic chemotherapy. Compared with stereotactic body radiotherapy (SBRT), 32P delivers higher intratumoral radiation doses, spares adjacent healthy tissues, and can be administered during ongoing chemotherapy without treatment interruption. Additionally, preliminary evidence suggests that 32P may modulate the tumor microenvironment, improving vascularity and enhancing chemotherapy efficacy. The procedure shows high technical success and a favorable safety profile, with minimal serious adverse events. Future directions include prospective randomized trials to validate its impact on survival, optimize dosing, and establish treatment protocols. EUS-guided intra-tumoral 32P brachytherapy holds potential as a key component of multimodal therapy, bridging local tumor control and systemic disease management in PDAC.