Emergent Role of Intra-Tumor Radioactive Implantation in 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.